Management Plan for the Banded Killifish, Newfoundland Population, in Canada [Final] 2011: Threats

Table 1 summarizes all known and suspected threats to the Banded Killifish, Newfoundland population. Assessment of threats allows for prioritization of recommended management and other actions to prevent this population from becoming threatened or endangered, and provides an indication of the feasibility for mitigation of a threat. Definitions of the terms used in the threat classification table are available in Appendix 1. It should be noted that although some activities may occur on a local basis, the specific threat associated may also have influence range-wide (relating to the whole distribution or a large portion of the range of the species). Further information related to the threats, stresses and mitigation measures is provided in Section 1.5.2 and Section 2.3.

Table 1. Threat Classification Table

COSEWIC (2003) identified potential forestry impacts as a primary anthropogenic threat to Banded Killifish in Newfoundland. While little in the way of forest harvesting is currently occurring on the south and southwest coasts in the areas around Banded Killifish locations, much of the area surrounding several lakes in the Indian Bay watershed was scheduled for clear cutting (Chippett, 2003). Such activities (including associated forest road construction), if not properly mitigated, have the potential to increase suspended sediment loads in adjacent waterbodies. Associated impacts of increased suspended sediment include reductions in invertebrate abundances, decreased feeding success for sight-feeding species, and dislocation and mortality of early life stages (Miller, 1981). Sediments can suffocate aquatic vegetation, thus decreasing primary production (Waters, 1995). Suspended sediments can also damage fish gills causing injury, mortality and increased susceptibility to disease and predation (Gosse et. al., 1998). Desgagne and Lalancette (1984) indicated that Banded Killifish forage based on visual perception, while Richardson (1939) stated that this species makes use of aquatic vegetation in their reproductive cycle. As such, forestry activities that result in increased sedimentation in adjacent waterbodies may have a negative impact on Banded Killifish if not properly mitigated. In the Indian Bay watershed, substantial buffers have been established on most of the watershed and lakes of primary Banded Killifish locations have 500m-1km buffers (Blair Adams, Regional Ecologist, Department of Natural Resources, Pers. Comm.).

Banded Killifish are rarely found in first and second order streams (even those with a low to moderate gradient) and the interaction between forest harvest activities and aquatic ecosystems occurs primarily in first to third order streams. Thus, most forest harvest activities in the province of Newfoundland and Labrador do not interact with Banded Killifish habitat (Blair Adams, Regional Ecologist, Department of Natural Resources, Pers. Comm.). The limited short-term studies of forest harvest activities, as practiced in the province of Newfoundland and Labrador, indicate that these activities do not seem to create a sustained change in water quality (Scruton et al., 1995; Wells, 2002). Existing buffer zone guidelines as specified in Environmental Protection Plans and DFO habitat policy help ensure that any aquatic impacts are minimal and short-term (Blair Adams, Regional Ecologist, Department of Natural Resources, Pers. Comm.).

Many land use activities have the potential to negatively impact Banded Killifish habitat. These include road developments (especially those that involve watercourse crossings), mineral exploration and urban/cabin development. Such activities can result in direct habitat destruction, increased sedimentation, contamination, altered water flow regimes and impediments to migration, if not properly mitigated.

A potential, yet unquantified, threat to this species includes recreational fishing, which may impact the population through direct catches or use as bait. However, this threat is not considered to be significant. Banded Killifish are also caught as by-catch in commercial American Eel fisheries, particularly in southwest Newfoundland (Derek Tobin, Resource Management, DFO, Newfoundland and Labrador Region, Pers. Comm.). In 2006, the Mi'kmaq Alsumk Mowimsikik Koqoey Association (MAMKA) attempted to quantify this threat for both eel fyke nets and baited eel pots in the Bay St. George region. While this research confirmed that Banded Killifish are a common by-catch species in the commercial Eel fishery, observed mortality for the species was below 1%. As such, MAMKA (2006) concluded that the Eel fishery did not pose a major threat to the conservation of Banded Killifish.

The presence of two invasive predator species, i.e. the Brown Trout (Salmo trutta) and Rainbow Trout (Onchoryncus mykiss), has been documented and these species appear to be expanding their distributions (Brown Trout on the east coast and Rainbow Trout on the west coast) (Van Zyll de Jong et al. 2004; Westley et al. 2007). Both species make heavy use of estuarine habitat during anadromous migrations and may have an impact on Banded Killifish in brackish and freshwater areas. The presence of these species represents a permanent change to the ecosystem (Blair Adams, Regional Ecologist, Department of Natural Resources, Pers. Comm.).

The only focused monitoring program for Banded Killifish in Newfoundland was initiated by the Government of Newfoundland and Labrador Wildlife Division in 1994, and was conducted in partnership with Memorial University of Newfoundland and the Indian Bay Ecosystem Corporation. These efforts produced an indication of Banded Killifish presence and some critical information on habitat and distribution. In 1998, these same three organizations partnered to support a graduate research project, which applied a more intensive sampling program to provide necessary information to answer several key questions concerning the biology of all Newfoundland populations. Details regarding the methodology and results of this research are outlined in Chippett (2004).

Chippett (2003) documented locations of Banded Killifish in Newfoundland (Appendix 3, Fig. 1). However, recent findings suggest a more extensive distribution. Banded Killifish surveys carried out by MAMKA in Bay St. George during 2006 identified additional sites where Banded Killifish were present (MAMKA, 2006). While many of these sites may be considered part of a single catchment, these surveys suggest a wider distribution than that previously documented. MAMKA (2010) also reports further findings of Banded Killifish in the Bay St. George's area as well as the Bay of Islands and Exploits Bay areas.

In 2006, Banded Killifish were identified in coastal lagoons near the community of York Harbour, in the Bay of Islands (Derek Osborne, SARA Coordinator, DFO, Newfoundland and Labrador Region, Pers. Comm.). Photos and samples support the presence of additional locations in both Garnish Pond (Jerry Walsh, Chief of NAFO Compliance and Offshore Operations, DFO, Newfoundland and Labrador Region, Pers. Comm.) and Spanish Room (Laura Park, Oceans Biologist, DFO, Newfoundland and Labrador Region, Pers. Comm.) on the Burin Peninsula. Anecdotal information also suggests potential sites in the Main Brook area on the Great Northern Peninsula, First Pond in the Port aux Basques region and Star Lake in Central Newfoundland (Chippett, 2004). Banded Killifish have also been reported from Burton's Pond in St. John's and are likely an introduced population (Chuck Bourgeois, Section Head, Salmonids, DFO, Newfoundland and Labrador Region, Pers. Comm.) Further surveys throughout the island may reveal other previously undocumented locations.

Fish surveys carried out in Notre Dame and Beothuk Provincial Parks, various sites on the Avalon Peninsula (including the Winterton and Hants Harbour areas), Mint Brook (Gambo), various lakes in Gros Morne and Terra Nova National Parks, Millertown, Main Brook and several additional lakes in the Indian Bay Watershed did not result in any observations of Banded Killifish (Chippett, 2004).

Chippett (2003) noted anecdotal evidence which suggests that the Banded Killifish located in the Indian Bay watershed may be the result of an introduction by anglers using Banded Killifish as bait. Indeed, anglers from the Maritime Provinces using "minnows" as live bait have traditionally fished in Backup and Third Ponds, where Banded Killifish have been recorded. While this may be impossible to substantiate, this potential introduction may explain the presence of a disjunct location in the northeast.