Chinook Salmon (Oncorhynchus tshawytscha): COSEWIC assessment and status report 2018 : page 3

• Previous page
• Table of contents
• Next page

Threats and limiting factors

Many DUs were assigned a general risk rating using the IUCN threats calculator (the calculator), a fillable Excel spreadsheet that can be completed on a DU-by-DU basis to evaluate threats and limiting factors.

The calculator characterizes threats to DUs based on scope, severity, and timing. Scope is defined as the percentage of the species reasonably expected to be affected by the threat within 10 years. Severity is the level of damage (percent population loss) to the species from the threat that can reasonably be expected within 10 years or three generations (whichever is longer), if current circumstances and trends continue. Timing is defined as the projected and estimated duration of the threat over the next 10 years or three generations (whichever is longer).

Scope, severity and timing rankings are assigned based on cumulative scores for eleven different threat categories comprised of forty different sub-categories. Main threat categories include:

1. Residential and commercial development
2. Agriculture and aquaculture
3. Energy production and mining
4. Transportation and service corridors
5. Biological resource use
6. Human intrusions and disturbance
7. Natural system modifications
8. Invasive and other problematic species and genes
9. Pollution
10. Geological events
11. Climate change and severe weather

Each sub-category is assigned a score ranging from Negligible to Pervasive (scope), Negligible to Extreme (severity), and Insignificant/Negligible to High-continuing (timing), with uncertainty ranges and Unknown or Neutral options also available. Once scores are assigned to each sub-category, the calculator provides a cumulative score for each main category. The roll-up of these main category threats is done manually to provide a grade for the population's overall threat impact, following the interpretations of Master et al. (2012). Threat impact grades include A-Very High; B-High; C-Medium; and D-Low.

Threats calculators were produced for this report using a two-stage approach. The first stage relied on literature, document review and existing data (reported here). This method supplied relevant information regarding threats and limiting factors for each DU and permitted the production of a preliminary set of threats calculator results.

Some of the metrics used to evaluate threats (for example, harvest, mortality) are based on information gathered from indicator stocks, which have coded-wire tag (CWT) individuals released from hatcheries. DUs with CWT indicator stocks are listed in Table 17. For those DUs without indicator stocks, proxy indicator stocks were used.

^b The Nooksack River Fall Fingerling (NKF) indicator stock in Washington State, USA was used as the proxy indicator stock for DU1 (CU CK-02).

One challenge was quantifying severity because a direct causal link could not be established between most threats/limiting factors and impacts to populations. However, in some populations, metrics (for example, harvest) could be quantified if there was an indicator stock present. This preliminary method did not provide sufficient depth and breadth to assign final threats calculator grades, but it did supply useful data informing the next stage.

For the second stage, a workshop of Chinook Salmon experts was convened in Nanaimo, BC in February 2017 to apply the IUCN threats calculator to Southern BC Chinook Salmon. This group of experts reviewed data supplied by the first stage and added new information based on expert knowledge of different DUs. The workshop provided a rich source of data, fleshing out the previous information and permitting the completion of threats calculator grading for several DUs as well as the assignment of proxy DUs for other DUs that could not be completed at the workshop. Table 18 shows the full list of DUs and indicates those that had threats calculators completed at the workshop as well as those that were assigned proxies. Where applicable, notes regarding status, priority levels, other relevant comments, and overall threats calculator grades are supplied.

Figure 33. Map of DU1 – Southern Mainland Boundary Bay Ocean Fall. To be in Part Two.

Figure 34. DU1 – Abundance, enhancement, and hatchery releases (see Table 13 for panel interpretation).

Table 19. Summary of estimated rate of change (±95 percent credible interval) in spawner abundance and probability of decline over the last three generations (>30 percent, >50 percent, >70 percent). Rates of change over the last three generations are provided based on analysis of the last three generations of data as well as the entire time series.

Figure 35. DU1 – Trends in spawner abundance, exploitation rate, and marine (smolt-to-adult) survival (see Table 16 for panel interpretation).

Designatable Unit 2: Lower Fraser, Ocean, Fall population (assessed November 2018)

DU short name

LFR+GStr/Ocean/Fall

Joint Adaptive Zone (JAZ)

LFR+GStr

Life history

Ocean

Run timing

Fall

The average generation time for this DU is 3.8 years. These fish exhibit ocean-type life-history variants and fall run-timing.

To review methods pertaining to data reported within individual DU chapters, refer to the preliminary sections of this report.

Extent of occurrence and area of occupancy

DU2 overlaps DU5 – Lower Fraser River – Stream Summer. The DU stretches from Harrison River to the north (Lat. 49.79, Long. 122.18) to where the Harrison River merges into Fraser River at the south end (Lat. 49.22, Long. 121.94). The eastern extent of the DU reaches to Bear Creek at Lat. 49.56, Long. 121.69, and the westernmost extent is located at Twenty Mile Creek (Lat. 49.56, Long. 121.96). The DU's centroid is located at Lat. 49.22, Long. 121.95 and its total area is 715.85 km².

As for all DUs considered in this report, the extent of occurrence includes spawning streams as well as the ocean range, and is therefore >20,000 km². The IAO is 175 km² based on a total known spawning run length of 87 km, or 0.86 percent of the known spawning length across all DUs.

Habitat trends

Land surrounding this DU's freshwater habitat is altered (10.4 percent), with 0.6 percent of the area dedicated to urban development, and 1.3 percent to agricultural / rural development. Road density in DU2 is 1.0 km/km² with an average of 0.3 stream crossings per km of fish accessible streams (the average across all DUs is 1.33 km/km² road density and 0.62 stream crossings per km of fish accessible streams). 15.2 percent of DU2's riparian habitat is disturbed. The DU contains no mining development nor pine stands affected by Mountain Pine Beetle.

Abundance

All spawner estimates originated from a single site with true abundance data where sampling effort/survey quality was considered high (Figure 37b,d). Twenty-nine generational averages can be generated from relative index spawner time series data, with generational averages for all years estimated at 10,000 spawners or more (Figure 37c).

This DU is enhanced. Of the years where sampling occurred, mature individuals all originated from streams that had low or unknown levels of enhancement (Figure 37a). Hatchery releases increased from the early 1980s to a maximum of 3,184,390 fish annually in 1992 then declined to around 200,000 fish annually by 2005 (Figure 37e). Only one instance is reported of hatchery releases from outside the DU (Figure 37f). This release occurred when Harrison River-origin fish were brought from Chilliwack River due to insufficient brood stock at Harrison River (there is little differentiation between these stocks in accordance with their common origin – see Beacham et al. 2003). DU2 origin releases continue to occur at a number of sites outside the DU.

Fluctuations and trends

Using the last three generations of data, the number of mature individuals changed by an estimated -57 percent (Upper 95 percent CI = 17 percent, Lower 95 percent CI = -84 percent) with the probability of a 30 percent decline at 0.85 (Table 20, Figure 38a,c). Using the entire time series of data, the number of mature individuals changed over the last three generations by an estimated -17 percent (Upper 95 percent CI = 7 percent, Lower 95 percent CI = -35 percent) with the probability of a 30 percent decline at 0.09.

The total exploitation rate declined from a maximum of ~0.9 in 1982 to ~0.3 by 2013 (Figure 38d). The trend from 2005 onward was relatively stable, with exploitation ranging from a rate of approximately 0.4 to 0.2. Marine (smolt-to-adult) survival declined from a maximum of ~0.23 in 1981 and fluctuated between 0.004 and 0.1 from 1982 onwards with a slight downward trend overall (Figure 38e). In 2013 the rate was 0.017. Stock productivity rose to a maximum of ~30 recruits per spawner in 1988 then declined, fluctuating between approximately 1 and 18 recruits per spawner until 2009 (Figure 39). In 2009, productivity was at ~6.5 recruits per spawner.

More recently, escapements to DU2 have declined for all but one brood cycle line. The cause of these declines is uncertain but likely linked to recent poor ocean conditions. Fishing mortality rates have also declined for this DU, and are thought not to be the primary reason for the declines in abundance. The preliminary escapement estimate for 2017 is the second lowest since high precision estimation started in the early 1980s, likely related to the 'warm blob' climate anomaly (Bailey pers. comm. 2018; M. Trudel, pers. comm.).

Threats and limiting factors

For general threats and limiting factors applicable to all DUs, please refer to the Threats and Limiting Factors section in the introductory material. Chinook Salmon experts who participated in the IUCN threats calculator workshop in February 2017 concluded that this DU should be assigned a threat impact of Medium (C). The most important threat specific to this DU is from harvest. The entire population is exposed to fishing. Exploitation rates have been at 20-30 percent for the last ten years and there is a possibility that this rate is higher than sustainable. Several low productivity years have occurred and it is unclear whether the exploitation rate is low enough to compensate. Ecosystem modifications are also relevant because a large portion of the Lower Fraser River and estuary are significantly altered, leading to a loss of critical tide marsh habitat.

Other less important threats include storms and flooding, habitat shifting and alteration, introduced genetic material, problematic native species, invasive species, channel dredging operations, recreational activities, and logging/shipping lanes (tugs and log booms move through spawning grounds and may disturb redds).

Threats calculator spreadsheets are included with this report (see Appendix 1).

Designatable Unit 3: Lower Fraser, stream, spring population (assessed November 2018)

DU short name

LFR+GStr/Stream/Spring

Joint Adaptive Zone (JAZ)

LFR+GStr

Life history

Stream

Run timing

Spring

The average generation time for this DU is 4.5 years. These fish exhibit stream-type life-history variants and spring run-timing.

To review methods pertaining to data reported within individual DU chapters, refer to the preliminary sections of this report.

Extent of occurrence and area of occupancy

This DU is comprised of two connected sections draining into Lillooet Lake. The northernmost section extends south from Birkenhead Lake Provincial Park and the drainage of Birkenhead Lake (Lat. 50.65, Long. 122.71) to the confluence of the Birkenhead River with Lillooet Lake at Lat. 50.30, Long. 122.61. The southernmost section includes the Green River, Torrent Creek, Ipsoot Creek and Ryan River drainages. Its northernmost extent occurs at the headwaters of Ryan River (Lat. 50.49, Long. 123.44) and its southernmost extent occurs south of Whistler, BC near Russet Lake (Lat. 50.01, Long. 122.82). The DU's centroid occurs at Lat. 50.32, Long. 122.72, and its total area is 2030.28 km².

As for all DUs considered in this report, the Extent of Occurrence includes spawning streams as well as the ocean range, and is therefore >20,000 km². The IAO is 105 km² based on a total known spawning run length of 52 km, or 0.52 percent of the known spawning length across all DUs.

Habitat trends

Land surrounding this DU's freshwater habitat is altered (11.9 percent), with urban development covering 1.2 percent of the DU area, agricultural / rural development comprising 0.6 percent, and mining development comprising another 0.06 percent . Road density in DU3 is 1.0 km/km² with an average of 0.4 stream crossings per km of fish accessible streams (the average across all DUs is 1.33 km/km² road density and 0.62 stream crossings per km of fish accessible streams). 12.7 percent of the DU's riparian habitat is disturbed, 10.0 percent of the forest is disturbed, and 0.28 percent of pine stands are killed by Mountain Pine Beetle.

Abundance

No absolute abundance estimates are available for this DU, only relative abundance indices (Figure 41a and Figure 41b). Sampling effort/survey quality at all sample sites is rated moderate, with the exception of 1980, 1981, and 1983, where sampling effort is rated low. This DU is now classified as low enhancement, which means it is grouped into the wild data stream for assessment (Figure 41a). Twenty-nine generational averages can be generated from relative index spawner abundance time series data, with twenty-five indicating a generational average of 250 - 1,000 fish, and the remaining four estimated at less than 250 fish (Figure 41c)

Hatchery releases increased from 1980 to 1990, with a maximum release of ~240,000 in 1983 (Figure 41e). After 1990, hatchery releases stabilized at ~50,000 fish, with the last known hatchery release occurring in 2003. Only one instance is reported of hatchery releases from outside the DU (Figure 41f).

Fluctuations and trends

Using the last three generations of data, the number of mature individuals changed by an estimated -16 percent (Upper 95 percent CI = 217 percent, Lower 95 percent CI = -77 percent) with the probability of a 30 percent decline at 0.38 (Table 21, Figure 42a,b). Using the entire time series of data, the number of mature individuals changed over the last three generations by an estimated 21 percent (Upper 95 percent CI = 60 percent, Lower 95 percent CI = -9 percent) with zero probability of a 30 percent decline.

Harvest, marine (smolt-to-adult) survival, and stock productivity data are unavailable for this DU because there is no coded-wire tag indicator stock.

Threats and limiting factors

For general threats and limiting factors applicable to all DUs, please refer to the Threats and Limiting Factors section in the introductory material. This stock is far north migrating so most harvest occurs in Alaska. Further effort is required (for example, by eliciting expert knowledge) to determine a threat grade using the IUCN threats calculator.

Designatable Unit 4: Lower Fraser, stream, summer (upper Pitt) population (assessed November 2018)

DU short name

LFR+GStr/Stream/Summer (Upper Pitt)

Joint Adaptive Zone (JAZ)

LFR+GStr

Life history

Stream

Run timing

Summer

The average generation time for this DU is 4.5 years. These fish exhibit stream-type life-history variants and summer run-timing.

To review methods pertaining to data reported within individual DU chapters, refer to the preliminary sections of this report.

Extent of occurrence and area of occupancy

This DU extends along Pitt River from the north at Mount Carr (Lat. 49.64, Long. 122.68) to the south at the Fraser River confluence (Lat. 49.23, Long. 122.77). The easternmost extent is at Vickers Creek (Lat. 49.47, Long. 122.43) and the westernmost extent is at Homer Creek (Lat. 49.85, Long. 123.00). The DU's centroid occurs at Lat. 49.64, Long. 122.68, and its total area is 1217.71 km².

As for all DUs considered in this report, the Extent of Occurrence includes spawning streams as well as the ocean range, and is therefore <20,000 km². The IAO is 191 km² based on a total known spawning run length of 95km giving or 0.94 percent of the known spawning length across all DUs.

Habitat trends

Land surrounding this DU's freshwater habitat is altered (10.6 percent), with urban development comprising 2.3 percent of the DU area, agricultural / rural development comprising 2.7 percent, and mining development comprising 0.06 percent. Road density in DU4 is 1.0 km/km² with an average of 0.2 stream crossings per km of fish accessible streams (the average across all DUs is 1.33 km/km² road density and 0.62 stream crossings per km of fish accessible streams). 11.0 percent of the DU's riparian habitat and 5.5 percent of the forest cover is disturbed. There are no pine stands in this DU affected by the Mountain Pine Beetle.

Abundance

No absolute abundance estimates are available for this DU, only relative abundance indices. All observed spawners originated from sample sites with moderate sampling effort/survey quality (Figure 44b). Four generational averages can be calculated from relative index spawner abundance time series data, each estimated at less than 250 spawners (Figure 44c).

Of the years where sampling occurred, mature individuals all originated from streams that had low or unknown levels of enhancement (Figure 44a). Hatchery releases ranging from ~40,000 to ~160,000 fish occurred in the 1980s, but no releases have taken place since 1990 (Figure 44e).

Fluctuations and trends

The entire time series of data is within three generations. Based on these data, the number of mature individuals changed by an estimated -73 percent (Upper 95 percent CI = -32 percent, Lower 95 percent CI = -89 percent) with the probability of a 30 percent decline at 0.98 (Table 22, Figure 45a,b). Note that in Figure 45a, the trend in the data is not necessarily representative of the entire DU. This is because it is a survey of a single tributary of a glacial river population. It is unknown if the tributary spawners form a consistent fraction of the total population.

Harvest, marine (smolt-to-adult) survival, and stock productivity data are unavailable for this DU because there is no coded-wire tag indicator stock.

Threats and limiting factors

For general threats and limiting factors applicable to all DUs, please refer to the Threats and Limiting Factors section in the introductory material. Further effort is required (for example, by eliciting expert knowledge) to determine a threat grade using the IUCN threats calculator. The ocean distribution for this DU is thought to be far north and therefore harvest likely occurs primarily in Alaska. However, due to a later return timing relative to DU3, some harvest also likely occurs in Georgia Strait.

Designatable Unit 5: Lower Fraser, stream, summer population (assessed November 2018)

DU short name

LFR+GStr/Stream/Summer

Joint Adaptive Zone (JAZ)

LFR+GStr

Life history

Stream

Run timing

Summer

The average generation time for this DU is 4.5 years. These fish exhibit stream-type life-history variants and summer run-timing.

To review methods pertaining to data reported within individual DU chapters, refer to the preliminary sections of this report.

Extent of occurrence and area of occupancy

This DU is comprised of two sections extending from the Lillooet River headwaters in the north (Lat. 50.83, Long. 123.76) to the confluence of the Harrison and Fraser rivers in the south (Lat. 49.21, Long. 121.94). The westernmost extent occurs in the northern part along Meager Creek and runs south along Sirenia Mountain (Lat. 50.61, Long. 123.77), the easternmost extent occurs in the southern part east of Harrison Lake (Lat. 49.57, Long. 121.54). The DU's centroid is Lat. 49.70, Long. 122.13, and its total area is 5929.21km².

As for all DUs considered in this report, the extent of occurrence includes spawning streams as well as the ocean range, and is therefore >20,000 km². The IAO is 645 km² based on a total known spawning run length of 323 km, or 3.21 percent of the known spawning length across all DUs.

Habitat trends

Land surrounding this DU's freshwater habitat is altered (10.0 percent), with urban development comprising of 0.09 percent of the DU area, agricultural / rural development comprising 1.2 percent, and mining development comprising 0.02 percent. Road density in DU5 is 1.0 km/km² with an average of 0.6 stream crossings per km of fish accessible streams (the average across all DUs is 1.33 km/km² road density and 0.62 stream crossings per km of fish accessible streams). 11.3 percent of the DU's riparian habitat is disturbed, 8.7 percent of the forest cover is disturbed, and 0.6 percent of pine stands are affected by Mountain Pine Beetle.

Abundance

No absolute abundance estimates are available for this DU, only relative abundance indices. All observed spawners originated from census sites with low and moderate sampling effort/survey quality (Figure 47b). Four generational averages can be calculated from relative index spawner abundance time series data, each with less than 250 spawners (Figure 47c). The available survey data, although considered to be of good quality, reflect relative abundance and it is not known how representative the survey information is of the entire DU.

The number of remaining mature individuals could be less than 1000, assuming that the spawning sites within the DU (Appendix 2) include a similar number as the surveyed population. This assumption cannot be tested.

Of the years where sampling occurred, all mature individuals originated from streams with low or unknown levels of enhancement (Figure 47a). Intermittent hatchery releases occurred both within and outside the DU during the 1980s. After 1990, the number of hatchery releases averaged ~450,000 fish (Figure 47e). The last recorded hatchery release was in 2013. However, DFO notes there is an annual release of hatchery summer Chinook Salmon into the Chehalis River, as well as releases into the Chilliwack River (not currently included within DU boundaries) (Bailey pers. comm. 2018).

Fluctuations and trends

The entire time series of data is within 3 generations. Based on these data, the number of mature individuals changed by an estimated -36 percent (Upper 95 percent CI = 1689 percent, Lower 95 percent CI = -98 percent) with the probability of a 30 percent decline at 0.52 (Table 23, Figure 48a,b).

Harvest, marine (smolt-to-adult) survival, and stock productivity data are unavailable for this DU because there is no coded-wire tag indicator stock.

Threats and limiting factors

For general threats and limiting factors applicable to all DUs, please refer to the Threats and Limiting Factors section in the introductory material. Further effort is required (for example, by eliciting expert knowledge) to determine a threat grade using the IUCN threats calculator. Threats calculator spreadsheets are included with this report (see Appendix 1). This DU experiences ongoing enhancement from releases of summer Chinook Salmon into the Chehalis and Chilliwack rivers. A significant habitat impact in this DU is the channelization and diking in the Lillooet River upstream of Lillooet Lake. Dredging occurs at the Lillooet Lake outlet and the lake's elevation is lowered. Dredging likely removes prime spawning habitat because the lake outlet is formed by a glacial terminal moraine (Bailey pers. comm. 2018).

Designatable Unit 6: Lower Fraser, Ocean, Summer population (not yet assessed)

Tables and Figures to be in Part 2:

Figure 49. Map of DU6 – Lower Fraser River Ocean Summer.

Figure 50. DU6 – Abundance, enhancement, and hatchery releases.

Table 24. Summary of estimated rate of change (±95 percent credible interval) in spawner abundance and probability of decline over the last three generations (>30 percent, >50 percent, >70 percent). Rates of change over the last three generations are provided based on analysis of the last three generations of data as well as the entire time series.

Figure 51. DU6 – Trends in spawner abundance, exploitation rate, and marine (smolt-to-adult) survival.

Designatable Unit 7: Middle Fraser, Stream, Spring (FRCany+GStr) (assessed November 2018)

DU short name

FRCany+GStr/Stream/Spring

Joint Adaptive Zone (JAZ)

FRCany+GStr

Life history

Stream

Run timing

Spring

The average generation time for this DU is 4.5 years. These fish exhibit stream-type life-history variants and spring run-timing.

To review methods pertaining to data reported within individual DU chapters, refer to the preliminary sections of this report.

Extent of occurrence and area of occupancy

There are two geographically separated sections that combine to form this DU. The DU extends from the north at a mountain ridge close to Haynon Lake (Lat.50.12, Long. 122.07) to the south east of Anderson River at Lat. 49.57, Long. 121.23. The DU's western-most extent is at Nahatlatch River (Lat. 49.96, Long. 122.28) and the eastern-most extent occurs at Anderson River at Lat. 48.86, Long. 121.09. The DU's centroid is at Lat. 49.91, Long. 121.48, and its total area is 1705.57 km².

As for all DUs considered in this report, the extent of occurrence includes spawning streams as well as the ocean range and is therefore >20,000 km². The IAO is 103 km² based on a total known spawning run length of 52 km, or 0.52 percent of the known spawning length across all DUs.

Habitat trends

Land surrounding this DU's freshwater habitat is altered (2.7 percent), with agricultural / rural development covering 0.03 percent of the area. Road density in DU7 is 0.3 km/km² with an average of 0.4 stream crossings per km of fish accessible streams (the average across all DUs is 1.33 km/km² road density and 0.62 stream crossings per km of fish accessible streams). 2.9 percent of the DU's riparian habitat and 2.7 percent of the forest cover is disturbed. 2.0 percent of the DU's pine stands are affected by Mountain Pine Beetle. There is no urban development, nor mining development within the DU area.

Abundance

Annual survey estimates for this wildlife species are available from 2009 to 2017, and range from 2 to 65. Even though these estimates are indices, it is not expected that expansion of the indices would result in population sizes greater than 250 mature individuals.

Fluctuations and trends

Harvest, marine (smolt-to-adult) survival and stock productivity data are unavailable for this DU because there is no coded-wire tag indicator stock.

Threats and limiting factors

For general threats and limiting factors applicable to all DUs, please refer to the Threats and Limiting Factors section in the introductory material. Further effort is required (for example, by eliciting expert knowledge) to determine a threat grade. This DU is considered a high priority for completion of an IUCN threats calculator.

Designatable Unit 8: Middle Fraser, Stream, Fall population (assessed November 2018)

DU short name

MFR+GStr/Stream/Fall

Joint Adaptive Zone (JAZ)

MFR+GStr

Life history

Stream

Run timing

Fall

The average generation time for this DU is 4.5 years. These fish exhibit stream-type life-history variants and fall run-timing.

To review methods pertaining to data reported within individual DU chapters, refer to the preliminary sections of this report.

Extent of occurrence and area of occupancy

This DU extends from the north side of Whitecap Creek (Lat. 50.75, Long. 122.47) along Seton Lake and Anderson Lake to Haylmore Creek in the south at Lat. 50.41, Long. 122.40. The DU's western-most extent is at McGillivray Creek (Lat. 50.61, Long. 122.62) and the eastern-most extent is at the Seton River's confluence with the Fraser River (Lat. 50.67, Long. 121.92). The DU's centroid occurs at Lat. 50.71, Long. 122.27, and its total area is 981.85 km².

As for all DUs considered in this report, the extent of occurrence includes spawning streams as well as the ocean range, and is therefore >20,000 km². The IAO is 63 km² based on a total known spawning run length of 32 km, or 0.32 percent of the known spawning length across all DUs.

Habitat trends

Land surrounding this DU's freshwater habitat is altered (5.0 percent), with agricultural / rural development comprising 0.1 percent of the DU area, and urban development comprising 0.9 percent. Road density in DU8 is 0.6km/km² with an average of 0.5 stream crossings per km of fish accessible streams (the average across all DUs is 1.33km/km² road density and 0.62 stream crossings per km of fish accessible streams). 4.5 percent of the DU's riparian habitat and 4.1 percent of its forest cover is disturbed. 3.0 percent of the DU's pine stands are affected by Mountain Pine Beetle. There is no mining development within the DU area. Seton Dam is within this DU and has resulted in degraded habitat below the dam (BC Hydro 2011a).

Abundance

No absolute abundance estimates are available for this DU, only relative abundance indices. All spawners originated from sample sites with low to moderate or unknown sampling effort/survey quality (Figure 54b). Twelve generational averages can be calculated from relative index spawner abundance time series data, all with less than 250 spawners (Figure 54c).

While the abundance data are indices, expert opinion indicates that the underestimate is not likely more than 50 percent. Of the years where sampling occurred, all mature individuals originated from a single stream (Portage Creek), that had low or unknown levels of enhancement (Figure 54a). No hatchery releases are on record.

Fluctuations and trends

The entire time series of data is within 3 generations. Based on these data, the number of mature individuals changed by an estimated -67 percent (Upper 95 percent CI = 13 percent, Lower 95 percent CI = -90 percent) with the probability of a 30 percent decline at 0.90 (Table 25, Figure 54 a,b).

Harvest, marine (smolt-to-adult) survival and stock productivity data are unavailable for this DU because there is no coded-wire tag indicator stock.

Threats and limiting factors

For general threats and limiting factors applicable to all DUs, please refer to the Threats and Limiting Factors section in the introductory material. Further effort is required (for example, by eliciting expert knowledge) to determine a threat grade. This DU is considered a high priority for completion of an IUCN threats calculator because escapement began declining in 2000-2001 and is currently very low (under 20 fish in 2016 and 2017) (Bailey pers. comm. 2018). Chinook Salmon spawning occurred in the Seton Portage, but habitat below Seton Dam has been degraded and is likely limiting (BC Hydro 2011a). This DU also contains an abandoned mine in the lower Nahatlatch River where waste rock was discarded into the Nahatlatch Canyon (Bailey pers. comm. 2018). Threats calculator spreadsheets are included with this report (see Appendix 1).

Designatable Unit 9: Middle Fraser, Stream, Spring (MFR+GStr) population (assessed November 2018)

DU short name

MFR+GStr/Stream/Spring

Joint Adaptive Zone (JAZ)

MFR+GStr

Life history

Stream

Run timing

Spring

The average generation time for this DU is 4.5 years. These fish exhibit stream-type life-history variants and spring run-timing.

To review methods pertaining to data reported within individual DU chapters, refer to the preliminary sections of this report.

Extent of occurrence and area of occupancy

Comprised of nine separate sections, this DU has one of the largest extents in this report. DU9 stretches from Driftwood River close to Bear Lake in the north (Lat. 56.17, Long. 126.97) to Stein River close to Skihist Mountain in the south at Lat. 50.12, Long. 122.01. From the west, the DU extends from Nadina River (Lat. 53.78, Long. 127.27) to Cariboo River close to Mount Lunn in the east (Lat. 53.07, Long. 120.43). The DU's centroid occurs at Lat. 52.72, Long. 123.09 and its total area is 47965.10 km².

As for all DUs considered in this report, the extent of occurrence includes spawning streams as well as the ocean range, and is therefore >20,000 km². The IAO is 4490 km² based on a total known spawning run length of 2245 km, or 22.32 percent of the known spawning length across all DUs.

Habitat trends

Land surrounding this DU's freshwater habitat is altered (16.1 percent), with urban development comprising 0.4 percent of the DU area, agricultural / rural development comprising 2.6 percent and mining development covering 0.1 percent. Road density in DU9 is 1.2 km/km² with an average of 0.5 stream crossings per km of fish accessible streams (the average across all DUs is 1.33 km/km² road density and 0.62 stream crossings per km of fish accessible streams). 13.5 percent of the riparian habitat and 13.0 percent of the forest cover is disturbed. 24.6 percent of the DU's pine stands are affected by Mountain Pine Beetle.

Chinook Salmon in the Bridge River are restricted to the lower river because of hydroelectric facilities. Prior to the installation of the Mission Dam at the outlet of Carpenter Lake, Chinook Salmon were present in the middle Bridge River and the tributaries Ferguson and Tyaughton creeks, where they were estimated at between 1 to 300 spawners, and 300 and 2,000 spawners respectively (BC Hydro 2011a). Spawning is now limited to areas downstream of the Terzaghi Dam (Komori 1997). Spawner abundance decreased in Yalakom River but increased in Bridge River when comparing the periods 1969-1980 to 1981-1992: the average number of spawners went from 136 to 23 in Yalakom River, and 125 to 529 in Bridge River (Komori 1997).

Abundance

For most years, no absolute abundance estimates are available for this DU, only relative abundance indices. Seventeen generational averages can be generated from relative index time series estimates, eight with 5,000 - 10,000 spawners and nine with less than 5,000 spawners (Figure 57c).

Most spawners originated from sample sites with moderate sampling effort/survey quality. Exceptions occurred in 2000 and 2015, when a small percentage of spawners came from high data quality sample sites (that is, absolute abundance estimates) (Figure 57b). Fourteen sites provided data for seventeen generational averages of absolute abundance, one site with generational averages of 2,500 to 5,000 spawners, another with 1,000 to 2,500 spawners, seven with 250 to 1,000 spawners, and five with less than 250 spawners (Figure 57d).

Of the years where sampling occurred, mature individuals all originated from streams with low or unknown levels of enhancement (Figure 57a). However, hatchery releases did occur within the DU from 1980 to 2000, peaking at ~1,200,000 fish in 1986. From the mid-1990s to 2001, a very small number of releases occurred (Figure 57e). Three releases are reported outside the DU prior to 2000. No hatchery releases are reported after 2001.

Fluctuations and trends

Based on the last three generations of data, the number of mature individuals changed by an estimated -28 percent (Upper 95 percent CI = 97 percent, Lower 95 percent CI = -73 percent) with the probability of a 30 percent decline at 0.48 (Table 26, Figure 58a,b). Using the entire time series, the number of mature individuals changed over the last three generations by an estimated ‑49 percent (Upper 95 percent CI = -9 percent, Lower 95 percent CI = -72 percent) with the probability of a 30 percent decline at 0.87 (Figure 58c).

Harvest, marine (smolt-to-adult) survival and stock productivity data are unavailable for this DU because there is no coded-wire tag indicator stock.

Threats and limiting factors

For general threats and limiting factors applicable to all DUs, please refer to the Threats and Limiting Factors section in the introductory material. Chinook Salmon experts who participated in the IUCN threats calculator workshop in February 2017 concluded that this DU should be assigned a threat impact of High - Medium (B/C). The most important threats specific to this DU are from ecosystem modifications. Irrigation diking and ditching in the Lower Fraser Basin contributes to a loss of backwater and off-channel habitat. These practices are increasingly expanding upstream along the Fraser River (Bailey pers. comm. 2018). A loss of rearing and overwintering habitat is also occurring due to conversion of agricultural land use to residential/commercial land use. The DU is also impacted by snowpack and hydrologic regime changes. Placer and hard rock mining, evidence of acid mine drainage, and contaminant leaching exists at several sites in the Cottonwood River (Bailey pers. comm. 2018). Often the aquatic pollution that leaches from these sites is evident by the yellow ochre algae on the river bottom. Acid mine drainage is a serious threat with the potential for long-term devastating impacts to the aquatic community and reduced productive capacity of these rivers. Placer mining has also occurred in the Bridge River.

Other less critical threats include impacts from livestock and farm equipment entering stream habitat, dams and water management, invasive species, droughts, temperature extremes and harvest rates. For this DU, brood-over-brood increases in spawners were generally seen from 2012-2015, but there was high ocean mortality. In addition to resident killer whales, seals and Sea Lions are significant predators.

In 2005, the harvest rate for this DU was 60 percent. Attempts to reduce this rate to 30 percent have not been fully successful – a range of 20-40 percent is probably closer to actual.

Threats calculator spreadsheets are included with this report (see Appendix 1).

Designatable Unit 10: Middle Fraser, Stream, Summer population (assessed November 2018)

DU short name

MFR+GStr/Stream/Summer

Joint Adaptive Zone (JAZ)

MFR+GStr

Life history

Stream

Run timing

Summer

The average generation time for this DU is 4.5 years. These fish exhibit stream-type life-history variants and summer run-timing.

To review methods pertaining to data reported within individual DU chapters, refer to the preliminary sections of this report.

Extent of occurrence and area of occupancy

This DU consists of five geographically separated sections spanning from Middle River close to Nesabut Mountain in the north (Lat. 55.23, Long. 125.58) to Elkin Creek in the south (Lat. 51.39, Long. 123.51). The DU's western-most extent occurs at Stellako River close to Mount Parrott at Lat. 54.12, Long. 126.71 and the eastern-most point is at Niagara Creek close to Mount Sir Wilfrid Laurier (Lat. 52.88, Long. 120.16). The DU's centroid occurs at Lat. 53.50, Long. 123.72, and its total area is 22072.99 km².

As for all DUs considered in this report, the extent of occurrence includes spawning streams as well as the ocean range, and is therefore >20,000 km². The IAO is 2616km² based on a total known spawning run length of 1308km, or 13 percent of the known spawning length across all DUs.

Habitat trends

Land surrounding this DU's freshwater habitat is altered (11.6 percent), with urban development comprising 0.9 percent of the DU area, agricultural / rural development comprising 2.0 percent and mining development comprising 0.1 percent. Road density in DU10 is 1.0km/km² with an average of 0.32 stream crossings per km of fish accessible streams (the average across all DUs is 1.33km/km² road density and 0.62 stream crossings per km of fish accessible streams). 11.4 percent of the riparian habitat and 8.5 percent of the forest cover is disturbed. 21.0 percent of the DU's pine stands are affected by Mountain Pine Beetle.

Abundance

For most years no absolute abundance estimates are available for this DU, only relative abundance indices. Thirteen generational averages can be generated from relative index spawner time series data, all indicating abundances of 10,000 or more fish (Figure 60c). Most spawners originate from census sites with moderate sampling effort/survey quality. An exception occurred in 2004 when ~20 percent of spawners came from a site with high data quality (that is, absolute abundance estimates) (Figure 60b). Six sites provide sufficient absolute abundance data to generate thirteen generational averages, one with 10,000 or more spawners, another with 5,000 and 10,000 spawners, one with 2,500 and 5,000 spawners, one with 1,000 and 2,500 spawners and two with less than 250 spawners (Figure 60d).

Of the years where sampling occurred, mature individuals all originated from streams with low or unknown levels of enhancement (Figure 60a). However, hatchery releases did occur from 1980 to 2013, peaking at about 2,200,000 fish then declining to a very small number of releases after 2000 (Figure 60e).

Fluctuations and trends

Based on the last three generations of data, the number of mature individuals changed by an estimated -38 percent (Upper 95 percent CI = 28 percent, Lower 95 percent CI = -70 percent) with the probability of a 30 percent decline at 0.64 (Table 27, Figure 61a,b). Using the entire time series of data (one additional year), the number of mature individuals changed over the last three generations by an estimated -29 percent (Upper 95 percent CI = 39 percent, Lower 95 percent CI = -63 percent) with the probability of a 30 percent decline at 0.48 (Figure 61c).

Harvest, marine (smolt-to-adult) survival and stock productivity data are unavailable for this DU because there is no coded-wire tag indicator stock.

Threats and limiting factors

For general threats and limiting factors applicable to all DUs, please refer to the Threats and Limiting Factors section in the introductory material. Further effort is required (for example, by eliciting expert knowledge) to determine a threat grade for this DU. Chinook Salmon experts who participated in the IUCN threats calculator workshop in February 2017 recommended using the DU17 threats calculator as a proxy for DU10 (see Table 18), but DU17 was not completed at the workshop.

Expert knowledge indicates placer and hard rock mining, acid mine drainage, and contaminant leaching occurs at several locations in the Quesnel River and Cariboo River (Bailey pers. comm. 2018). Often the aquatic pollution that leaches from these sites is evident by the yellow ochre algae on the river bottom. Acid mine drainage has potential for long-term devastating impacts to the aquatic community and reduced productive capacity of these rivers. The 2014 Mount Polley mining disaster occurred in this DU and involved a breach of the copper/gold mine's tailings pond, discharging toxic mud and water into Polley Lake. The Kenney dam, which is outside of the southernmost extent of the DU (approximate Lat. 53.58, Long. 124.95), may affect temperature and flow rates in the Nechako River, thereby changing the migration timing of Chinook Salmon smolts (Sykes et al. 2009).

Threats calculator spreadsheet templates are included with this report (see Appendix 1).

Designatable Unit 11: Upper Fraser, Stream, Spring population (assessed November 2018

DU short name

UFR/Stream/Spring

Joint Adaptive Zone (JAZ)

UFR

Life history

Stream

Run timing

Spring

The average generation time for this DU is 4.5 years. These fish exhibit stream-type life-history variants and spring run-timing.

To review methods pertaining to data reported within individual DU chapters, refer to the preliminary sections of this report.

Extent of occurrence and area of occupancy

This DU extends from Salmon River around Mount MacKinnon in the north (Lat. 54.62, Long. 123.69) to Raush River at Mount Sir Wilfrid Laurier in the south (Lat. 52.69, Long. 119.73). The eastern-most extent occurs at Holmes River along Mount Robson at Lat. 53.36, Long. 119.41. The western-most extent also occurs in the north near Salmon River. Further south, the DU boundary extends west near Mount Burdett at Lat. 52.98, Long. 121.51. The DU's centroid is at Lat. 53.67, Long. 120.91, and its total area is 24431.59km².

As for all DUs considered in this report, the extent of occurrence includes spawning streams as well as the ocean range, and is therefore >20,000 km². The IAO is 4065 km² based on a total known spawning run length of 2033 km, or 20.21 percent of the known spawning length across all DUs.

Habitat trends

Land surrounding this DU's freshwater habitat is altered (17.5 percent), with urban development comprising 0.09 percent of the DU area, agricultural / rural development comprising 0.7 percent, and mining development comprising 0.01 percent. Road density in DU11 is 0.9 km/km² with an average of 0.5 stream crossings per km of fish accessible streams (the average across all DUs is 1.33 km/km² road density and 0.62 stream crossings per km of fish accessible streams). 15.5 percent of the riparian habitat and 16.6 percent of the forest cover is disturbed. 5.5 percent of the DU's pine stands are affected by Mountain Pine Beetle.

Abundance

Almost all data originate from sample sites with relative abundance indices of moderate sampling effort/survey quality. A small proportion of sample sites provided absolute abundance estimates between 1999 and 2007 (Figure 63b). Seventeen generational averages can be generated from spawner abundance time series data, all indicating abundances of 10,000 or more spawners (Figure 63c). Absolute abundance estimates were obtained from twenty-eight sites, over half of which had less than 250 spawners. One site had 5,000-10,000, another had 2,500-5,000, two sites had 1,000-2,500, and nine sites had 250-1,000 spawners.

Of the years where sampling occurred, almost all observed spawners originated from streams with low or unknown levels of enhancement (Figure 63a). A relatively high level of hatchery releases occurred in the 1980s, reaching a maximum of ~1,000,000 fish in 1984. After 1989, hatchery releases declined to ~50,000, before halting completely by 2005 (Figure 63e).

Fluctuations and Trends

Based on the last three generations of data, the number of mature individuals changed by an estimated -49 percent (Upper 95 percent CI = 15 percent, Lower 95 percent CI = -77 percent) with the probability of a 30 percent decline at 0.79 (Table 28, Figure 64a,b). Using the entire time series of data, the number of mature individuals changed over the last three generations by an estimated -43 percent (Upper 95 percent CI = -8 percent, Lower 95 percent CI = -64 percent) with the probability of a 30 percent decline at 0.81.

The total exploitation rate increased from a low of around 0.1 in 1986 to a high of 0.8 in 1996, but began to decline from 2000-2002 (Figure 64d). The last CWT data available in nuSEDS (shown here) are from brood year 2002 and indicate an exploitation rate of 0.4. More recently, in-river harvest was estimated using a run reconstruction model and was found to fluctuate between 10-20 percent (English et al. 2007). Marine (smolt-to-adult) survival averaged a rate of ~0.01 from 1986 to 2002, and fluctuated little in that time (Figure 64e). Marine survival data are not available past 2002. Stock productivity data are not available for this DU.

Threats and limiting factors

For general threats and limiting factors applicable to all DUs, please refer to the Threats and Limiting Factors section in the introductory material. Chinook Salmon experts who participated in the IUCN threats calculator Workshop in February 2017 concluded that this DU should be assigned a threat impact of High - Medium (B/C). Because females in fall actively seek a mix of groundwater and surface water when selecting redd sites, the most important threats specific to this DU are ecosystem modifications due to climate change, cyclical marine climate events (El Niño) and resulting shifts in groundwater availability caused by changes in the volume and timing of snowmelt. Another round of ocean survival impacts as in 2003 and 2007 could terminate groups of Chinook Salmon within the DU. Historic placer mining in the Bowron and Willow River systems also resulted in significant habitat alteration via large amounts of fine sediment washed into the river (Bailey pers. comm. 2018). Sedimentation can reduce egg-to-fry survival and adversely affect the aquatic insect community for rearing Chinook Salmon.

There has been limited success at maintaining a harvest target of 30 percent for this DU, with the most recent brood year at 40 percent. Chinook Salmon encounter nets all the way up the Fraser River and are exposed to constant fishing pressure exacerbated by slow migration speed from the river mouth to spawning grounds.

Other impacts include invasive species (esp. spiny rayed fish), avalanches/landslides, droughts, and temperature extremes.

Threats calculator spreadsheets are included with this report (see Appendix 1).

Designatable Unit 12: South Thompson, Ocean, Summer population (assessed November 2018)

DU short name

ST+GStr/Ocean/Summer

Joint Adaptive Zone (JAZ)

STh+GStr

Life history

Ocean

Run timing

Summer

The average generation time for this DU is 3.8 years. These fish exhibit ocean-type life-history variants and summer run-timing.

To review methods pertaining to data reported within individual DU chapters, refer to the preliminary sections of this report.

Extent of occurrence and area of occupancy

This DU extends west to east from Battle Creek around Mount Fehr (Lat. 50.84, Long. 121.20) to Spectrum Creek around Mount Odin in the southeast portion of the DU (Lat. 50.18, Long. 118.30). The northern-most extent occurs near Seymour Arm at the north end of Shuswap Lake (Lat. 51.25, Long. 118.99) and the southern-most extent occurs at Ferry Creek (Lat. 50.05, Long. 118.77). The DU's centroid is located at Lat. 50.67, Long. 119.34, and its total area is 10330.45 km².

As for all DUs considered in this report, the extent of occurrence includes spawning streams as well as the ocean range, and is therefore >20,000 km². The IAO is 1125 km² based on a total known spawning run length of 563 km, or 5.60 percent of the known spawning length across all DUs.

This DU is a combination of two Wild Salmon Policy Conservation Units: CK-13 and CK-15.

Habitat trends

Land surrounding this DU's freshwater habitat is altered (20.3 percent), with agricultural / rural development comprising 6.4 percent, and urban development comprising 0.9 percent of the DU area. Road density in DU12 is 1.5km/km² with an average of 0.7 stream crossings per km of fish accessible streams (the average across all DUs is 1.33km/km² road density and 0.62 stream crossings per km of fish accessible streams). 20.5 percent of the DU's riparian habitat and 13.0 percent of the forest cover is disturbed. 2.5 percent of the pine stands are affected by Mountain Pine Beetle. No mining development is reported within the DU by Porter et al. (2013). However, see comments in the Threats and Limiting Factors section below regarding potential risks associated with the Highland Valley Cooper and New Afton mines.

The South Thompson River and Little River were both dredged for shipping traffic. Spawning gravel was removed from the thalweg and or placed on shore or piled in mid-channel berms, which exceed the river level creating islands during spawning season (Bailey pers. comm. 2018). This activity reduced the spawning habitat and productive capacity of the DU.

Abundance

Most spawner data originated from sample sites with moderate sampling effort/survey quality except in the CK-15 portion of the DU, where from 2005 onward most spawner data originated from sites with high sampling effort/survey quality (Figure 67b). Sixteen generational averages can be calculated from spawner time series data available from CK-13 and thirty from CK-15. In both units, generational averages indicate 10,000 or more spawners (Figure 66c and Figure 67c). The average proportion of spawners contributed by each CK was 0.673 (CK-13), and 0.327 (CK-15). Six sites with absolute spawner data are identified (CK-13 and CK-15 combined). The four sites in CK-13 and one site in CK-15 are estimated at an average of 10,000 or more spawners. The remaining site (Shuswap River-Middle) is estimated at 2,500-5,000 spawners.

Of the years where sampling occurred, all spawners in CK-13 and most spawners in CK-15 originated from streams that had low or unknown levels of enhancement (Figure 66a and Figure 67a). Depending on the year, approximately 10-30 percent of spawners in CK-15 were from enhanced streams (Figure 67a). Hatchery releases within CK-15 started in 1980 and peaked at over 2 million fish before leveling off over the last fifteen years at around ~750,000 releases annually (Figure 67e). No hatchery releases are reported in CK-13.

Fluctuations and trends

Based on the last three generations of data, the number of mature individuals changed by an estimated 26 percent (Upper 95 percent CI = 195 percent, Lower 95 percent CI = -45 percent) with the probability of a 30 percent decline at 0.07 (Table 29, Figure 68a,b). Using the entire time series of data, the number of mature individuals changed over the last three generations by an estimated 64 percent (Upper 95 percent CI = 95 percent, Lower 95 percent CI = 38 percent) with zero probability of a 30 percent decline (Table 29, Figure 68a,c).

While coded-wire tag indicator stocks do exist, harvest, marine (smolt-to-adult) survival and stock productivity data are currently unavailable for this DU.

Threats and limiting factors

For general threats and limiting factors applicable to all DUs, please refer to the Threats and Limiting Factors section in the introductory material. Further effort is required (for example, by eliciting expert knowledge) to determine a threat grade. This DU is considered a lower priority for completion of an IUCN threats calculator.

While Porter et al. (2013) report no mining development within the DU, the Highland Valley Cooper and New Afton mines have tailings ponds that, in the event of a failure, could result in toxic runoff entering the DU in the Thompson River (Bailey pers. comm. 2018).

Designatable Unit 13: South Thompson, Stream, Summer 1.3 population (not yet assessed)

Figures and tables to appear in Part Two:

Figure 69. Map of DU13 – South Thompson Stream Summer 1.3.

Figure 70. DU13 – Abundance, enhancement, and hatchery releases.

Table 30. Summary of estimated rate of change (±95 percent credible interval) in spawner abundance and probability of decline over the last three generations (>30 percent, >50 percent, >70 percent). Rates of change over the last three generations are provided based on analysis of the last three generations of data as well as the entire time series.

Figure 71. DU13 – Trends in spawner abundance, exploitation rate, and marine (smolt-to-adult) survival.

Designatable Unit 14: South Thompson, Stream, Summer 1.2 population (assessed November 2018)

DU short name

STh+GStr/Stream/Summer

Joint Adaptive Zone (JAZ)

STh+GStr

Life history

Stream

Run timing

Summer

Unlike DU13, the average generation time for this DU at 3 years is atypical of Chinook Salmon (4.1yrs using Nicola River Spring as a proxy as stated in Table 17), like DU13, these fish exhibit stream-type life-history variants and summer run-timing – the title suffixes 1.2 and 1.3 are used to differentiate between these life-history strategies.

To review methods pertaining to data reported within individual DU chapters, refer to the preliminary sections of this report.

Extent of occurrence and area of occupancy

This DU extends from Vance Creek in the northwest near Silver Star Provincial Park (Lat. 50.33, Long. 119.39) to Duteau Creek around Buck Mountain (Lat. 50.02, Long. 118.87). The DU's centroid is at Lat. 51.45, Long. 120.08, and its total area is 794.19 km².

As for all DUs considered in this report, the extent of occurrence includes spawning streams as well as the ocean range, and is therefore >20,000 km². The IAO is 70 km² based on a total known spawning run length of 35 km, or 0.35 percent of the known spawning length across all DUs.

Habitat trends

Land surrounding this DU's freshwater habitat is altered (24.0 percent), with agricultural / rural development comprising 8.0 percent and urban development 0.9 percent of the DU area. Road density in DU14 is 1.7 km/km² with an average of 0.7 stream crossings per km of fish accessible streams (the average across all DUs is 1.33 km/km² road density and 0.62 stream crossings per km of fish accessible streams). 20.4 percent of the DU's riparian habitat and 15.7 percent of its forest cover is disturbed. 5.3 percent of pine stands in the DU are affected by Mountain Pine Beetle. No mining development occurs within the DU boundaries.

Abundance

Most spawners originate from sample sites with moderate sampling effort/survey quality (Figure 73b). Fifteen generational averages can be calculated from available abundance time series data (Figure 73c), all but two with between 250 and 1,000 spawners. The remaining two generational averages indicate less than 250 spawners. Absolute abundance data are from two sites, each averaging less than 250 spawners (Figure 73d).

Of the years where sampling occurred, mature individuals all originate from streams with low or unknown levels of enhancement (Figure 73a). No hatchery releases are on record for this DU.

Fluctuations and trends

Based on the last three generations of data, the number of mature individuals changed by an estimated -47 percent (Upper 95 percent CI = 705 percent, Lower 95 percent CI = -96 percent) with the probability of a 30 percent decline at 0.59 (Table 31, Figure 74a,b). Using the entire time series of data, the number of mature individuals changed over the last three generations by an estimated -76 percent (Upper 95 percent CI = -31 percent, Lower 95 percent CI = -92 percent) with the probability of a 30 percent decline at 0.98 (Figure 74a,c).

Harvest, marine (smolt-to-adult) survival and stock productivity data are unavailable for this DU because there is no coded-wire tag indicator stock.

Threats and limiting factors

For general threats and limiting factors applicable to all DUs, please refer to the Threats and Limiting Factors section in the introductory material. Chinook Salmon experts who participated in the IUCN threats calculator workshop in February 2017 recommended using the DU15 threats calculator as a proxy for this DU (see Table 18) with the main difference being that, as for DU13, juveniles in DU14 stay in freshwater for one year and utilize smaller rivers. These characteristics make the fish more vulnerable than DU15 Chinook Salmon to water management issues and increased development. In the Bessette and Duteau rivers, for example, Chinook Salmon contend with dewatering events, agricultural runoff and rising stream temperatures (Bailey pers. comm. 2018). Considerable agriculture occurs in the DU with cattle ranching and farming adversely affecting the amount and quality of the riparian habitat. Dams occur in the headwaters of this system, diverting water out of the drainage and affecting mean annual discharge and seasonal low discharge. Based on these points and DU15 results, participants concluded that DU14 should be assigned a threat impact of High-Medium (B/C). Because females in fall actively seek a mix of groundwater and surface water when selecting redd sites, the most important threats in this DU are ecosystem modifications due to climate change, cyclical marine climate events (El Niño) and resulting shifts in groundwater availability caused by changes in the volume and timing of snowmelt. Another round of ocean survival impacts as in 2003 and 2007 could terminate groups of Chinook Salmon within the DU. Other less critical impacts include invasive species (esp. spiny rayed fish), avalanches/landslides, droughts, and temperature extremes.

Threat calculator results for this population are based on those from DU15.

Designatable Unit 15: Lower Thompson, Stream, Spring population (not yet assessed)

Figures and tables to appear in Part Two:

Figure 75. Map of DU15 – Lower Thompson Stream Spring.

Figure 76. DU15 – Abundance, enhancement, and hatchery releases.

Table 32. Summary of estimated rate of change (±95 percent credible interval) in spawner abundance and probability of decline over the last three generations (>30 percent, >50 percent, >70 percent). Rates of change over the last three generations are provided based on analysis of the last three generations of data as well as the entire time series.

Figure 77. DU15 – Trends in spawner abundance, exploitation rate, and marine (smolt-to-adult) survival.

Designatable Unit 16: North Thompson, Stream, Spring population (assessed November 2018)

DU short name

NTh+GStr/Stream/Spring

Joint Adaptive Zone (JAZ)

NTh+GStr

Life history

Stream

Run timing

Spring

The average generation time for this DU is 4.5 years. These fish exhibit stream-type life-history variants and spring run-timing.

To review methods pertaining to data reported within individual DU chapters, refer to the preliminary sections of this report.

Extent of occurrence and area of occupancy

This DU extends from Mt. Sir Allan McNab, Mt. Charlotte, and Albreda Mountain in the north, to Dunn Lake and Dunn Creek Protected Area in the south. The westernmost extent is located where Dunn Lake flows into the North Thompson River and the easternmost extent occurs at Mud Creek near Hallam Peak (N: Lat. 52.67, Long. 119.11; S: Lat. 51.38, Long. 120.10; W: Lat. 51.46, Long. 120.17; E: Lat. 52.18, Long. 118.80). The centroid of the DU area is at Lat. 51.88, Long. 119.51, and its total area is 4105.59 km².

As for all DUs considered in this report, the extent of occurrence includes spawning streams as well as the ocean range, and is therefore >20,000 km². The IAO is 291 km² based on a total known spawning run length of 146km, or 1.45 percent of the known spawning length across all DUs.

Habitat trends

Land surrounding this DU's freshwater habitat is altered (17.8 percent), with agricultural / rural development comprising 0.4 percent and the urban development 0.2 percent of the DU area. Road density in DU16 is 1.2km/km² with an average of 0.6 stream crossings per km of fish accessible streams (the average across all DUs is 1.33 km/km² road density and 0.62 stream crossings per km of fish accessible streams). 15.4 percent of the DU's riparian habitat is disturbed and 17.2 percent of its forest cover is disturbed. 3.3 percent of pine stands in the DU are affected by Mountain Pine Beetle. No mining development occurs within the DU area.

Abundance

No absolute abundance estimates are available for this DU, only relative abundance indices. Almost all spawner data originate from sample sites with moderate sampling effort/survey quality (Figure 79b). Thirteen generational averages can be calculated from relative index spawner abundance time series estimates, with six years having generational averages between 250 and 1,000 spawners and 7 with less than 250 spawners (Figure 79c). Data originate from two sites, each with generational averages of less than 250 spawners.

Of the years where sampling occurred, mature individuals all originated from streams that had low or unknown levels of enhancement (Figure 79a). Only two hatchery releases in the 1980s are reported for this DU (Figure 79e). Finn Creek spawners were the brood source for these fish. Juveniles were released into Finn Creek as 0+ smolts during four separate releases in 1985, all with a CWT. An additional 0+ smolt release occurred from the same brood source in 1989 but was not tagged or clipped (G. Brown, pers. comm.).

Fluctuations and trends

Based on the last three generations of data, the number of mature individuals changed by an estimated -91 percent (Upper 95 percent CI = -81 percent, Lower 95 percent CI = -95 percent) with the probability of a 30 percent decline at 100 percent (Table 33, Figure 80a,b). Using the entire time series of data, the number of mature individuals changed over the last three generations by an estimated -88 percent (Upper 95 percent CI = -76 percent, Lower 95 percent CI = -94 percent) also with the probability of a 30 percent decline at 100 percent (Table 33, Figure 80a,c).

Harvest, marine (smolt-to-adult) survival and stock productivity data are unavailable for this DU because there is no coded-wire tag indicator stock.

Threats and limiting factors

For general threats and limiting factors applicable to all DUs, please refer to the Threats and Limiting Factors section in the introductory material. Chinook Salmon experts who participated in the IUCN threats calculator workshop in February 2017 recommended using the DU11 threats calculator as a proxy for this DU (see Table 18). Based on DU11 results DU16 should be assigned a threat impact of High - Medium (B/C). Because females in fall actively seek a mix of groundwater and surface water when selecting redd sites, the most important threats specific to this DU are ecosystem modifications due to climate change, cyclical marine climate events (El Niño) and resulting shifts in groundwater availability caused by changes in the volume and timing of snowmelt. Another round of ocean survival impacts as in 2003 and 2007 could terminate groups of Chinook Salmon within the DU.

Other impacts include invasive species (for example, perch), avalanches/landslides, droughts, and temperature extremes.

Designatable Unit 17: North Thompson, Stream, Summer population (assessed November 2018)

DU short name

NTh+Gstr/Stream/Summer

Joint Adaptive Zone (JAZ)

NTh+GStr

Life history

Stream

Run timing

Summer

The average generation time for this DU is 4.5 years. These fish exhibit stream-type life-history variants and summer run-timing.

To review methods pertaining to data reported within individual DU chapters, refer to the preliminary sections of this report.

Extent of occurrence and area of occupancy

This DU includes the drainage of the Clearwater River and the southern portion of the North Thompson River. The area extends southwest-ward from Murtle River around Kilpill Mountain to the North Thompson River's confluence with the Thompson near at Kamloops, BC. The westernmost extent is located near the west end of Mahood Lake and the easternmost extent is located at Bendelin Creek around Saskum Mountain (N: Lat. 52.14, Long. 119.90; S: Lat. 50.68, Long. 120.34; W: Lat. 51.85, Long. 120.53; E: Lat. 51.37, Long. 119.50). The DU's centroid is at Lat. 51.43, Long. 120.15, and its total area is 6168.43 km².

As for all DUs considered in this report, the extent of occurrence includes spawning streams as well as the ocean range, and is therefore >20,000 km². The IAO is 714km² based on a total known spawning run length of 357 km, or 3.55 percent of the known spawning length across all DUs.

Habitat trends

Land surrounding this DU's freshwater habitat is altered (15.2 percent), with urban development comprising 0.7 percent and agricultural / rural development 3.3 percent of the DU area. Road density in DU17 is 1.3 km/km², with an average of 0.7 stream crossings per km of fish accessible streams (the average across all DUs is 1.33 km/km² road density and 0.62 stream crossings per km of fish accessible streams). 12.8 percent of the DU's riparian habitat and 11.2 percent of its forest cover is disturbed. 6.8 percent of pine stands in the DU are affected by Mountain Pine Beetle. No mining development occurs in the DU area.

Abundance

No absolute abundance estimates are available for this DU, only relative abundance indices. Most spawners originate from sample sites with moderate sampling effort/survey quality (Figure 82b). Fifteen generational averages can be calculated from available relative index spawner abundance time series data, six with generational averages of 5,000-10,000 fish, seven with 2,500-5,000 fish and two with less than 2,500 fish (Figure 82c). Spawner abundance estimates originate from five sites (seven spawning sites are documented), one with 2,500-5,000 fish and the remaining four with less than 250 fish (Figure 82d). All five sites are showing declines.

Of the years where sampling occurred, mature individuals all originated from streams that had low to unknown levels of enhancement (Figure 82a). Hatchery releases occurred from 1984 to 1992, reaching a maximum of ~2,000,000 in 1988 before dropping to ~0 in 1992 (Figure 82e). Spawners from Clearwater River, Raft River and North Thompson River have been used as brood stock and 95 percent of all releases were 0+ smolts. The remaining 5 percent were split among fed fry and 1+ smolt releases (G. Brown, pers. comm.).

Fluctuations and trends

Based on the last three generations of data, the number of mature individuals changed by an estimated -62 percent (Upper 95 percent CI = -10 percent, Lower 95 percent CI = -84 percent), with the probability of a 30 percent decline at 0.93 (Table 34,Figure 83a,b). Using the entire time series of data, the number of mature individuals changed over the last three generations by an estimated -64 percent (Upper 95 percent CI = -33 percent, Lower 95 percent CI = -80 percent), with the probability of a 30 percent decline at 0.98 (Table 34,Figure 83a,c).

Harvest, marine (smolt-to-adult) survival and stock productivity data are unavailable for this DU because there is no coded-wire tag indicator stock.

Threats and limiting factors

For general threats and limiting factors applicable to all DUs, please refer to the Threats and Limiting Factors section in the introductory material. Further effort is required (for example, by eliciting expert knowledge) to determine an IUCN threats calculator threat grade.

Designatable Unit 18: South Coast - Georgia Strait, Ocean, Fall population (not yet assessed)

Figures and tables to appear in Part Two:

Figure 84. Map of DU18 – South Coast - Georgia Strait Ocean Fall.

Figure 85. DU18 – Abundance, enhancement, and hatchery releases.

Designatable Unit 19: East Vancouver Island, Stream, Spring population (assessed November 2018)

DU short name

EVI+GStr/Stream/Spring

Joint Adaptive Zone (JAZ)

EVI+GStr

Life history

Stream

Run timing

Spring

The average generation time for this DU is 3.5 years. These fish exhibit stream-type life-history variants and spring run-timing.

To review methods pertaining to data reported within individual DU chapters, refer to the preliminary sections of this report.

Extent of occurrence and area of occupancy

This DU extends eastward from Sadie Creek at Mount Moriarty to Nanaimo River around Mount Hooker. The northernmost extent occurs at Rush Creek around Okay Mountain, and the southernmost extent occurs at Green Creek close to Mount Buttle (N: Lat. 49.16, Long. 124.27; S: Lat. 48.96, Long. 124.33; W: Lat.49.12, Long. 124.52; E: Lat. 49.07, Long. 124.20). The DU's centroid is at Lat. 49.09, Long. 124.23, and its total area is 245.33 km².

As for all DUs considered in this report, the extent of occurrence includes spawning streams as well as the ocean range, and is therefore >20,000 km². The IAO is 41 km² based on a total known spawning run length of 21 km, or 0.21 percent of the known spawning length across all DUs.

Habitat trends

Land surrounding this DU's freshwater habitat is altered (23.6 percent), with urban development comprising 3.6 percent, agricultural / rural development 2.7 percent and mining development 0.3 percent of the DU area. Road density in DU19 is 2.5 km/km² with an average of 0.9 stream crossings per km of fish accessible streams (the average across all DUs is 1.33 km/km² road density and 0.62 stream crossings per km of fish accessible streams). 20.9 percent of the DU's riparian habitat and 17.0 percent of its forest cover disturbed. This DU is not affected by Mountain Pine Beetle.

Abundance

This DU lacks consistent abundance, enhancement or hatchery release data. However, limited abundance data indicate that from 1987 to 2007, the maximum number of fish seen in any year was 25. In 1979, 166 fish were recorded, the highest value. More recently, in 2012 and 2013 only 2 and 5 fish were seen, respectively. While the recent survey information is an underestimate by an unknown amount, the number of mature fish is still likely less than the threshold of 250.

Fluctuations and trends

Trends in abundance, harvest, marine (smolt-to-adult) survival and stock productivity data are unavailable.

Threats and limiting factors

For general threats and limiting factors applicable to all DUs, please refer to the Threats and Limiting Factors section in the introductory material. Further effort is required (for example, by eliciting expert knowledge) to determine an IUCN threats calculator threat grade.

Designatable Unit 20: East Vancouver Island, Ocean, Summer population (not yet assessed)

Figures and tables to appear in Part Two:

Figure 87. Map of DU20 – East Vancouver Island Ocean Summer.

Figure 88. DU20 – Abundance, enhancement, and hatchery releases.

Table 35. Summary of estimated rate of change (±95 percent credible interval) in spawner abundance and probability of decline over the last three generations (>30 percent, >50 percent, >70 percent). Rates of change over the last three generations are provided based on analysis of the last three generations of data as well as the entire time series.

Figure 89. DU20 – Trends in spawner abundance, exploitation rate, and marine (smolt-to-adult) survival.

Designatable Unit 21: East Vancouver Island, Ocean, Fall population (not yet assessed)

Figures and tables to appear in Part Two:

Figure 90. Map of DU21 – East Vancouver Island Ocean Fall.

Figure 91. DU21 (CK-21) – Abundance, enhancement, and hatchery releases.

Figure 92. DU21 (CK-22) – Abundance, enhancement, and hatchery releases.

Figure 93. DU21 (CK-25) – Abundance, enhancement, and hatchery releases.

Figure 94. DU21 (CK-27) – Abundance, enhancement, and hatchery releases.

Table 36. Summary of estimated rate of change (±95 percent credible interval) in spawner abundance and probability of decline over the last three generations (>30 percent, >50 percent, >70 percent). Rates of change over the last three generations are provided based on analysis of the last three generations of data as well as the entire time series.

Figure 95. DU21 – Trends in spawner abundance, exploitation rate, and marine (smolt-to-adult) survival.

Figure 96. DU21 Stock productivity calculated as the total number of adults (spawners and catch) produced by spawners from a brood year (BY) divided by the number of spawners in the brood year. Productivity data are only available for CK-22. This figure is updated from Brown et al. 2013.

Designatable Unit 22: South Coast – Southern Fjords, Ocean, Fall (not yet assessed

Figures and tables to appear in Part Two:

Figure 97. Map of DU22 – South Coast – Southern Fjords Ocean Fall.

Figure 98. DU22 – Abundance, enhancement, and hatchery releases.

Table 37. Summary of estimated rate of change (±95 percent credible interval) in spawner abundance and probability of decline over the last three generations (>30 percent, >50 percent, >70 percent). Rates of change over the last three generations are provided based on analysis of the last three generations of data.

Figure 99. DU22 – Trends in spawner abundance, exploitation rate, and marine (smolt-to-adult) survival.

Designatable Unit 23: East Vancouver Island, Ocean, Fall (EVI + SFj) population (not yet assessed)

Figures and tables to appear in Part Two:

Figure 100. Map of DU23 – East Vancouver Island Ocean Fall (EVI + SFj).

Figure 101. DU23 – Abundance, enhancement, and hatchery releases.

Table 38. Summary of estimated rate of change (±95 percent credible interval) in spawner abundance and probability of decline over the last three generations (>30 percent, >50 percent, >70 percent). Rates of change over the last three generations are provided based on analysis of the last three generations of data as well as the entire time series.

Figure 102. DU23 – Trends in spawner abundance, exploitation rate, and marine (smolt-to-adult) survival.

Designatable Unit 24: West Vancouver Island, Ocean, Fall (South) population (not yet assessed)

Figures and tables to appear in Part Two:

Figure 103. Map of DU24 – West Vancouver Island Ocean Fall (South).

Figure 104. DU24 – Abundance, enhancement, and hatchery releases.

Table 39. Summary of estimated rate of change (±95 percent credible interval) in spawner abundance and probability of decline over the last three generations (>30 percent, >50 percent, >70 percent). Rates of change over the last three generations are provided based on analysis of the last three generations of data as well as the entire time series.

Figure 105. DU24 – Trends in spawner abundance, exploitation rate, and marine (smolt-to-adult) survival.

Figure 106. DU24 – Disaggregated ocean and terminal exploitation rates 1970-2015.

Designatable Unit 25: West Vancouver Island, Ocean, Fall (Nootka and Kyuquot) population (not yet assessed)

Figures and tables to appear in Part Two:

Figure 107. Map of DU25 – West Vancouver Island Ocean Fall (Nootka and Kyuquot).

Figure 108. DU25 – Abundance, enhancement, and hatchery releases.

Table 40. Summary of estimated rate of change (±95 percent credible interval) in spawner abundance and probability of decline over the last three generations (>30 percent, >50 percent, >70 percent). Rates of change over the last three generations are provided based on analysis of the last three generations of data as well as the entire time series.

Figure 109. DU25 – Trends in spawner abundance, exploitation rate, and marine (smolt-to-adult) survival.

Designatable Unit 26: West Vancouver Island, Ocean, Fall (WVI + WQCI) population (not yet assessed)

Figures and tables to appear in Part Two:

Figure 110. Map of DU26 – West Vancouver Island Ocean Fall (WVU + WQCI).

Figure 111. DU26 – Abundance, enhancement, and hatchery releases.

Table 41. Summary of estimated rate of change (±95 percent credible interval) in spawner abundance and probability of decline over the last three generations (>30 percent, >50 percent, >70 percent). Rates of change over the last three generations are provided based on analysis of the last three generations of data as well as the entire time series.

Figure 112. DU26 – Trends in spawner abundance, exploitation rate, and marine (smolt-to-adult) survival.

Designatable Unit 27: Southern Mainland, Ocean, Summer population (assessed November 2018)

DU short name

HK+SFj/Ocean/Summer

Joint Adaptive Zone (JAZ)

HK+SFj

Life history

Ocean

Run timing

Summer

The average generation time for this DU is 4.5 years. These fish exhibit ocean-type life-history variants and summer run-timing.

To review methods pertaining to data reported within individual DU chapters, refer to the preliminary sections of this report.

Extent of occurrence and area of occupancy

This DU contains the Homathko River drainage and extends south from Mosley Creek around West Branch Peaks to the Homathko River's outlet into Bute Inlet. The westernmost extent is located at Scar Creek close to Dauntless Mountain and the easternmost point occurs at Doran Creek close to Mount Queen Bess (N: Lat. 51.56, Long. 125.06; S: Lat. 50.89, Long. 124.93; W: Lat. 51.20, Long. 125.33; E: Lat. 51.20, Long. 124.46). The DUs centroid is at Lat. 50.93, Long. 124.86 and its total area is 2836.28 km².

As for all DUs considered in this report, the extent of occurrence includes spawning streams as well as the ocean range, and is therefore >20,000 km². The IAO is 154 km² based on a total known spawning run length of 77 km, or 0.77 percent of the known spawning length across all DUs.

Habitat trends

Land surrounding this DU's freshwater habitat is altered (5.8 percent), with agricultural / rural development comprising 1.4 percent of the DU area. Road density in DU27 is 0.4 km/km² with an average of 0.4 stream crossings per km of fish accessible streams (the average across all DUs is 1.33 km/km² road density and 0.62 stream crossings per km of fish accessible streams). 5.4 percent of the DU's riparian habitat and 4.4 percent of its forest cover is disturbed. 11 percent of the DU area is affected by Mountain Pine Beetle. No urban development or mining development occurs within the DU.

Abundance

This DU has little information pertaining to abundance. Chinook Salmon within this DU occur in a large glacially turbid system within this remote area. Recent relative indices of spawners was zero and 267 fish in 2010 and 2011, respectively. In the past (1960s and 1970s), surveys indicated thousands of fish, but the quality of the surveys was uncertain and the comparability of the estimates between the periods is unknown.

Fluctuations and trends

Trends in abundance, harvest, marine (smolt-to-adult) survival and stock productivity data are unavailable.

Threats and limiting factors

For general threats and limiting factors applicable to all DUs, please refer to the Threats and Limiting Factors section in the introductory material. Chinook Salmon experts who participated in the IUCN threats calculator workshop in February 2017 concluded that this DU should be assigned a threat impact of Low (D). Some risk exists from ecosystem modifications due to independent power producers (minimal) and from avalanches/landslides due to the steep terrain in this system. Threat Calculator results for this population are based on those from DU28. Many issues need to be further investigated. There are a number of 'Unknown' Threat Calculator scores that, if populated, could change the overall threat rating.

While harvest is pervasive and continuing, it is not considered a threat because its severity is not expected to change much over the next three generations of Chinook Salmon. Thus, any harvest impacts on current population levels would be negligible.

Designatable Unit 28: Southern Mainland, Stream, Summer population (assessed November 2018)

DU short name

HK+SFj/Stream/Summer

Joint Adaptive Zone (JAZ)

HK+SFj

Life history

Stream

Run timing

Summer

The average generation time for this DU is 4.5 years. These fish exhibit stream-type life-history variants and summer run-timing.

To review methods pertaining to data reported within individual DU chapters, refer to the preliminary sections of this report.

Extent of occurrence and area of occupancy

This DU extends southwestward from McClinchy Creek close to Charlotte Lake to the Klinaklini River's outlet into Knight Inlet (N: Lat. 52.24, Long. 125.17; S: Lat. 51.10, Long. 125.61). The easternmost extent is located at Klinaklini River close to Martin Mountain (Lat. 51.96, Long. 124.68), and the west end is located at West Klinaklini River close to Silverthrone Mountain (Lat. 51.42, Long. 126.16). The DU's centroid is at Lat. 51.27, Long 125.61 and its total area is 5,848.22 km².

As for all DUs considered in this report, the extent of occurrence includes spawning streams as well as the ocean range, and is therefore >20,000 km². The IAO is 447 km² based on a total known spawning run length of 224 km, or 2.23 percent of the known spawning length across all DUs.

Habitat trends

Land surrounding this DU's freshwater habitat is altered (5.4 percent), with urban development comprising 0.02 percent, and agricultural / rural development 0.6 percent of the DU area. Road density in DU28 is 0.3 km/km² with an average of 0.3 stream crossings per km of fish accessible streams (the average across all DUs is 1.33 km/km² road density and 0.62 stream crossings per km of fish accessible streams). 1.4 percent of the DU's riparian habitat and 4.7 percent of its forest cover is disturbed. 15.0 percent of pines stand are affected by Mountain Pine Beetle. No mining development within the DU.

Abundance

While historical estimates of abundance are available for this wildlife species, the methods have changed over time. The most recent estimate in 2003 was 13,365. No data exist over the past three generations. This DU is not considered enhanced, but one hatchery release of ~233,000 smolts did occur in 1985 (Figure 115e).

Fluctuations and trends

Trends in abundance, harvest, marine (smolt-to-adult) survival and stock productivity data are unavailable.

Threats and limiting factors

For general threats and limiting factors applicable to all DUs, please refer to the Threats and Limiting Factors section in the introductory material. Chinook Salmon experts who participated in the IUCN threats calculator Workshop in February 2017 concluded that this DU should be assigned a threat impact of Low (D). Some risk exists from ecosystem modifications due to independent power producers (minimal) and from avalanches/landslides due to the steep terrain in this system. Many issues need to be further investigated. There are a number of ‘Unknown' threat calculator scores that, if populated, could change the overall threat rating.

While harvest is pervasive and continuing, it is not considered a threat because its severity is not expected to change much over the next three generations of Chinook Salmon. Thus, any harvest impacts on current population levels would be negligible.

Threats calculator spreadsheets are included with this report (see Appendix 1).

Protection, status and ranks

Legal protection and status

In the United States of America, two Chinook Salmon Evolutionarily Significant Units (ESUs) are li

Non-legal status and ranks

IUCN red list – Chinook Salmon has not yet been assessed.

Acknowledgements and authorities contacted

Fisheries and Ocean Canada staff were contacted on multiple occasions. Special thanks to Gayle Brown, Gottfried Pestal, and Mary Thiess for their support through the data development and write up process. Laurelle Santana, Colleen Cranmer and Stella Chen, of ESSA Technologies Ltd. and Gwenn Farrell helped immensely in the formatting and structuring of the report.

Information sources

Alderdice, D.F., and F.P.J. Velsen. 1978. Relation between temperature and incubation time for eggs of Chinook Salmon (Oncorhynchus tshawytscha). Journal of the Fisheries Research Board of Canada 35:69-75.

Alexander, R.F., K.K. English, B.L. Nass, and S.A. Bickford. 1998. Distribution, timing and fate of radio-tagged adult Sockeye Salmon, Chinook Salmon, and Steelhead Salmon tracked at or above Wells Dam on the mid-Columbia River in 1997. Prepared for Public Utility District No. 1 of Douglas County, Washington.

Bailey, R., pers. comm. 2017. In-person at ESSA Technologies Ltd. November 1-2, 2017. Program Head, Chinook and Coho Operations Fraser and Interior Area Stock Assessment, Science Branch, Fisheries and Oceans Canada, 985 McGill Place, Kamloops, BC V2C 6X6.

Bakun, A. 1973. Coastal upwelling indices, west of North America, 1946-71. NOAA Tech. Rep. NMFS SSRF-671, 163 p. (Available from Natl. Mar. Fish. Serv., 2725 Montlake Blvd. E., Seattle, WA 98 1 12.)

Bakun, A. 1975. Daily and weekly upwelling indices, West Coast of North America, 1967-73. NOAA Tech. Rep. NMFS SSRF-693,114 p. (Available from Natl. Mar. Fish. Serv., 2725 Montlake Blvd. E., Seattle, WA 981 12.)

Barraclough, W.E., and A.C. Phillips. 1978. Distribution of juvenile salmon in the southern Strait of Georgia during the period April to July 1966-1969. Fish. Mar. Serv. Tech. Rep. 826:47p.

BC Hydro. 2011a. Bridge/Seton River Watershed: Salmonid Action Plan. 24 pp.

BC Hydro. 2011b. Puntledge River Watershed Salmonid Action Plan. 20 pp.

Beacham, T.D., and C.B. Murray. 1990. Temperature, egg size, and development of embryos and alevins of five species of Pacific salmon: a comparative analysis. Trans. Am. Fish. Soc. 119(6): 927-945.

Beacham, T.D., K.J. Supernault, M. Wetklo, B. Deagle, K. Labaree, J.R. Irvine, J.R. Candy, K.M. Miller, R.J. Nelson, and R.E. Withler. 2003. The geographic basis for population structure in Fraser River Chinook salmon (Oncorhynchus tshawytscha). Fishery Bulletin, 101(2), pp.229-243.

Beacham, T. D., and R.E. Withler. 2010. Comment on "Gene flow increases temporal stability of Chinook Salmon (Oncorhynchus tshawytscha) populations in the Upper Fraser River, British Columbia, Canada". Appears in Can. J. Fish. Aquat. Sci. 66: 167–176. Journal of the Fisheries Board of Canada, 67(1), 202–205.

Beamish, R.J. 1993. Climate and exceptional fish production off the west coast of North America. Canadian Journal of Fisheries and Aquatic Sciences 50: 2270–2291.

Beamish, R.J., and D.R. Bouillon. 1993. Pacific salmon production trends in relation to climate. Can. J. Fish. Aquat. Sci. 50:1002-1016.

Beamish, R.J., K.L. Lange, C.M. Neville, R.M. Sweeting, and T.D. Beacham. 2011. Structural patterns in the distribution of ocean- and stream-type juvenile Chinook Salmon populations in the Strait of Georgia in 2010 during the critical early marine period. NPAFC Doc. 1354. 27 pp.

Beamish, R.J., and C. Mahnken. 2001. A critical size and period hypothesis to explain natural regulation of salmon abundance and the linkage to climate and climate change. Progress in Oceanography 49: 423–437.

Beamish, R.J., and C.M. Neville. 2000. Predation-based mortality on juvenile salmon in the Strait of Georgia. N. Pac. Anadr. Fish Comm. Tech. Rep. 2: 11–12. Available at: http://www.npafc.org/new/publications/Bulletin/Bulletin percent20No. percent204/077-091Heard.pdf (presently not an active link). Accessed April 8, 2014.

Beamish, R.J., I.A. Pearsall, and M.C. Healey. 2003. A history of research on the early marine life of Pacific salmon off Canada's Pacific Coast. N. Pac. Anadr. Fish Comm. Bull 3:1-40.

Beamish, R. J., R.M. Sweeting, T.D. Beacham, K.L. Lange, and C.M. Neville. 2010. A late ocean entry life-history strategy improves the marine survival of Chinook Salmon in the Strait of Georgia. North Pacific Anadromous Fish Commission Doc. 1282. 14 pp. Fisheries and Oceans Canada, Pacific Biological Station.

Beamish, R.J., R.M. Sweeting, C.M. Neville, K.L. Lange, T.D. Beacham, and D. Preikshot. 2012. Wild Chinook Salmon survive better than hatchery salmon in a period of poor production. Env. Biol. Fish. 91:135-148.

Becker, C.D. 1973. Food and growth parameters of juvenile Chinook Salmon, Oncorhynchus tshawytscha, in central Columbia River. Fish. Bull, (U.S.) 71:387-400.

Becker, L.A., M.A. Pascual, and N.G. Basso. 2007. Colonization of the southern Patagonia Ocean by exotic Chinook salmon. Conservation Biology, 21(5), pp.1347-1352.

Bell, R. 1958. Time, size, and estimated numbers of seaward migrants of Chinook Salmon and Steelhead Trout in the Brownlee-Oxbow section of the middle Snake River. State of Idaho Department of Fish and Game, Boise, ID. 36 p.

Bentzen P., J.B. Olsen, J.E. McLean, T.R. Seamons, and T.P. Quinn. 2001. Kinship analysis of pacific salmon: insights into mating, homing, and timing of reproduction. The Journal of Heredity 92(2): 127-136.

Berejikian, B., and M. Ford. 2003. A review of relative fitness of hatchery and natural salmon (Preliminary Review Draft). National Marine Fisheries Service. 29 p.

Bjornn, T.C. 1971. Trout and salmon movements in two Idaho streams as related to temperature, food, stream flow, cover and population density. Trans. Am. Fish. Soc. 100:423-438.

Bond, N.A., M.F. Cronin, H. Freeland, and N. Mantua. 2015. Causes and impacts of the 2014 warm anomaly in the NE Pacific. Geophysical Research Letters, 42(9), pp.3414-3420.

Bradford, M.J., and J.R. Irvine. 2000. Land use, fishing, climate change, and the decline of Thompson River, British Columbia, Coho Salmon. Can. J. Fish. Aquat. Sci. 57:13-16.

Bradford, M.J., and Taylor, G.C. 1997. Individual variation in dispersal behaviour of newly emerged Chinook Salmon (Oncorhynchus tshawytscha) from the Upper Fraser River, British Columbia. Can. J. Fish. Aquat. Sci.54:1585 – 1592.

Brady, J.A. 1983. Lower Yukon River salmon test and commercial fisheries, 1981. Alaska Dep. Fish and Game ADFandG Tech. Data Rep. 89:91 p.

Brannon, E.L., and A. Setter. 1987. Marine distribution of a hatchery fall Chinook Salmon population. In E. Brannon and B. Jonsson (eds.), Proceedings of the Salmonid Migration and Distribution Symposium, p. 63-69. Trondheim, Norway.

Brannon, E.L., M.S. Powell, T.P Quinn, and A. Talbot. 2004. Population structure of Columbia River Basin Chinook Salmon and Steelhead Trout. Reviews in Fisheries Science, 12:99-232.

Braun, D.C., J.W. Moore, J. Candy, and R.E. Bailey. 2015. Population diversity in salmon: linkages among response, genetic and life-history diversity. Ecography, 39(3), 317–328.

Briggs, J.C. 1953. The behaviour and reproduction of salmonid fishes in a small coastal stream, Calif. Dep. Fish Game Fish. Bull. 94:62 p.

Brown, M.E. Thiess, and G. Pestal (in prep). Updated Status Information For Conservation Units of Southern BC Chinook Salmon. Canadian Technical Report of Fisheries and Aquatic Sciences.

Brown, G., S.J. Baillie, M.E. Thiess, J.R. Candy, C.K. Parken, G. Pestal, and D.M. Willis. 2013a. Pre-COSEWIC assessment of southern British Columbia Chinook Salmon (Oncorhynchus tshawytscha) populations. CSAP 2012/13 P23.

Brown, G.S., S.J. Baillie, R.E. Bailey, J.R. Candy, C.A. Holt, C.K. Parken, G.P. Pestal, M.E. Thiess, and D.M. Willis. 2013b. Pre-COSEWIC review of southern British Columbia Chinook Salmon (Oncorhynchus tshawytscha ) conservation units, Part II: Data, analysis and synthesis. DFO Can. Sci. Advis. Sec. Res. Doc. 2013/nnn. vi + xx p.

Brown, T. G., and P.M. Winchell. 2004. Fish Community of Shuswap Lake's Foreshore (Canadian Technical Report of Fisheries and Aquatic Sciences 2568) (pp. 1–60). Fisheries and Oceans Canada Science Branch, Pacific Region, Pacific Biological Station.

Brown, G., Thiess, M.E., Pestal, G., Holt, C.A, and Patten, B. In press. Integrated Biological Status Assessments under the Wild Salmon Policy Using Standardized Metrics and Expert Judgement: Southern British Columbia Chinook Salmon (Oncorhynchus tshawytscha) Conservation Units. DFO Can. Sci. Advis. Sec. Res. Doc. 2018/nnn. vi + xx p.

Buhle, E. R., K.K. Holsman, M.D Scheuerell, and A. Albaugh. 2009. Using an unplanned experiment to evaluate the effects of hatcheries and environmental variation on threatened populations of wild salmon. Biological Conservation, 142(11), 2449–2455.

Burner, C.J. 1951. Characteristics of spawning nests of Columbia River salmon. Fish. Bull. Fish Wildl. Serv. 61:97-110.

California HSRG (California Hatchery Scientific Review Group). 2012. California Hatchery Review Report. Prepared for the US Fish and Wildlife Service and Pacific States Marine Fisheries Commission. 100 p.

Candy, J. 2013. Quantifying genetic variation in southern BC Chinook Salmon. Presentation during Pre-COSEWIC workshop held on Feb 6, 2013.

Candy J.R., J.R. Irvine, C.K. Parken, S.L. Lemke, R.E. Bailey, M. Wetklo, and K. Jonsen. 2002. A discussion paper on possible new stock groupings (Conservation Units) for Fraser River Chinook Salmon. DFO Can. Sci. Advis. Sec. Res. Doc. 2002/085.

Carl, L.M. 1982. Natural reproduction of Coho Salmon and Chinook Salmon in some Michigan streams. N. Am. J. Fish. Manage. 2:375-380.

Cavalli-Sforza, L.L., and W.F. Edwards. 1967. Phylogenetic analysis models and estimation procedures. Am. J. Hum. Genet., 19, 233–257.

Chapman, D.W., and T.C. Bjornn. 1969. Distribution of salmonids in streams, with special reference to food and feeding, p. 153-176. In: T.G. Northcote (ed.). Symposium on Salmon and Trout in Streams. H.R. MacMillan Lectures in Fisheries. Institute of Fisheries, University of British Columbia, Vancouver, BC. 388 p.

Chilcote, M. W., K.W. Goodson, and M.R Falcy. 2011. Reduced recruitment performance in natural populations of anadromous salmonids associated with hatchery-reared fish. Journal of the Fisheries Board of Canada, 68(3), 511–522.

Clarke, C. N., D.J. Fraser, and C.F. Purchase. 2016. Lifelong and carry-over effects of early captive exposure in a recovery program for Atlantic salmon (Salmo salar). Animal Conservation, 19(4).

Chasco, B., I. C. Kaplan, A. Thomas, A. Acevedo-Gutiérrez, D. Noren, M.J. Ford, M. Bradley Hanson, J. Scordino, S. Jeffries, S. Pearson, K. N. Marshall, and E. J. Ward. 2017. Estimates of Chinook Salmon consumption in Washington State inland waters by four marine mammal predators from 1970 to 2015. Journal of the Fisheries Board of Canada, 74(8), 1173–1194.

Christie, M.R., M.L. Marine, R.A. French, and M.S. Blouin. 2012. Genetic adaptation to captivity can occur in a single generation. Proceedings of the National Academy of Sciences, 109(1), pp.238-242.

COSEWIC 2006. COSEWIC assessment and status report on the Chinook Salmon Oncorhynchus tshawytscha (Okanagan population) in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vii + 41 pp. (www.sararegistry.gc.ca/status/status_e.cfm, presently not an active link).

COSEWIC 2010. Appendix E7: COSEWIC Guidelines on Manipulated Populations.

COSEWIC ATK Subcommittee. 2014. ATK Assessment Report on Chinook Salmon (Oncorhynchus tshawytscha) in Canada for Vancouver Island, Sunshine Coast, and Fraser River [Revised]. Committee on the Status of Endangered Wildlife in Canada. Ottawa ON.

COSEWIC. 2015. COSEWIC Report on Proposed Designatable Units for Chinook Salmon Oncorhynchus tshawytcsha in Southern British Columbia.

Cullon, D. L., M.B. Yunker, C. Alleyne, N.J. Dangerfield, S. O'Neill, M.J. Whiticar, and P.S. Ross. 2009. Persistent organic pollutants in Chinook Salmon (Oncorhynchus tshawytscha): Implications for resident killer whales of British Columbia and adjacent waters. Environmental Toxicology and Chemistry, 28(1), 148–161.

d'Eon-Eggertson, N.K. Dulvy, and R.M. Peterman. 2014. Reliable identification of declining populations in an uncertain world. Conservation Letters doi: 10.1111/conl.12123.

Dahlberg, M., and D. Phinney. 1967. The use of adipose fin pigmentation for distinguishing between juvenile Chinook Salmon and Coho Salmon in Alaska. Journal of the Fisheries Research Board of Canada, 24(1), 209–210.

Dahlberg, M.L. 1982. Report of incidence of codedwire tagged salmonids in catches of foreign commercial and research vessels operating in the North Pacific Ocean and Bering Sea during 19801982. (Submitted to annual meeting International North Pacific Fisheries Commission, Tokyo, Japan, November 1982.) Auke Bay Laboratory, Northwest and Alaska Fisheries Center, National Marine Fisheries Service, Auke Bay, AK. 11p.

Dahlberg, M.L., and S. Fowler. 1985. Report of incidence of coded-wire-tagged salmonids in catches of foreign commercial and research vessels operating in the North Pacific Ocean and Bering Sea during 1984-85. (Submitted to annual meeting International North Pacific Fisheries Commission, Tokyo, Japan, November 1985.) Auke Bay Laboratory, Northwest and Alaska Fisheries Center, National Marine Fisheries Service, Auke Bay, AK. 16 p.

Dahlberg, M.L., P.P. Thrower, and S. Fowler. 1986. Incidence of coded-wire-tagged salmonids in catches of foreign commercial and research vessels operating in the North Pacific Ocean and Bering Sea in 1985-1986. (Submitted to annual meeting International North Pacific Fisheries Commission, Anchorage, Alaska, November 1986.) Auke Bay Laboratory, Northwest and Alaska Fisheries Center, National Marine Fisheries Service, Auke Bay, AK. 26 p.

de Mestral Bezanson, L., M.J. Bradford, S. Casley, K. Benner, T. Pankratz, and M. Porter. 2012. Evaluation of Fraser River Sockeye Salmon (Oncorhynchus nerka) spawning distribution following COSEWIC and IUCN Redlist guidelines. DFO Can. Sci. Advis. Sec. Res. Doc. 2012/064. v + 103 p.

Dery, S.J., M.A. Hernandez-Henriquez, P.N. Owens, M.W. Parkes, and E. L. Petticrew. 2012. A century of hydrological variability and trends in the Fraser River Basin. Environmental Research Letters. 7: 0204019 (10 pp).

DFO (Fisheries and Oceans Canada). 2005a. Canada's Policy for Conservation of wild Pacific Salmon. Fisheries and Oceans Canada, 401 Burrard Street, Vancouver, BC V6C 3S4. p. 49+v.

DFO (Fisheries and Oceans Canada). 2005b (draft). Evaluation of Hatchery Practices in the Salmonid Enhancement Program (SEP) based on System Wide Recommendations from the Hatchery Reform Project for Puget Sound and Coastal Washington. Fisheries and Oceans Canada; Oceans, Habitat and Enhancement Branch, Pacific Region.

DFO (Fisheries and Oceans Canada). 2005c (draft). Operational Guidelines for Pacific Salmon Hatcheries. Fisheries and Oceans Canada, Salmonid Enhancement Program. Pacific Region.

DFO (Fisheries and Oceans Canada). 2008. Aquatic Species at Risk – Chinook Salmon (Okanagan population). Available at: http://www.dfo-mpo.gc.ca/species-especes/species-especes/ChinookSalmon-saumonquinnat-eng.htm (presently not an active link). Accessed April 8, 2014.

DFO (Fisheries and Oceans Canada). 2012 (draft). SEP Production Planning: A Framework. Fisheries and Oceans Canada, Salmonid Enhancement Program. Pacific Region, Vancouver, BC.

DFO. (Fisheries and Oceans Canada) 2013a. Review and update of southern BC Chinook Salmon conservation unit assignments. DFO Can. Sci. Advis. Sec. Sci. Resp. 2013

DFO (Fisheries and Oceans Canada). 2013b (draft). Biological Risk Management Framework for Enhancing Salmon in the Pacific Region. Fisheries and Oceans Canada, Vancouver, BC.

DFO (Fisheries and Oceans Canada). 2016. State of the Physical, Biological and Selected Fishery Resources of Pacific Canadian Marine Ecosystems in 2015 (No. 3179). (P. C. Chandler, S. A. King, and R. I. Perry, Eds.) (pp. 1–240). Fisheries and Oceans Canada.

DFO (Fisheries and Oceans Canada). 2017. State of the Physical, Biological and Selected Fishery Resources of Pacific Canadian Marine Ecosystems in 2016 (No. 3225). (P. C. Chandler, S. A. King, and J. Boldt, Eds.) (pp. 1–251). Fisheries and Oceans Canada.

Diewart, R. 2007. Habitat requirements for ten Pacific salmon life-history strategies. Unpublished data. Prepared for Heather Stalberg, WSP Habitat Strategy Coordinator, Fisheries and Oceans Canada, Habitat and Enhancement Branch, Kamloops, BC.

Di Lorenzo, E., and N. Mantua. 2016. Multi-year persistence of the 2014/15 North Pacific marine heatwave. Nature Climate Change, 6(11), pp.1042-1047.

Dorner, B., M.J. Catalano, and R.M. Peterman. 2017. Spatial and temporal patterns of covariation in productivity of Chinook Salmon populations of the Northeastern Pacific. Canadian Journal of Fisheries and Aquatic Sciences, cjfas–2017–0197.

Ducommun, G. 2013. ATK Source Report on Chinook Salmon (Oncorhynchus tshawytscha) (Vancouver Island, Sunshine Coast, and Fraser River populations) in Canada. Prepared for Aboriginal Traditional Knowledge Sub-Committee of the Committee on the Status of Endangered Wildlife in Canada.

Dunford, W.E. 1975. Space and food utilization by salmonids in marsh habitats of the Fraser River estuary. M.Sc. thesis. University of British Columbia, Vancouver, BC. 81 p.

Dunmall, K.M., J.D. Reist, E.C. Carmack, J.A. Babaluk, M.P Heide-Jørgensen, and M.F. Docker. 2013. Pacific salmon in the Arctic: harbingers of change. Responses of Arctic Marine Ecosystems to Climate Change. Alaska Sea Grant, University of Alaska Fairbanks, pp.141-160.

Einum, S., A.P. Hendry and I.A. Fleming. 2002. Egg-size evolution in aquatic environments: does oxygen availability constrain size? Proceedings. Biological Sciences / the Royal Society, 269(1507), 2325–2330.

English, K.K., D. Peacock, and B. Spilsted. 2006. North and central coast core stock assessment program for salmon. Prepared by LGL Limited for the Pacific Salmon Foundation and Fisheries and Oceans Canada. 78 pp.

English, K. K., R.E. Bailey and D. Robichaud. 2007. Assessment of Chinook Salmon returns to the Fraser River watershed using run reconstruction techniques, 1982-04. Research Document 2007/020. Fisheries and Oceans Canada-Canadian Science Advisory Secretariat. pp. 1–84.

Everest, F.H. and D.W. Chapman. 1972. Habitat selection and spatial interaction by juvenile Chinook Salmon and Steelhead trout in two Idaho streams. J. Fish. Res. Board Can. 29:91-100.

Fabry V. J., B. A. Seibel, R. A. Feely, and J. C. Orr. 2008. Impacts of ocean acidification on marine fauna and ecosystem processes. ICES Journal of Marine Science 65: 414–432.

Farley, E.V., J.H. Moss, and R.J. Beamish. 2007. A review of the critical size, critical period hypothesis for juvenile Pacific salmon. North Pacific Anadromous Fish Commission Bulletin 4: 311–317.

Fedorenko, A.Y. and B.G. Shepherd. 1986. Review of Salmon Transplant Procedures and Suggested Transplant Guidelines. Salmonid Enhancement Program, Department of Fisheries and Oceans, Vancouver British Columbia. Can. Tech. Rep. Fish. Aquat. Sci. No. 1479. 144 p.

Felsenstein, J. 2004. PHYLIP (Phylogeny Inference Package) version 3.6. Distributed by the author. Department of Genome Sciences, University of Washington, Seattle.

Ferrari, M.R., J.R. Miller, and G.L. Russell. 2007. Modelling changes in summer temperature of the Fraser River during the next century. Journal of Hydrology 342: 336-346.

Ford, J.K.B. and G.M. Ellis. 2005. Prey selection and food sharing by fish-eating ‘resident' killer whales (Orcinus orca) in British Columbia. Can. Sci. Advisory Secretariat. Res. Doc. 2005/041. Fisheries and Oceans Canada, Pacific Biological Station, Nanaimo, B.C.

Ford, J.K.B. and G.M. Ellis. 2006. Selective foraging by fish-eating killer whales Orcinus orca in British Columbia. Marine Ecology Progress Series 316:185-199.

Ford, J.K.B. and Olesiuk, P.F. 2010. Hypothesis: Predation by marine mammals is an important contributor to the Fraser Sockeye Salmon situation. Summary of presentation at the Workshop on the Decline of Fraser River Sockeye Salmon, 15-17 June 2010, Nanaimo, B.C.

Ford, M., A. Murdoch, and S. Howard, S. 2012. Early male maturity explains a negative correlation in reproductive success between hatchery-spawned salmon and their naturally spawning progeny. Conservation Letters, 5(6), 450–458.

Ford, M.J., J. Hempelmann, M.B. Hanson, K.L. Ayres, R.W. Baird, C.K. Emmons, J.I. Lundin, G.S. Schorr, S.K. Wasser, and L.K. Park. 2016. Estimation of a killer whale (Orcinus orca) population's diet using sequencing analysis of DNA from feces. Plos one, 11(1), p.e0144956.

Fraser D.J., Starr, P.J. and A.Y. Federenko. 1982. A review of Chinook Salmon and Coho Salmon of the Fraser River. Canadian Technical Report of Fisheries and Aquatic Sciences 1125.

Gardner, J., D.L. Peterson, A. Wood, and V. Maloney. 2004. Making Sense of the Debate about Hatchery Impacts: Interactions Between Enhanced and Wild Salmon on Canada's Pacific Coast. Pacific Fisheries Resource Conservation Council. 187 pp.

Goodman, D. 1975. A synthesis of the impacts of proposed expansion of the Vancouver International Airport and other developments on the fisheries resources of the Fraser River estuary. Vol. I and II, Section II. In: Fisheries resources and food web components of the Fraser River estuary and an assessment of the impacts of proposed expansion of the Vancouver International Airport and other developments on these resources. Prepared by Department of Environment, Fisheries and Marine Service. Environment Canada, Vancouver, BC.

Goudet, J., Raymond, M., de Meeus, T. and Rousset, F., 1996. Testing differentiation in diploid populations. Genetics 144: 1931-1938.

Groot, C. and L. Margolis eds., 1991. Pacific salmon life histories. UBC press.

Guimond, E. 2008. Puntledge River impoundment and diversion dam fishway assessment 2007. Prepared for Comox Valley Project Watershed Society. 21 pp.

Gustafson R.G., W.H. Lenarz, B.B. McCain, C.C. Schmitt, W.S. Grant, T.L. Builder, and R.D. Methot. 2000. Status review of Pacific Hake, Pacific Cod, and Walleye Pollock from Puget Sound,Washington. U.S. Dept. Commer., NOAA Tech. Memo. NMFS-NWFSC- 44, 275 p.

Hallock, R.J., D.H. Fry, Jr., and D.A. LaFaunce. 1957. The use of wire fyke traps to estimate the runs of adult salmon and Steelhead Salmon in the Sacramento River. Calif. Fish Game 43:271-298.

Hankin, D.G., J.H. Clark, R.B. Deriso, J.C. Garza, G.S. Morishima, B.E. Riddell, C. Schwarz, and J.B. Scott. 2005. Report of the Expert Panel on the Future of the Coded Wire Tag Program for Pacific Salmon. PSC Tech. Rep. No. 18, November 2005. 300 p (includes agency responses as appendices).

Hanson, M. B., R.W. Baird, J.K.B. Ford, J. Hempelmann-Halos, D.M. Van Doornik, J.R. Candy, C.K. Emmons, G.S. Schorr, B. Gisborne, K.L. Ayres, S. K. Wasser, K.C. Balcomb, K. Balcomb-Bartok, J.G. Sneva, and M.J. Ford 2010. Species and stock identification of prey consumed by endangered southern killer whales in their summer range. Endangered Species Research 11: 69-82.

Hart, J.L. 1973. Pacific fishes of Canada. Bull. Fish. Res. Board Can. 180:740 p.

Harvell, C.D., C.E. Mitchell, J.R. Ward, S. Altizer, A.P. Dobson, R.S. Ostfeld, and M.D. Samuel. 2002. Climate warming and disease risk for terrestrial and marine biota. Science 296: 2158-2162 plus Supplemental material.

Healey, M.C. 1980a. The ecology of juvenile salmon in Georgia Strait, British Columbia, p. 203-229. In: W.J. McNeil and D.C. Himsworth (eds.). Salmonid ecosystems of the North Pacific. Oregon State University Press, Corvallis, OR.

Healey, M.C. 1980b. Utilization of the Nanaimo River estuary by juvenile Chinook Salmon, Oncorhynchus tshawytscha. Fish. Bull, (u.s.) 77:653-668.

Healey, M.C. 1982. Catch, escapement, and stock-recruitment for British Columbia Chinook Salmon since 1951. Canadian Technical Report of Fisheries and Aquatic Sciences 1107.

Healey, M.C. 1983. Coastwide distribution and ocean migration patterns of stream- and ocean-type Chinook Salmon, Oncorhynchus tshawytscha. Canadian Field-Naturalist 97(4): 427-433.

Healey, M.C. 1991. Life history of Chinook Salmon (Oncorhynchus tshawytscha). Pages 311-394 in C. Groot and L. Margolis, editors. Pacific Salmon Life Histories. University of British Columbia Press, Vancouver, B.C.

Healey. M.C. 2001. Patterns of gametic investment by female stream- and ocean-type Chinook Salmon. Journal of Fish Biology 58: 1545-1556.

Healey, M.C. and C. Groot. 1987. Marine migration and orientation of ocean-type Chinook Salmon and Sockeye Salmon. Am. Fish. Soc. Symp. 1:2998-312.

Healey, M.C. and F.P. Jordan. 1982. Observations on juvenile Chum Salmon and Chinook Salmon and spawning Chinook Salmon in the Nanaimo River, British Columbia, during 1975-1981. Canadian Manuscript Report of Fisheries and Aquatic Science. 1659: 1-31.

Healey, M.C, and W.R. Heard. 1984. Inter- and intra-population variation in the fecundity of Chinook Salmon (Oncorhynchus tshawytscha) and its relevance to life-history theory. Can. J. Fish. Aquat. Sci. 41:476-483.

Heard, W.R., E. Shevlyakov, O.V. Zikunova, and R.E. McNicol. 2007. Chinook Salmon – trends in abundance and biological characteristics. North Pacific Anadromous Fish Commission. Bulletin No. 4: 77-91.

Hertz, E., M. Trudel, R. El-Sabaawi, S. Tucker, J.F. Dower, T.D. Beacham, A. Edwards, and A. Mazumder. 2016a. Hitting the moving target: modelling gradual ontogenetic niche shifts using stable isotopes. J. Anim. Ecol. 85: 681-691.

Hertz, E., M. Trudel, R. El-Sabaawi, S. Tucker, J.F. Dower, T.D. Beacham, C. Parken, D. Mackas, and A. Mazumder. 2016b. Influences of ocean conditions and feeding ecology on the survival of juvenile Chinook Salmon (Oncorhynchus tshawytscha). Fish. Oceanogr. 25: 407-419.

Hillman, T.W., J.S. Griffith, and W.S. Platts. 1987. Summer and winter habitat selection by juvenile Chinook Salmon in a highly sedimented Idaho stream. Trans. Am. Fish. SOC. 116: 185-195.

Hoekstra, J. M., K. K. Bartz, M. H. Ruckelshaus, J. M. Moslemi, and T. K. Harms. 2007. Quantitative threat analysis for management of an imperiled species-Chinook Salmon (Oncorhynchus tshawytscha). Ecological Applications, 17:2061-2073.

Holsman, K.K., M.D. Scheuerell, E.R. Buhle, and R. Emmett. 2012. Interacting effects of translocation, artificial propagation, and environmental conditions on the marine survival of Chinook Salmon from the Columbia River, Washington, U.S.A. Conservation Biology 26: 912–922.

Holt, C.A. and Ogden, A., 2013. Software for Assessing Status of Conservation Units under Canada's Wild Salmon Policy: Instruction Manual, Nanaimo, Canada.

Holtby, L.B. and K.A. Ciruna. 2007. “Conservation Units for Pacific Salmon Under the Wild Salmon Policy”. Vol. 3848.

HSRG (Hatchery Scientific Review Group). April 2004. Hatchery Reform: Principles and Recommendations of the HSRG. 1305 Fourth Avenue, Suite 810, Seattle, WA 98101. Available from www.hatcheryreform.org (presently not an active link).

Irvine, J.R. 1986. Effects of varying discharge on the downstream movement of salmon fry, (Oncorhynchus tshawytscha) Walbaum. J. Fish Biol. 28:17-28

Irvine, J. R., E. Linn, K. Gillespie, J.D. Reist and C. McLeod. 2009. Pacific Salmon in Canada's Arctic Draining rivers, With Emphasis on Those in British Columbia and the Yukon (pp. 1–32). Pacific Fisheries Resource Conservation Council.

Irvine, J.R. and Crawford, W.R. 2012. State of the physical biological, and selected fishery resources of Pacific Canadian marine ecosystems in 2011. DFO Can. Sci. Advis. Sec.Res. Doc. 2012/072.

IUCN 2009. Salmon and Climate Change: Fish in Hot Water. International Union for the Conservation of Nature Salmon (IUCN) SSC Salmonid Specialist Group, 4 p.

IUCN 2014. IUCN Red List of Threatened Species. Version 2014.1. Downloaded on 02 July 2014.

Johnson, J., T. Johnson and T. Copeland. 2012. Defining life histories of precocious male parr, minijack, and jack Chinook Salmon using scale patterns. Transactions of the American Fisheries Society, (141), 1545–1556.

Kapoor, B.G. and B. Khanna. 2004. Ichthyology Handbook. Pages 137–140, Springer. ISBN 978-3-540-42854-1.

Keefer, M.L., C.C. Caudill, C.A. Peery, and C.T. Boggs. 2008. Non-direct homing behaviours by adult Chinook Salmon in a large, multi-stock river system. Journal of Fish Biology 72: 27-44.

Kjelson, M.A., P.P. Raquel, and F.W. Fisher. 1981. Influences of freshwater inflow on Chinook Salmon (Oncorhynchus tshawytscha) in the Sacramento-San Joaquin estuary, p. 88-102. In: R.D. Cross and D.L. Williams (eds.). Proceedings of the National Symposium on Freshwater Inflow to Estuaries, U.S. Fish Wildl. Serv. Biol. Serv. Prog. Fws/OBS-81/04(2).

Kilduff, D.P., E. Di Lorenzo, L.W. Botsford, and S.L. Teo. 2015. Changing central Pacific El Niños reduce stability of North American salmon survival rates. Proceedings of the National Academy of Sciences, 112(35), pp.10962-10966.

Kjelson, M.A., P.P. Raquel, and F.W. Fisher. 1982. Life history of fall-run juvenile Chinook Salmon, Oncorhynchus tshawytscha, in the Sacramento-San Joaquin estuary, California, p. 393-411. In: V.S. Kennedy (ed.). Estuarine comparisons. Academic Press, New York, NY.

Komori, V. 1997. Strategic fisheries overview for the Bridge/Seton Habitat Management Area. Prepared for the Fraser River Action Plan, Fisheries and Oceans Canada. 88 pp. + appendices.

Lehnert, S.J., T.E. Pitcher, R.H. Devlin and D.D. Heath. 2016. Red and white Chinook Salmon: genetic divergence and mate choice. Molecular Ecology, 25(6), 1259–1274.

Leitritz, E. and R.C. Lewis. 1976. Trout and salmon culture. California Department of Fish and Game, Fish Bull, Sacramento, CA.

Levings, C.D. 1982. Short term use of a low tide refuge in a sandflat by juvenile Chinook Salmon, Oncorhynchus tshawytscha, Fraser River estuary. Can. Tech. Rep. Fish. Aquat. Sci. 1111:33 p.

Levy, D.A. and T.G. Northcote. 1981. The distribution and abundance of juvenile salmon in marsh habitats of the Fraser River estuary. Westwater Res. Cent. Univ. Br. Col. Tech. Rep. 25:117 p.

Levy, D.A. and T.G. Northcote. 1982. Juvenile salmon residency in a marsh area of the Fraser River estuary. Can. J. Fish. Aquat. Sci. 39:270-276.

Levy, D.A., T.G. Northcote, and G.J. Birch. 1979. Juvenile salmon utilization of tidal channels in the Fraser River estuary, British Columbia. Westwater Res. Cent. Univ. Br. Col. Tech. Rep. 23: 70p.

Lister, D.B. and C.E. Walker. 1966. The effect of flow control on freshwater survival of Chum Salmon, Coho Salmon, and Chinook Salmon in the Big Qualicum River. Can. Fish Cult. 37:3-25.

Lister, D.B., C.E. Walker, and M.A. Giles. 1971. Cowichan River Chinook Salmon escapements and juvenile production 1965-1967. Fish. Serv. (Can.) Pac. Reg. Tech. Rep. 1971-3: 8 p.

MacKinlay, D.D., S. Lehmann, J. Bateman, and R. Cook. 2004. Pacific salmon hatcheries in British Columbia. Pages 57–75 in M. J. Nickum, P. M. Mazik, J. G. Nickum, and D. D. MacKinlay, editors. Propagated fish in resource management. American Fisheries Society, Symposium 44, Bethesda, Maryland.

Magnusson, A. 2001. Survival rates of Coho Salmon and Chinook Salmon released from hatcheries on the US and Canadian coast 1972-1998, with respect to climate and habitat effects. M.Sc. Thesis, University Washington Scholl Fisheries Aquatic Sciences. 115 p.

Mains, E.M. and J.M. Smith. 1964. The distribution, size, time, and current preferences of seaward migrant Chinook Salmon in the Columbia and Snake rivers. Wash. Dep. Fish. Fish. Res. Pap. 2:5-43.

Major, R.L. and J.L. Mighell. 1969. Egg-to-migrant survival of spring Chinook Salmon (Oncorhynchus tshawytscha) in the Yakima River, Washington. Fish. Bull. (u.s.) 67:347-359.

Major, R.L., J. Ito, S. Ito, and H. Godfrey. 1978. Distribution and origin of Chinook Salmon (Oncorhynchus tshawytscha) in offshore waters of the North Pacific Ocean. Int. North Pac. Fish. Comm. Bull. 38:54 p.

Malick, M.J., S.P. Cox, F.J. Mueter, B. Dorner, and R.M. Peterman. 2017. Effects of the North Pacific Current on the productivity of 163 Pacific salmon stocks. Fisheries Oceanography, 26(3), pp.268-281.

Manchester-Neesvig, J.B., K. Valters, and W.C. Sonzogni. 2001. Comparison of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in Lake Michigan salmonids. Environmental science and technology, 35(6), pp.1072-1077.

Mantua, N.J., S.R. Hare, Y. Zhang, J.M. Wallace, and R.C. Francis. 1997. A Pacific interdecadal climate oscillation with impacts on salmon production. Bulletin of the American Meteorological Society 78: 1069–1079.

Master, L. L., D. Faber-Langendoen, R. Bittman, G. A. Hammerson, B. Heidel, L. Ramsay, K. Snow, A. Teucher, and A. Tomaino. 2012. NatureServe Conservation Status Assessments: Factors for Evaluating Species and Ecosystem Risk. NatureServe, Arlington, VA.

McCullough, D.A. 1999. A review and synthesis of effects of alterations to the water temperature regime on freshwater life stages of salmonids with special reference to Chinook Salmon. U.S. EPA, Region 10, Seattle, WA.

McDowall, R.M. 1994. The origins of New Zealand's Chinook Salmon, Oncorhynchus tshawytscha. Mar. Fish. Rev. 56: 1–7.

McGregor, E.A. 1922. Observations on the egg yield of Klamath River king salmon. Calif. Fish Game 8:160-164.

McGregor, E.A. 1923. A possible separation of the river races of king salmon in ocean-caught fish by means of anatomical characters. Calif. Fish Game 9:138-150.

McLeod, C.L. and J.P. O'Neil. 1983. Major range extensions of anadromous salmonids and first record of Chinook Salmon in the Mackenzie River drainage. Can. J. Zool. 61:2183-2184.

McPhail, J.D. 2007. The Freshwater Fishes of British Columbia. University of Alberta Press, lxxiv + 620 pp.

McPhail, J.D., and C.C. Lindsey. 1970. Freshwater fishes of northwestern Canada and Alaska. Bull. Fish. Res. Board. Can. 173:381p.

McPhail, J.D., and R. Carveth. 1994. Field key to the Freshwater Fishes of British Columbia. Province of British Columbia, Resources Inventory Committee.

McPhail, J.D. and Lindsey, C.C. 1986. Zoogeography of the freshwater fishes of Cascadia (the Columbia system and rivers north to the Stikine). Pages 615-637 In Hocutt, C.H. and E.O. Wiley eds. The zoogeography of North American freshwater fishes. John Wiley and Sons, New York.

Meehan, W.R. and D.B. Siniff. 1962. A study of the downstream migrations of anadromous fishes in the Taku River, Alaska. Trans. Am. Fish. Soc. 91:399-407.

Middleton, K.A. 2011. Factors affecting overwinter mortality and early marine growth in the first ocean year of juvenile Chinook Salmon in Quatsino Sound, British Columbia.

Miller K.M., A.D. Schulze, N. Ginther, S. Li, P.A. Patterson, A.P. Farrell, and S.G. Hinch. 2009. Salmon spawning migration: metabolic shifts and environmental triggers. Comparative Biochemistry and Physiology, D: 75–89.

Mooney, H., A. Larigauderie, M. Cesario, T. Elmquist, O. Hoegh-Guldberg, S. Lavorel, G. M. Mace, M. Palmer, R. Scholes, and T. Yahara 2009. Biodiversity, climate change, and ecosystem services. Current Opinion in Environmental Sustainability 1: 46-54.

Moore, S.K., V.L. Trainer, N.J. Mantua, M. S. Parker, E.A. Laws, L.C. Backer, and L.E. Fleming. 2008. Impacts of climate variability and future climate change on harmful algal blooms and human health. Environmental Health 7 (Suppl 2): S4 (12 pg.).

Moran, P., D.J. Teel, M.A. Banks, T.D. Beacham, M.R. Bellinger, S.M. Blankenship et al. 2013. Divergent life-history races do not represent Chinook Salmon coast-wide: the importance of scale in Quaternary biogeography. Journal of the Fisheries Board of Canada, 70(3), 415–435.

Morrison, J., M.C. Quick, and M.G.G. Foreman. 2002 Climate change in the Fraser River watershed: flow and temperature projections. Journal or Hydrology 263: 230-244.

Morley, R.B., A.Y. Fedorenko, H.T. Bilton, and S.J. Lehmann. 1996. The effects of time and size at release on returns at maturity of Chinook Salmon from Quinsam River Hatchery, B.C., 1982 and 1983 releases. Can. Tech. Rep. Fish. Aquat. Sci. 2105:88 p.

Moritz, C. 2002. Strategies to protect biological diversity and the evolutionary processes that sustain it. Systematic Biology 51(2): 238 – 254.

Morrison, J., M.C. Quick, and M.G.G. Foreman. 2002 Climate change in the Fraser River watershed: flow and temperature projections. Journal or Hydrology 263: 230-244.

Mueter, F.J., B.J. Pyper, and R.M. Peterman. 2002. Opposite effects of ocean temperature on survival rates of 120 stocks of Pacific salmon (Oncorhynchus spp.) in northern and southern areas. Canadian Journal of Fisheries and Aquatic Sciences 59: 456–463.

Mueter, F. J., B. J. Pyper, and R. M. Peterman. 2005. Relationships between coastal ocean conditions and survival rates of northeast Pacific salmon at multiple lags. Transactions of the American Fisheries Society 134: 105-119.

Mundie, J.H. 1969. Ecological implications of the diet of juvenile Coho Salmon in streams, p. 135-152. In: T.G. Northcote (ed.). Symposium on Salmon and Trout in streams. H.R. MacMillan Lectures in— Fisheries. Institute of Fisheries, University of British Columbia, Vancouver, BC.

Murphy, M.L., J. Heifetz, J.F. Thedinga, S.W. Johnson, and K.V. Koski. 1989. Habitat utilization by juvenile Pacific salmon (Oncorhynchus) in the glacial Taku River, southeast Alaska. Can. J. Fish. Aquat. Sci. 46:1677-1685.

Myers, K.W., C.K. Harris, C.M. Knudsen, R.V. Walker, N.D. Davis, and D.E. Rogers. 1987. Stock origins of Chinook Salmon in the area of the Japanese mothership salmon fishery. N. Am. J. Fish. Manag. 7:459-474.

Myers, J.M., R.G. Kope, G.J. Bryant, D. Teel, L.J. Lierheimer, T.C. Wainwright, W.S. Grand, F.W. Waknitz, K. Neely, S.T. Lindley, and R.S. Waples. 1998. Status Review of Chinook Salmon from Washington, Idaho, Oregon and California. U.S. Dept. Commerce, NOAA. Tech. Memo. NMFS-NWFSC-35, 443 p.

Myers, K.W., R.V. Walker, N.D. Davis, J.A. Armstrong, W.J. Fournier, N.J. Mantua, and J. Raymond-Yakoubian. 2010. Climate-ocean effects on Chinook Salmon. Arctic-Yukon Kuskokwim Sustainable Salmon Initiative, Project Final Product. SAFS-UW-1003. School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA. Accessed April 8, 2014.

Nandor, G.F., J.R. Longwill, and D.L. Webb. 2010. Overview of the coded-wire tag program in the Greater Pacific Region of North America, in Wolf, K.S. and O'Neal, J.S., eds., PNAMP Special Publication: Tagging, Telemetry and Marking Measures for Monitoring Fish Populations—A compendium of new and recent science for use in informing technique and decision modalities: Pacific Northwest Aquatic Monitoring Partnership Special Publication 2010-002, chap. 2, p. 5 - 46.

National Wildlife Federation. 2002. Chinook Salmon. Available at: http://www.nwf.org/Wildlife/Wildlife-Library/Amphibians-Reptiles-and-Fish/Chinook-Salmon.aspx (presently not an active link). Accessed April 11, 2014.

Neave, F. 1943. Diurnal fluctuations in the upstream migration of Coho Salmon and spring salmon. J. Fish. Res. Board Can. 6:158-163.

Neilson, J.D. and C.E. Banford. 1983. Chinook Salmon (Oncorhynchus tshawytscha) spawner characteristics in relation to redd physical features. Can. J. Zool. 61:1524-1531.

Neilson, J.D. and G.H. Geen. 1981. Enumeration of spawning salmon from spawner residence time and aerial counts. Trans. Am. Fish. Soc. 110:554-556.

Netboy, A. 1958. Salmon of the Pacific Northwest. Fish vs. Dams. Binfords and Mort, Portland, OR, 119 p.

Nickelson, T. E. 1986. Influences of upwelling, ocean temperature, and smolt abundance on marine survival of Coho Salmon (Oncorhynchus kisutch) in the Oregon Production Area. Canadian Journal of Fisheries and Aquatic Sciences 43: 527-535.

Nickelson, T. 2003. The influence of hatchery Coho Salmon (Oncorhynchus kisutch) on the productivity of wild Coho Salmon populations in Oregon coastal basins. Journal of the Fisheries Board of Canada, 60(9), 1050–1056.

NOAA (National Oceanic and Atmospheric Administration) Fisheries. 2014a. Pacific Salmonids: Major Threats and Impacts. Available at: http://www.nmfs.noaa.gov/pr/species/fish/salmon.htm (presently not an active link). Accessed April 8, 2014.

NOAA (National Oceanic and Atmospheric Administration) Fisheries. 2014b. Chinook Salmon (Onchorhynchus tshawytscha). Available at: http://www.nmfs.noaa.gov/pr/species/fish/chinooksalmon.htm (presently not an active link). Accessed April 8, 2014.

NOAA (National Oceanic and Atmospheric Administration). NOAA National Centers for Environmental Information, State of the Climate: Global Climate Report for November 2017, published online December 2017, retrieved on December 22, 2017.

Northcote, T.G., N.T. Johnston, and K. Tsumura. 1979. Feeding relationships and food web structure of lower Fraser River fishes. Westwater Res. Cent. Univ. Br. Col. Tech. Rep. 16:73 p.

Noyes, P.D., M.K. McElwee, H.D. Miller, B.W. Clark, L.A. Van Tiem, K.C. Walcott, K.N. Erwin, and E.D. Levin. 2009. The toxicology of climate change: environmental contaminants in a warming world. Environment International 35: 971-986.

Olesiuk, P.F. 1993. Annual prey consumption by harbor seals (Phoca vitulina) in the Strait of Georgia, British Columbia. Fish. Bull. 91:491-515.

Olesiuk, P.F. 2010. An assessment of population trends and abundance of Harbour Seals (Phoca vitulina) in British Columbia. DFO Can. Sci. Advis. Sec. Res. Doc. 2009/105. vi + 157 p.

Olesiuk, P.F., G. Horonowitsch, G.M. Ellis, T.G. Smith, L. Flostrand, and S. Warby. 1996. Predation by Harbour Seals (Phoca vitulina) on outmigrating salmon (Oncorhynchus spp.) fry and smolts in the lower Puntledge River, British Columbia. PSARC working paper S96-12. 112p.

Olesiuk, P. F., G. M. Ellis and J.K. Ford. 2006. Life History and Population Dynamics of Northern Resident Killer Whales (Ornicus orca) in British Columbia. Research Document 2005/045. pp. 1–81. DFO - Canadian Science Advisory Secretariat.

Olesiuk, P.F., S.J. Jeffries, M.M. Lance, A.W. Trites, P.J. Gearing, K. Miller-Saunders, A. Tabata, S.D. Riemer, and D.M. Lambourn. 2010. Prey requirements and salmon consumption by Steller Sea Lions (Eumetopias jubatus) in southern British Columbia and Washington State. Unpubl. Draft working paper reviewed at National Marine Mammal Peer Review Committee meeting, November 2010, Mont Joli, QC.

Orr, J. C., V.J. Fabry, O. Aumont et al. 2005. Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. Nature 437, 681-686.

Parken, C.K., J.R. Candy, J.R. Irvine, and T.D. Beacham, T.D. 2008. Genetic and coded-wire results combine to allow more-precise management of a complex Chinook Salmon aggregate. North American Journal of Fisheries Management 28:328-340.

Pearcy, W.G. 1992. Ocean Ecology of North Pacific Salmonids. University of Washington Press, Seattle, WA.

Pearcy, W. G. and S. M. McKinnell. 2007. The ocean ecology of salmon in the northeast Pacific Ocean – man abridged history. American Fisheries Society Symposium 57: 7-30.

Perry, R. W., J. M. Plumb, and C. W. Huntington. 2015. Using a laboratory-based growth model to estimate mass- and temperature-dependent growth parameters across populations of juvenile Chinook salmon. Transactions American Fisheries Society 144:331–336.

Peterman, R.M. 1987. Review of the components of recruitment of Pacific salmon. In: M. Dadswell, R. Klauda, C. Moffitt, R. Saunders, R. Rulifson, and J.E. Cooper (eds.), Common Strategies of Anadromous and Catadromous Fishes, American Fisheries Society Symposium 1: 417-429.

Pike, R.G., K.E. Bennett, T.E. Redding, A.T. Werner, D.L. Spittlehouse, R.D. Moore, T.Q. Murdock, J. Beckers, B.D. Smerdon, D.D. Bladon, V.N. Foord, D.A. Campbell and P.J. Tschaplinski. 2010. In Compendium of forest hydrology and geomorphology in British Columbia. Pike, R.G., T.E. Redding, R.D. Moore, R.D. Winker and K.D. Bladon (editors). Compendium of forest hydrology and geomorphology in British Columbia. B.C. Min. For. Range, For. Sci. Prog., Victoria, B.C. and FORREX Forum for Research and Extension in Natural Resources, Kamloops, B.C. Land Manag. Handb. 66.

Plumb, J. M., and C. M. Moffitt. 2015. Re-estimating temperature-dependent consumption parameters in bioenergetics models for juvenile Chinook salmon. Transactions of the American Fisheries Society 144:323–330.

Plummer, Martyn. 2011. Jags. Sourceforge.

Porszt, E.J., R.M. Peterman, N.K. Dulvy, A.B. Cooper, and J.R. Irvine. 2012. Reliability of indicators of decline in abundance. Conservation Biology 26: 894-904.

Porter, M., and M. Nelitz. 2009. A future outlook on the effects of climate change on Chinook Salmon (Oncorhynchus tshawytscha) habitats in the Cariboo-Chilcotin. Prepared by ESSA Technologies Ltd. for Fraser Salmon and Watersheds Program, B.C. Ministry ofmEnvironment, and Pacific Fisheries Resource Conservation Council.

Porter, M., S. Casley, D. Pickard, M. Nelitz, and N. Ochoski. 2013. Southern Chinook Salmon Conservation Units: Habitat Indicators Report Cards. Report prepared by ESSA Technologies Ltd. for Fisheries and Oceans Canada.

Prakash, A. 1962. Seasonal changes in feeding of Coho Salmon and Chinook Salmon (spring) salmon in southern British Columbia waters. J. Fish. Res. Board Can. 19:851-866.

Preikshot, D., R.J. Beamish, and C.M. Neville. 2013. A dynamic model describing ecosystem-level changes in the Strait of Georgia from 1960 to 2010. Progress in Oceanography, 115, pp.28-40.

Pritchard, A.L. and A.L. Tester. 1944. Food of spring and Coho Salmon in British Columbia. Bull. Fish. Res. Board Can. 65:23p.

PSC-CTC (Pacific Salmon Commission Joint Chinook Salmon Technical Committee). 1987. Data report of the CTC on unaccounted for sources of fishing associated mortalities of Chinook Salmon in west coast salmon fisheries. TCCHINOOK (87)-3. 14 pg. Vancouver, B.C.

PSC-CTC (Pacific Salmon Commission Joint Chinook Salmon Technical Committee). 2012a. 2012 Exploitation Rate Analysis and Model Calibration. Pacific Salmon Commission Report TCCHINOOK (12)-04. Vancouver, B.C.

PSC-CTC (Pacific Salmon Commission Joint Chinook Salmon Technical Committee). 2012b. 2012 annual report of the exploitation rate analysis and model calibration. Pacific Salmon Commission Report TCCHINOOK (12)-4, Vancouver, B.C.

PSC-CTC (Pacific Salmon Commission Joint Chinook Salmon Technical Committee). 2016. Special Report Investigation of Maturation-Rate Estimation Models and their Influence on PSC Chinook Salmon Model Abundance Indices. Pacific Salmon Commission Report No. TCCHINOOK (16)-1) (pp. 1–90). Vancouver, BC.

PSC-CTC (Pacific Salmon Commission Joint Chinook Salmon Technical Committee). 2017a. 2016 Exploitation Rate Analysis and Model Calibration Supplement Data Notebook.Pacific Salmon Commission Report TCCHINOOK (17)-01). 1–97, Vancouver, B.C.

PSC-CTC (Pacific Salmon Commission Joint Chinook Salmon Technical Committee). 2017b. Annual Report of Catch and Escapement for 2016. Pacific Salmon Commission Report TCCHINOOK (17)-2 (pp. 1–225), Vancouver, B.C.

Puget Sound Partnership Climate and Chinook Salmon Guidance (Version 1.0 September 2017), 32 p.

Pyper, B.J., F.J. Mueter, and R.M. Peterman. 2005. Across-species comparisons of spatial scales of environmental effects on survival rates of Northeast Pacific salmon. Transactions of the American Fisheries Society 134(1): 86-104.

Quinn, T.P. 2005. The behavior and ecology of Pacific salmon and trout. Univ. Wash. Press. 278p.

Quinn, T.P., and S. Bloomberg. 1992. Fecundity of Chinook Salmon (Oncorhynchus tshawytscha) from the Waitaki and Rakaia rivers, New Zealand. New Z. J. Mar. and Freshwater Res. 26:429-434.

R Core Team. 2017. R: A language and environment for statistical computing. Vienna, Austria: R Foundation for Statistical Computing.

Raymond, M. and F. Rousset. 1995. GENEPOP (version 1.2): population genetics software for exact tests and ecumenicism. J. Heredity, 86:248-249.

Raymond, H.L. 1968. Migration rates of yearling Chinook Salmon in relation to flows and impoundments in the Columbia and Snake rivers. Trans. Am. Fish. Soc. 97:356-359.

Raymond, H.L. 1988. Effects of hydroelectric development and fisheries enhancement on spring and summer Chinook Salmon and Steelhead Salmon in the Columbia River basin. North American Journal of Fisheries Management. 8:1-24.

Real, L.A. 1980. Fitness, uncertainty, and the role of diversification in evolution and behavior. Amer. Nat. 155:623-638.

Reid, G. 1961. Stomach content analysis of trollcaught king and Coho Salmon, southeastern Alaska, 1957-1958. u.s. Fish Wildl. Serv. Spec. Sci. Rep. Fish. 379:8 p.

Reimers, P.E. 1968. Social behaviour among juvenile fall Chinook Salmon. J. Fish. Res. Board Can. 25:2005-2008.

Reimers, P.E. 1971. The length of residence of juvenile fall Chinook Salmon in Sixes River, Oregon. Ph.D. thesis. Oregon State University, Corvallis, OR. 99 p.

Rensel, J.E., N. Haigh, and T.J. Tynan. 2010. Fraser River Sockeye Salmon marine survival decline and harmful blooms of Heterosigma akashiwo. Harmful Algae 10: 98-115.

Rich, W.H. 1925. Growth and degree of maturity of Chinook Salmon in the ocean. Bull. Bur. Fish. (U.S.) 41:15-90.

Rich, W.H. 1942. The salmon runs of the Columbia River in 1938. Fish. Bull. Fish Wildl. Serv. 50:101-147.

Richter A. and S.A. Kolmes. 2005. Maximum temperature limits for Chinook Salmon, Coho Salmon, and Chum Salmon, and Steelhead Trout in the Pacific Northwest. Rev. Fish. Sci. 13:23-49.

Ricker, W.E. 1972. Hereditary and environmental factors affecting certain salmonid populations. In: R. C. Simon and P. A. Larkin (eds.), The Stock Concept in Pacific Salmon. MacMillan Lectures in Fisheries, p. 27-160. Univ. B.C., Vancouver, B.C.

Riddell, B., M. Bradford, R. Carmichael, D. Hankin, R. Peterman, and A. Wertheimer. 2013. Assessment of Status and Factors for Decline of Southern BC Chinook Salmon: Independent Panel's Report. Prepared with the assistance of D.R. Marmorek and A.W. Hall, ESSA Technologies Ltd., Vancouver, B.C. for Fisheries and Oceans Canada (Vancouver. BC) and Fraser River Aboriginal Fisheries Secretariat (Merritt, BC). xxix + 165 pp. + Appendices.

Robinson, C.K., L.A. Lapi, and E.W. Carter. 1982. Stomach contents of spiny dogfish (Squalus acanthias) caught near the Qualicum and Fraser rivers, April-May, 1980-1981. Can. MS Rep. Fish. Aquat. Sci. 1656:21 p.

Roseneau, M.L. 2014. Nearshore Habitat Utilization by Spawning Lake Char and Rearing Rainbow Trout in Shuswap, Little Shuswap and Mara Lakes (Manuscript Report for Fraser Basin Council) (pp. 1–130). British Columbia Institute of Technology Fish Wildlife and Recreation Program and rivers Institute.

Ruggerone, G.T. and B.A. Agler. 2010. AYK-Norton Sound Chinook Salmon growth and production. Arctic-Yukon-Kuskokwim Sustainable Salmon Initiative, Anchorage, AK.

Ruggerone, G.T. and J.L. Nielsen. 2009. A review of growth and survival of salmon at sea in response to competition and climate change. American Fisheries Society Symposium 70: 241–265.

Ruggerone, G.T. and J.R. Irvine. 2018. Numbers and Biomass of Natural‐and Hatchery‐Origin Pink Salmon, Chum Salmon, and Sockeye Salmon in the North Pacific Ocean, 1925–2015. Marine and Coastal Fisheries, 10(2), pp.152-168.

Ruff, C., J. Anderson, I. Kemp, N. Kendall, P. McHugh, A. Velez-Espino, C. Greene, M. Trudel, C. Holt, K. Ryding, and K. Rawson. 2017. Salish Sea Chinook salmon exhibit weaker coherence in early marine survival trends than coastal populations. Fish. Oceanogr. 26: 625-637.

Sanderson, B.L., K.A. Barnas, and M. M. Wargo Rub. 2009. Nonindigenous species of the Pacific Northwest: an overlooked risk to endangered species. Bioscience 59(3): 245-256.

Scheuerell, M.D. 2012. A hierarchical Bayesian model framework for evaluating the relative effects of environmental conditions on productivity of Chinook Salmon from the AYK region. Workshop Review Paper (unpublished working paper). In AYK SSI Chinook Salmon Synthesis Workshop, May 2-3, 2012. Arctic-Yukon-Kuskokwim Sustainable Salmon Initiative, Anchorage, AK.

Scheuerell, M.D., Zabel, R.W., and Sanford, B.P. 2009. Relating juvenile migration timing and survival to adulthood in two species of threatened Pacific salmon (Oncorhynchus spp.). Journal of Applied Ecology2 46: 983–990.

Schiefer, E., B. Menounos, and R. Wheate. 2007. Recent volume loss of British Columbia glaciers, Canada. Geophysical Research Letters 34, L16503. 6 pg.

Schindler, D., C. Krueger, P. Bisson, M. Bradford, B. Clark, J. Conitz, K. Howard, M. Jones, J. Murphy, K. Myers, M. Scheuerell, E. Volk, and J. Winton. 2013. Arctic-Yukon-Kuskokwim Chinook Salmon Research Action Plan: Evidence of Decline of Chinook Salmon Populations and Recommendations for Future Research. Prepared for the AYK Sustainable Salmon Initiative (Anchorage, AK). v + 70 pp. Available at: http://www.aykssi.org/wp-content/uploads/AYK-SSI-Chinook Salmon-Salmon-Action-Plan-83013.pdf (presently not an active link). Accessed April 8, 2014.

Scott, W.B. and E.J. Crossman. 1973. Freshwater fishes of Canada. Bull. Fish. Res. Board Can. 184:1-966.

Scrivener, J. C., T.G. Brown and B.C. Andersen. 1994. Juvenile Chinook Salmon (Oncorhynchus tshawytscha) Utilization of Hawks Creek, a Small and Nonnatal Tributary of the Upper Fraser River. Canadian Journal of Fisheries and Aquatic Sciences, 51(5), 1139–1146.

Shelton, J.M. 1955. The hatching of Chinook Salmon eggs under simulated stream conditions. Prog. Fish-Cult.95:183-187.

Snyder, J.O. 1931. Salmon of the Klamath River, California. Calif. Fish Game Fish. Bull. 34:130 p.

Stahl, K., R.D. Moore, J.M. Shea, D. Hutchinson, and A.J. Cannon. 2008. Coupled modelling of glacier and stream flow response to future climate scenarios. Water Resources Research 44 W02422: 13.

Stalberg, H.C., R.B. Lauzier, E.A. MacIsaac, M. Porter, and C. Murray. 2009. Canada's policy for conservation of wild pacific salmon: Stream, lake, and estuarine habitat indicators. Can. Man. Fish. Aquat. Sci. 2859: xiii + 135p.

Stearns, S.C. 1976. Life history tactics: a review of the ideas. Q. Rev. Biol. 51:3-47.

Stein, R.A., P.E. Reimers, and J.D. Hall. 1972. Social interaction between juvenile Coho Salmon (Oncorhynchus kisutch) and fall Chinook Salmon (O. tshawytscha) in Sixes River, Oregon. J. Fish. Res. Board Can. 29:1737-1748.

Stephen, C., T. Stitt, J. Dawson-Coates, and A. McCarthy. 2011. Assessment of the potential effects of diseases present in salmonid enhancement facilities on Fraser River Sockeye Salmon. Cohen Commission Tech. Rept. 1A: 180p. Vancouver, B.C. www.cohencommission.ca (presently not an active link).

Stephenson, S.A., 2006. A review of the occurrence of Pacific salmon (Oncorhynchus spp.) in the Canadian Western Arctic. Arctic, pp.37-46.

Su, Yu-Sung, M. Yajima. 2015. R2jags: Using R to Run 'JAGS'. R package version 0.5-7.

Sykes, G.E., C.J. Johnson, and J.M. Shrimpton. 2009. Temperature and flow effects on migration timing of Chinook Salmon smolts. Transactions of the American Fisheries Society 138: 1252-1262.

Taylor, E.B. 1988. Adaptive variation in rheotactic and agonistic behavior in newly emerged fry of Chinook Salmon, Oncorhynchus tshawytscha, from ocean- and stream-type populations. Can. J. Fish. Aquat. Sci. 45:237-243.

Taylor, E.B. 1991. Behavioural interaction and habitat use in juvenile Chinook Salmon, Oncorhynchus tshawytscha, and Coho Salmon, O. kissutch, salmon. Animal Behaviour 42(5): 729-744.

Thomas, A.C., B.W. Nelson, M.M. Lance, B.E. Deagle, and A.W. Trites. 2016. Harbour seals target juvenile salmon of conservation concern. Canadian Journal of Fisheries and Aquatic Sciences, 74(6), pp.907-921.

Tompkins, A., B. Riddell, and D.A. Nagtegaal. 2005. A Biologically-based Escapement Goal for Cowichan River Fall Chinook Salmon (Oncorhynchus tshawytscha). DFO Can. Sci. Advis. Sec. Res. Doc. 2005/095. iii + 42 p.

Trudel, M. pers. comm. 2017. Post provisional review comments. June 2017. Research Scientist, Fisheries and Oceans Canada, St. Andrews, NB.

Trudel, M. and E. Hertz. 2013. Recent advances in marine juvenile Pacific salmon research in North America. N. Pac. Anadr. Fish Comm. Tech. Rep, 9, pp.11-20.

Trudel, M., J. Fisher, J. Orsi, J.F.T. Morris, M.E. Thiess, R.M. Sweeting, S. Hinton, E. Fergusson, and D.W. Welch. 2009. Distribution and migration of juvenile Chinook Salmon derived from coded-wire tag recoveries along the continental shelf of western North America. Trans. Am. Fish. Soc.138: 1369-1391.

Trudel, M., K.R. Middleton, S. Tucker, M.E. Thiess, J.F.T. Morris, J.R. Candy, A. Mazumder, and T.D. Beacham. 2012a. Estimating winter mortality in juvenile Marble River Chinook Salmon. NPAFC Doc. 1426. 14 pp. (Available at http://www.npafc.org, presently not an active link).

Trudel, M., M.E. Thiess, S. Tucker, D. Mackas, R. Tanasichuk, S. Baillie, C. Parken, D. Dobson, and B. Peterson. 2012b. Average ocean conditions for salmon on the west coast of Vancouver Island in 2011. pp. 79-82 In Irvine, J., and Crawford, W.R. (Eds). State of physical, biological, and selected fishery resources of Pacific Canadian marine ecosystems in 2011. Canadian Science Advisory Research Document 2012/072.

Tucker, S., M. Trudel, D.W. Welch, J.R. Candy, J.F.T. Morris, M.E. Thiess, C. Wallace, and T.D. Beacham. 2011. Life history and seasonal stock-specific migration of juvenile Chinook Salmon. Trans. Am. Fish. Soc. 140:1101-1119.

Van Vleck, G.K., G. Deukmejian, and D.N. Kennedy. 1988. Water Temperature Effects on Chinook Salmon (Oncorhynchus tshawytscha) with Emphasis on the Sacramento River. A Literature Review. Prepared by G.L. Boles, Environmental Specialist IV.

Vedan, A. 2002. Traditional Okanagan environmental knowledge and fisheries management. Okanagan Nation Fisheries Commission, Westbank, B.C.

Vronskiy, B.B. 1972. Reproductive biology of the Kamchatka River Chinook Salmon (Oncorhynchus tshawytscha (Walbaum)). J. Ichthyol. 12:259-273.

Walker, P.J., and J.R. Winton. 2010. Emerging viral diseases of fish and shrimp. Veterinary Research 41: 24.

Walter, R.P., T. Aykanat, D.W. Kelly, J.M. Shrimpton and D.D. Heath. 2009. Gene flow increases temporal stability of Chinook Salmon (Oncorhynchus tshawytscha) populations in the Upper Fraser River, British Columbia, Canada. Journal of the Fisheries Board of Canada, 66(2), 167–176.

Waples, R.S., D.J. Teel, J.M. Myers, and A.R. Marshall. 2004. Life-history divergence in Chinook Salmon: historic contingency and parallel evolution. Evolution 58:386–403.

Weber, E.D., and K.D. Fausch. 2003. Interactions between hatchery and wild salmonids in streams: differences in biology and evidence for competition. Canadian Journal of Fisheries and Aquatic Science 60: 1018-1036.

Weitkamp, L. 2010. Marine distributions of Chinook Salmon from the west coast of North America determined by coded-wire tag recoveries. Trans. Am. Fish. Soc. 139: 147-170.

Wertheimer, A.C. and M.L. Dahlberg. 1983. Report of the incidence of coded-wire tagged salmonids in catches of foreign commercial and research vessels operating in the North Pacific Ocean and Bering Sea during 1982-1983. (Submitted to annual meeting International North Pacific Fisheries Commission, Anchorage, Alaska, November, 1983.) Auke Bay Laboratory, Northwest and Alaska Fisheries Center, National Marine Fisheries Service, Auke Bay, AK. 14 p.

Wertheimer A.C., W. W. Smoker, J. Maselko, and W. R. Heard. 2004. Does size matter: environmental variability, adult size, and survival of wild and hatchery Pink Salmon in Prince William Sound, Alaska. Reviews in Fish Biology and Fisheries 14(3): 321-334.

Westley, P., pers. comm. 2017. Post provisional review comments. June 2017. Assistant Professor of Fisheries, University of Alaska, COSEWIC Marine Fishes SSC Member, Anchorage, AK.

Westley, P.A., T.P. Quinn, and A.H. Dittman. 2013. Rates of straying by hatchery-produced Pacific salmon (Oncorhynchus spp.) and steelhead (Oncorhynchus mykiss) differ among species, life history types, and populations. Canadian Journal of Fisheries and Aquatic Sciences, 70(5), pp.735-746.

Williams, G.L. 1989. Coastal/Estuarine fish habitat description and assessment manual. Part I. Species/Habitat outlines. Prepared for DFO by G.L. Williams and Associates.

Withler, R.E., Bradford, M.J., Willis, D.M., and Holt, C. 2018. Genetically Based Targets for Enhanced Contributions to Canadian Pacific Chinook Salmon Populations. Department of Fisheries and Oceans Canadian Science Advisory Secretariat Research Document 2018/019. xii + 88 p.

Yancey, R.M. and F.V. Thorsteinson. 1963. The king salmon of Cook Inlet Alaska, U.S. Fish Wildl. Serv. Spec. Sci. Rep. Fish. 440:18 p.

Yates, D., H. Galbraith, D. Purkey, A. Huber-Lee, J. Sieber, J. West, S. Herrod-Julius, and B. Joyce. 2008. Climate warming, water storage, and Chinook Salmon in California's Sacramento Valley. Climate Change 91(304):335-350.

Yurk, H. and A.W. Trites. 2000. Experimental attempts to reduce predation by harbor seals on out-migrating juvenile salmonids. Transactions of the American Fisheries Society 129: 1360-1366.

Zimmerman, M.S., J.R. Irvine, M. O'Neill, J.H. Anderson, C.M. Greene, J. Weinheimer, M. Trudel, and K. Rawson. 2015. Smolt survival patterns of wild and hatchery Coho Salmon in the Salish Sea. Mar. Coast. Fish. 7: 116-134.

Biographical summary of report writers

Dr. Brian O. Ma and Cedar Morton are Senior Systems Ecologists at ESSA Technologies Ltd. in Vancouver BC. Diana Abraham is a researcher and science writer previously of ESSA Technologies Ltd., with over 20 years of experience.

• Previous page
• Table of contents
• Next page