Grass Pickerel (Esox americanus vermiculatus): report on the progress of management plan implementation for the period 2017 to 2022

Protocol development: develop consistent protocols for surveying and monitoring Grass Pickerel populations, including the collection of genetic material, should genetic analysis be required

As the species is infrequently the principal target of surveys, a long-term sampling protocol has not been fully developed at this time. Nonetheless, refinement of fish sampling protocols continues, and can be applicable to the capture of Grass Pickerel.

Hernandez et al. (2020) developed qPCR primers and probes in order to monitor a variety of invasive, threatened, and exploited aquatic species, including Grass Pickerel. As environmental DNA (eDNA) is increasingly used to detect species at risk, the results of this study will aid in the detection of Grass Pickerel.

Gardner Costa et al. (2020) appraised the sampling efficacy of passive gear in Phragmites stands in the St. Clair River delta. Fyke nets (compared to large- and small-mesh gill nets, and Windermere traps) were found to be most effective for sampling the fish assemblage in Phragmites stands. Additionally, 4 Grass Pickerel were captured during this assessment in the St. Clair River delta in 2017.

Colm et al. (2020) developed an age–length key that could be used as a non-lethal proxy method for assessing the general age structure of Canadian Grass Pickerel populations. Additionally, it was determined that scales were not reliable for age estimation in Grass Pickerel, as they tended to underestimate age compared to age estimates based on cleithra.

The Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs (MELCCFP) is in the process of finalizing a global and standardized protocol for the capture of small fish, which includes Grass Pickerel.

Over the 2017 to 2022 time period, targeted sampling for Grass Pickerel was conducted by DFO in L Lake (Barnucz and Drake 2021). The goal of the study was to determine the utility of depletion seining and mark-recapture sampling to estimate population size, distribution, and habitat features of Grass Pickerel (and Lake Chubsucker, Erimyzon sucetta) in L Lake. A total of 15 Grass Pickerel were captured from 43 sites that were visited twice, in August and September 2018.

In 2019, surveys targeting Grass Pickerel were undertaken in Point Pelee National Park (Barnucz et al. 2021). A total of 6 Grass Pickerel were captured with detections in each of the 3 waterbodies surveyed, which included East and West Cranberry Ponds, and Lake Pond. Similar surveys were conducted in 2021 in Girardin Pond, Redhead Pond, and Lake Pond (Barnucz et al. 2022). In Redhead Pond, 2 Grass Pickerel were captured.

DFO conducted non-targeted sampling in which Grass Pickerel were captured, including in the Ausable River (close to the Old Ausable Channel) (1 individual in 2017); in Goose Lake of the Walpole Island marshes (1 individual); in Chenail Ecarte/the Snye (3, 4, and 1 individuals in 2017, 2018 and 2020, respectively); in Running Creek, which drains into Chenail Ecarte, (1 individual in 2017); the Detroit River (2 individuals captured in 2017 and 1 individual was captured in 2021); McLean Drain, which drains into the Canard River (2 individuals); Long Point Inner Bay (50 individuals) and Turkey Point (3 individuals); and in Presqu’ile Bay (5 individuals).

A total of 231 Grass Pickerel were detected in Ontario by external agencies in numerous waterbodies, including Long Point Bay, Hahn Marsh (Big Creek National Wildlife Area [NWA]), Lake St. Clair, St. Lawrence River (Thousand Islands Region), Maxwell Creek and the connecting Prince Albert Drain, Steen Peterkin Drain (which drains into Rankin Creek), Collop Drain, Old Ausable Channel, Niagara River, and L-Lake.

Additionally, reports have recently been published that characterize surveys that occurred in the time-period of the previous progress report (2012 to 2017). During a nearshore fish community assessment of the upper and lower Niagara River (2015 to 2017), 2 Grass Pickerel were captured near the mouth of Ussher’s Creek in 2015 (Gáspárdy et al. 2020). Finigan et al. (2018) captured 4 Grass Pickerel (2014) in Gananoque Lake during a historical fish community assessment of lakes in southeastern Ontario.

Sampling surveys using a surface trawl were conducted in Presqu’ile Bay and West Lake (Prince Edward County) by OMNRF in 2021; however, Grass Pickerel was not detected (LeBaron and Reid 2023). The OMNRF conducted additional surface trawl surveys in 2022 in coastal wetlands of the Bay of Quinte and Prince Edward County, including Presqu’ile Bay; however, no Grass Pickerel were detected (LeBaron et al. 2023).

Understanding of the distribution of the species continues to be improved in localities where it has been routinely captured, such as the St. Lawrence River (Thousand Islands Region), and the Lake St. Clair watershed. This increased understanding of the occurrence of this species is largely attributable to fish community surveys, many of which have habitat that may be suitable for Grass Pickerel.

Additionally, sampling continues to occur in historic localities with suitable sampling gear (that is, electrofishing, fyke and seine nets) that has the potential to rediscover the species (for example, Belle River, Duck and Pike creeks, East Sydenham River, Cooper’s Marsh in Lake St. Francis, and the Grand River watershed).

In Ontario, no targeted sampling has been conducted for Grass Pickerel in high-probability novel areas between 2017 and 2022. However, Colm et al. (2019) conducted research to examine habitat variables that explain the distribution of Grass Pickerel, which included sampling novel areas where the species is not known to occur that are hydrologically connected to occupied localities and contain suitable habitat features, including Bass Lake, Buck Lake, Elbe Creek, Gananoque River, Gartersnake Creek, Graham Lake, Grass Lake, Grippen Creek, Hoaglands Marsh, Lambs Pond, Leeders Creek, North Wiltse Creek, Sparrow Lake, Sunny Lake, and Temperance Lake. Of these localities, Grass Pickerel was detected at Bass Lake (1 individual), Graham Lake (3 individuals), Grass Lake (5 individuals), and Leeders Creek (1 individual). Although these sampling surveys were completed in 2014, the results of this research were published in 2019.

Furthermore, Grass Pickerel continues to be detected through non-targeted fish community surveys and other research activities. For example, Grass Pickerel were detected in Running Creek (tributary to the Snye) in 2017 (Midwood et al. 2020), in new localities within the Detroit River at Peche Island in 2017 (Midwood et al. 2020), and at a small bay by Petite Cote Conservation Area across from Fighting Island in 2021 during routine Asian carp monitoring. In the course of classifying municipal drains, the St. Clair Region Conservation Authority (SCRCA) captured Grass Pickerel for the first time in the Steen Peterkin and Collop drains.

Although many regular fish community surveys are performed in areas known to contain Grass Pickerel, the species is not actively targeted.

In Quebec, the Réseau de suivi ichtyologique (RSI), operated by the MELCCFP, monitors species present in the St. Lawrence River, including Lake St. Francis and Lake St. Louis. Grass Pickerel have never been captured through this network’s sampling campaigns. The likelihood of the species being detected by the network is probably low, as it does not cover small streams, which the species seems to prefer; however, it could be captured if it were present in Lake Saint-François since some seine sampling stations are located near the shore.

DFO continues to undertake invasive species risk assessments (for example, Mandrak et al. 2020) and ongoing surveillance for Asian carps within the Great Lakes. In addition to monitoring for aquatic invasive species that may negatively impact Grass Pickerel or its habitat, the Asian carp monitoring surveys often capture Grass Pickerel, and hence, aid in the understanding of their distribution and abundance.

Morrison and Moore (2017) documented the first juvenile Chain Pickerel captured in Ontario waters of Lake Ontario (Port of Newcastle). The specimen was captured as a result of annual monitoring surveys undertaken by The Central Lake Ontario Conservation Authority (CLOCA) as part of their Durham Region Coastal Wetland Monitoring Program. Similar surveys are conducted in the Bay of Quinte as part of the Bay of Quinte Remedial Action Plan. Both survey programs may continue to contribute to understanding of Chain Pickerel distribution in the Lake Ontario watershed.

In Quebec MELCCFP monitors for invasive species through targeted surveys, and “opportunistic” non-target sampling projects.

Collaboration with existing ecosystem recovery teams such as the Ontario Freshwater Fish Recovery Team and Équipe de rétablissement des cyprins et petits percidés du Québec continues to be important in successful implementation of conservation measures.

Information regarding Grass Pickerel conservation continues to be provided to key stakeholders (for example, Ontario Land Trust Alliance, students of the Fleming College heavy equipment operators course, Drains Action Working Group) and Indigenous groups during outreach meetings. Many conservation measures have been implemented jointly with other organizations, including the CAs and the OMNRF, as well as a number of academic partners.

In Quebec, discussions have been initiated between DFO and Environment and Climate Change Canada (ECCC) regarding the Lake Saint-François NWA to facilitate implementation of beneficial management measures for the Grass Pickerel.

Glass et al. (2021) investigated the impacts of drain maintenance and reconstruction activities on Grass Pickerel in Beaver Creek. They concluded that monitoring for at least 3 years prior to the drainage works, along with post-project monitoring of at least 4 years, was required to determine the effects of drainage activities on Grass Pickerel.

Montgomery et al. (2018) developed a predictive habitat-based framework to assess the effects of drain maintenance on imperiled fishes. Their framework can be used to identify and mitigate potential risks of maintenance activities to fish, including Grass Pickerel.

Mitigation measures are recommended based on DFO’s “Updated Review Considerations and Mitigation Guide for Habitat of the Grass Pickerel ” (Coker et al. 2021). The mitigation strategies focus on minimizing the impact of watercourse modifications related to agricultural drainage works on Grass Pickerel.

No progress has been made on this conservation measure.

A central database was developed that includes all historical and current reports of captured Grass Pickerel and 4 other at risk fish species (see Couillard et al. 2013).

MELCCFP maintains catch data for all fish species. The data of the most precarious species (including the Grass Pickerel) are imported into the Centre de Données sur le Patrimoine Naturel du Québec (CDPNQ) to track species distribution and occurrence. These species occurrence records are then available to the clientele of the CDPNQ and the MELCCFP.

Although patterns of Grass Pickerel distribution have been related to habitat characteristics (Colm et al. 2019), no research has been conducted in the last 5 years that characterizes the seasonal habitat requirements of Grass Pickerel at various life stages. Furthermore, research by Colm and Mandrak (2021) suggests that observed differences in Grass Pickerel abundance between sites may be life-stage dependent.

Sufficient data has yet to be generated to ascertain the population dynamics of Grass Pickerel at Canadian locales. Ongoing research should aid in fulfilling this goal.

DFO has conducted extensive sampling of Grass Pickerel in Beaver Creek (Niagara Region), which has helped to characterize demographic traits and abundance trends. Fluctuations in Grass Pickerel abundance have been related to variable environmental conditions (Colm et al. 2020; Colm and Mandrak 2021). The authors of both studies postulated that high density may have limited growth rates and resulted in increased mortality, while a decline in abundance was also related to drought conditions.

Malcolm (2015)^c made an initial attempt to estimate the minimum area for a viable population (MAVP) of Grass Pickerel in both flowing (~50,000 to 200,000 m²) and standing water environments (~170,000 to 690,000 m²); however, additional research is required to refine the estimates and to determine habitat quality requirements.

DFO has conducted preliminary modelling exercises to estimate Grass Pickerel minimum viable population size (MVP) and minimum area of population viability (MAPV) using data from Beaver Creek (DFO 2021). The MVP was estimated at 1,653 (age 3+) with a corresponding MAPV estimated at 14,853 m² of age 1+ fish habitat, 4,921 m2 of young-of-year habitat and 7,992 m2 of spawning habitat.

Colm et al. (2019) investigated patterns in Grass Pickerel distribution in relation to a variety of habitat variables and the fish community assemblage. Grass Pickerel were more likely to be found at sites that had relatively high conductivity, channel cover and wetlands in the floodplain, and gentle sloping banks. In contrast, they found that Grass Pickerel was absent from areas with moderate to high baseflow and reach slopes. Overall, habitat features at the site-scale appeared more important than reach-scale in explaining distribution patterns of the species.

During the time period of this progress report, research has been initiated at the University of Toronto (U of T) that may lead to the examination of the movement ecology of adult Grass Pickerel, which is a step towards understanding quantity and quality of habitat required to ensure long-term conservation of Grass Pickerel (Drake pers. comm. 2022).

Montgomery et al. (2020) investigated the extinction debt of fish in Lake Erie wetlands. Extinction debt is referring to a time lag between habitat loss and local extinction. Fourteen wetlands containing Grass Pickerel were identified as being in extinction debt for the species due to habitat alteration and, hence, are in need of restoration.

Ziegler et al. (2021) investigated temperature-induced hypoxic stress on 3 fish species at risk (including Grass Pickerel) using ecosystem metabolism models. The Old Ausable Channel was the system under consideration, which is a low-flow, fragmented river system. Hypoxic conditions were observed both during the winter months when ice was present, as well as the summer months. River fragmentation and climate change were identified as potential drivers of hypoxic stress. The authors present recovery measures that are likely to reduce hypoxic stress, namely, the restoration of turbulent mixing, planting of riparian vegetation, and reducing warm stormwater run-off from urban areas.

A decline in abundance of Grass Pickerel in a municipal drain (Beaver Creek, Niagara Region) may have been related to drought conditions (Colm and Mandrak 2021), which as a result of climate change, may become more common and extreme. It appears that the creation of deeper pools during drain maintenance and reconstruction may be important in mitigating the effects of drought on Grass Pickerel (DFO 2021).

Croft-White et al. (2021) demonstrated an alteration of a wetland fish assemblage towards a centrarchid-dominated community in areas that have become dominated by Phragmites. Impacts specific to Grass Pickerel remain to be investigated.

Coker et al. (2021) assembled an updated list of threats to Grass Pickerel habitat in relation to watercourse modifications, along with a description of mechanisms of potential impact.

In response to control efforts to manage the establishment of European Common Reed in Lake Erie’s coastal wetlands (that is, Rondeau Provincial Park, Long Point Crown Marsh, Big Creek NWA and Long Point NWA), OMNRF carried out a monitoring project to evaluate the effects of the herbicide application and to evaluate the benefits of invasive species removal to fish SAR (Reid et al. 2023). Visual-based surveys of fish were completed before and after herbicide application at Long Point and Rondeau Provincial Park from 2016 to 2020, and a before-after-control-impact (BACI) monitoring program was initiated in 2020 for Big Creek Unit of Big Creek NWA and Thoroughfare Unit of Long Point NWA, recording the number of distressed or dead fish between treatment and control sites. Researchers found no evidence of elevated mortality risk from aerial herbicide application in Big Creek NWA and Rondeau Provincial Park. The level of fish mortality varied among ponds in the Crown Marsh treatment areas, with smaller and more isolated ponds displaying higher mortality than others (Reid et al. 2023). No dead Grass Pickerel were detected.

Glass et al. (2021) conducted a series of before-after-control-impact (BACI) analyses to determine the effect of drain maintenance and reconstruction activities on Grass Pickerel in Beaver Creek. Although some of the potential negative effects of drain maintenance were observed (higher conductivity, higher water temperature, loss of vegetation), results of this study indicate that reconstruction incorporating natural stream channel design features had a positive impact on Grass Pickerel. Additionally, the authors determined that a substantial time period of monitoring is required pre- and post-drain maintenance to confidently determine the effects of drainage activities.

Coker et al. (2021) catalogued the potential mechanisms of harm to Grass Pickerel in relation to drain maintenance activities. Briefly, drainage activities can disconnect waterbodies, remove aquatic vegetation and woody debris, and reduce still-water habitats.

Population genetic structure was assessed for Grass Pickerel in Ontario and Quebec over 12 geographic localities (DFO 2017). More recently Lujan et al. (2022) quantified genomic diversity within and among Canadian populations of Grass Pickerel to characterize population structure and to inform future COSEWIC assessments investigating the potential need to split the population into separate designatable units. They analyzed tissue samples from localities including Kahshe Lake, Old Ausable Channel, L-Lake, Little Bear Creek, Hahn Marsh, Long Point Bay, Big Forks Creek, Tea Creek, Lyon's Creek, Abino Drain, Twenty Mile Creek, West Lake, Jones Creek, Rivière aux Saumons, Chenaux Lac-Saint-Francois, Ruisseau McMillan, and Ruisseau sans nom. The results of this study indicate that there is significant geographical population structure, with 4 distinct genomic clusters evident, distinguishing populations found in the Georgian Bay-Severn River area, the southeastern shore of Lake Huron, the Niagara Peninsula, and the Upper St. Lawrence River. Furthermore, Lujan et al. (2022) found that there were sub-clusters within the Niagara Peninsula, including Abino Drain, Big Forks Creek, and Tea Creek.

Community support has been raised through DFO outreach efforts that have improved the coordination of recovery efforts and have fostered partnerships. Applicable events include the annual meeting of the Stewardship and Outreach Recovery Implementation Group, and the delivery of presentations to Indigenous groups, the Ontario Aboriginal Lands Association (OALA), and the Ontario First Nations Economic Development Association (OFNEDA) regarding threats to aquatic species at risk and protection measures that can be implemented to reduce risk within their areas.

Environment and Climate Change Canada (ECCC) has continued to coordinate stewardship initiatives in National Wildlife Areas (NWA) during this time period, including funding habitat improvement projects with multiple partners in the Long Point region through the Priority Place Funding Program. For example, extensive control programs to manage Phragmites, an invasive plant species estimated to cover more than 1,500 ha of the region’s wetlands and coastal areas, have been undertaken in Long Point and Big Creek NWAs and ponds and channels have been created to improve habitat in Big Creek NWA. To date, more than 1,400 ha of Phragmites has been managed, resulting in enhanced fish habitat and improved wetland habitat through the re-establishment of native vegetation.

The Province of Ontario recently supported the development of Invasive Phragmites Best Management Practices (2021) geared specifically to improving species at risk habitat through the management of invasive Phragmites.

In Ontario, between 2017 and 2022, DFO met face-to-face and provided web-based training to over 4,000 members of communities, stakeholder groups, and partner agencies. Outreach promoting species protection, conservation, and stewardship has also included the promotion and distribution of DFO aquatic species at risk Official Plan guidance, and species at risk distribution maps for project proponents to screen for presence of aquatic species at risk to avoid project impacts.

In Quebec, discussions on possibilities of conservation projects have been initiated between DFO and the Haut-Saint-Laurent ZIP committee, the Mohawk Council of Akwesasne (MCA) and members of l’Équipe de rétablissement des cyprins et des petits percidés du Québec.

Federal funding is available annually through the Aboriginal Fund for Species at Risk (AFSAR), the Habitat Stewardship Program (HSP), and the Canada Nature Fund for Aquatic Species at Risk (CNFASAR). HSP funding is provided by DFO to CAs and ENGOs to support local stewardship initiatives, while AFSAR funding supports the development of Indigenous capacity to participate actively in the implementation of SARA. CNFASAR is aimed at supporting stewardship projects that help recover and protect aquatic species at risk. Collectively, the activities supported through this program facilitate the implementation of conservation measures, such as BMPs associated with water quality improvements, and sediment loading and reduction.

The Ausable Bayfield Conservation Authority (ABCA) has promoted funding opportunities for stewardship activities via flyers, newspaper articles, media releases, and direct engagement. ABCA sent out stewardship postcards to engage landowners and to inform them that CNFASAR is providing incentives for stewardship. With the aid of CNFASAR funding, the ABCA and Ontario Streams worked in collaboration with a neighborhood group that borders the Old Ausable Channel to implement natural channel design principles on a section of eroded bank, which will help to restore the shoreline and reduce sediment and nutrients inputs. The ABCA have conducted outreach events to educate targeted landowners on species at risk and to promote stewardship opportunities. Additionally, they have developed and implemented an ongoing habitat monitoring program in the Old Ausable Channel to look at water levels, dissolved oxygen, and nutrients.

Similarly, MECP administers the Species at Risk Stewardship Program (SARSP), which provides funding for similar stewardship activities as described for the HSP. Some of the projects funded through SARSP have been conducted in areas where Grass Pickerel occurs, including activities undertaken by ABCA.

Through partnerships with watershed-based conservation organizations (CAs in Ontario), DFO staff have promoted the implementation of BMPs via presentations, project reviews, and site meetings with the agricultural community, drainage engineers, and the Ontario Drainage Superintendents Association.

The use of BMPs is encouraged through project reviews and mitigation on rural properties, including livestock restrictions (exclusion fencing); milkhouse washwater system installations; riparian buffers; streambank stabilization; wetland creation or enhancement; well decommissioning; septic upgrades; and sediment control/trapping to prevent run-off and improve water quality.

The Species at Risk Farm Incentive Program , through the Ontario Soil and Crop Improvement Association (OSCIA), includes information on what agricultural BMPs can help species at risk, including information on cost-share opportunities. Completed projects have resulted in streambank protection and enhancement (for example, riparian buffer plantings, erosion control work, exclusionary fencing for livestock) and wetland restoration. This program receives funding from HSP and SARSP.

The Great Lakes Agricultural Stewardship Initiative, targeting the Lake Erie basin and the southeast shores of Lake Huron, aided farmers in adopting BMPs regarding soil erosion control structures, cover crops, residue management, and buffer and shelter strips.

The HSP and SARSP provide support for local stewardship initiatives led by CAs and ENGOs. Access to these funding programs has resulted in a number of habitat improvement projects. For example, the Essex Region Conservation Authority (ERCA) has enhanced fish habitat by improving riparian habitat, creating new wetlands, and stabilizing erodible lands and actively eroding streambanks on agricultural lands. The ABCA has aided in cover crop planting, and restoring wetlands and riparian habitats at multiple sites. Taken together, these projects enhance water quality conditions and aquatic habitat for Grass Pickerel along with other species at risk, and other associated aquatic species.

In Quebec, Ambioterra started a project in 2018 to protect and restore Grass Pickerel in 4 tributaries of Lake St. Francis where DFO recently (2014 to 2016) discovered the species for the first time.

In Ontario, partner agencies (CAs and MECP) continue to promote retirement of fragile lands through various land and water management and stewardship programs as well as BMPs.

Ongoing DFO outreach to Indigenous communities, key stakeholders, and the Canadian public, includes information on Grass Pickerel, helping to raise awareness of its status and need for conservation. For example, DFO has constructed and disseminated individual species infographics, including 1 for the Grass Pickerel. As a result of the COVID-19 pandemic, outreach has shifted to presentations on web-based communication platforms. DFO, in conjunction with CAs, has reached representatives from municipalities, consultants, and contractors with presentations on SARA, aquatic species at risk listing changes, funding opportunities, and highlighted CA stewardship successes.

The ABCA, with funding from HSP and SARSP, has conducted community information sessions and student programs to educate and increase the profile of species at risk in the Ausable River watershed. Furthermore, the River Institute has increased the profile of the Grass Pickerel through social media posts.

Municipal public works and planning departments, municipal drainage superintendents, and drainage engineers have been included in aquatic species at risk outreach activities conducted by DFO, that include reference to threats and mitigation that can be applied to conserve Grass Pickerel. DFO has developed and distributed aquatic species at risk guidance for municipalities to incorporate into municipal official plan updates.

As mentioned, mitigation measures are recommended to proponents based on DFO’s “Updated Review Considerations and Mitigation Guide for Habitat of the Grass Pickerel ” (Coker et al. 2021).

Aquatic Species at Risk fact sheets for Grass Pickerel, including general description, distribution, habitat, life history, diet, threats, and similar species information (noting distinguishing features) were developed by DFO. These fact sheets have been disseminated at a variety of outreach events and trade shows and are available to watershed landowners through various conservation authority offices across their range. Species profile information for Grass Pickerel is also available on the Species at Risk Public Registry and on DFO’s Aquatic Species at Risk website .

CAs and MECP may promote retirement of fragile lands (for example, wetlands) through stewardship, land and water management, and rural water-quality improvement programs.

The Government of Canada’s Species at Risk Public Registry promotes funding and support for species at risk. Grants and incentive programs are also promoted through provincial programs, including the Ontario Managed Forest Tax Incentive Program and the Ontario Conservation Land Tax Incentive Program . In both Ontario and Quebec, there is Canada’s Ecological Gifts Program .