Fish Spawning and Loon Nesting Activities on Jack Lake and Potential Impacts of Artificial Water Level Fluctuations

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1 Fish Spawning and Loon Nesting Activities on Jack Lake and Potential Impacts of Artificial Water Level Fluctuations May 2014 Prepared for the Jack Lake Association by Steven J. Kerr

2 Introduction Jack Lake ( ) is one of a series of headwater lakes whose catchment is used to provide water for the Trent-Severn Waterway (TSW). Lake levels are artificially controlled by a dam at the lake outlet. Ill-timed or excessive artificial water level fluctuations can have a number of ecological impacts on lake biota including a reduction in abundance of benthic macroinvertebrates, dewatered wetlands, as well as a disruption to waterfowl nesting and fish spawning activities (see review by Leira and Cantonati 2008). Generally, biological effects are most severe in shallow water and littoral areas of a lake. Artificial drawdowns of lake water levels has been identified as an issue on Jack Lake. It has been recommended that Parks Canada staff be made aware of negative ecological impacts associated with their water control operation (Jack Lake Association Fisheries Committee 2013). This paper has been prepared to consolidate and summarize information on various fish spawning and loon nesting activities on Jack Lake in the hopes that it may be used to mitigate harmful impacts associated with the current water level management regime. Fish Spawning Activities Muskellunge Muskellunge spawn in the spring at water temperatures ranging from C. They utilize shallow wetlands commonly having logs, aquatic vegetation and detritus substrate. Muskellunge spawning sites in Jack Lake range in depth from meter in depth (Allan 1989). As such they are extremely vulnerable to any significant fluctuations in water levels. The only muskellunge spawning survey conducted on Jack Lake was completed in 1986 (Dosser 1987). That year, peak spawning activity occurred from April and had concluded by early May. In Rathbun Bay, post-spawn muskellunge are often observed during the Victoria Day weekend in May (S. Kerr personal observation). Future efforts should be directed at more extensive documentation of muskellunge spawning activity in Jack Lake. Walleye Walleye are also spring spawners. Spawning occurs at water temperatures ranging from 5-13 C. In some instances, spawning can occur on ice-free shorelines while ice is still present on the lake (Allan 1989). Walleye actively select shallow nearshore waters to spawn (Kerr et al. 1997, Raabe and Bozek 2012). Allan (1989) found that Jack Lake walleye spawned at depths of meters. In Apsley Creek, walleye were found to spawn at depths ranging from cm in depth (Corbett and Powles 1986). In Jack Lake walleye spawn in two small tributaries (Apsley and Redmond Creeks) as well as numerous shoals in the lake. Several efforts by the Ontario Ministry of Natural Resources

3 (MNR) and the Jack Lake Association (JLA) have served to create new shoals and enlarge existing shoals in Jack Lake in recent years. Water levels lowered after spawning can result in dewatering of spawning grounds and dessication of sedentary incubating eggs (Kerr et al. 1997). Colby et al (1979) concluded that fluctuating water levels was a major factor determining year class strength in walleye. Fortunately, there have been several walleye spawning surveys conducted on Jack Lake over the years (Table 1) which document spawning dates in the lake. Table 1. Walleye spawning observations in Jack Lake, Peterborough County. Walleye Spawning Activity Year Ice Out Date Start Peak Finish Source April 11 April April 23 Corbett (1981), Corbett and Powles (1986) April Dosser (1987) April 5 April late April Dosser and Brisbane (1989) April JLA Walleye Watch late April JLA Walleye Watch April JLA Walleye Watch 2010 March 31 (early spring) - April JLA Walleye Watch 2011 April 17 - April 21 - JLA Walleye Watch After a review of the potential impacts of artificial water level fluctuations on walleye, Kerr et al. (2004) recommended that natural water cycles be mimicked, namely stable or rising water levels during spawning and incubation, water level reductions during mid to late summer and stable water levels during fall and winter. Lake Trout Lake trout are fall spawners. They select wind-exposed shoals in shallow water. Based on a survey of 234 spawning sites on 90 Ontario lake trout lakes, the mean depth of spawning shoal ranged from 0.1 to 6.0 meters (average depth of 1.4 meter) (Legault et al.2004). Improperly timed drawdowns can expose spawning substrate thereby causing extensive egg mortality at those sites. In addition, drawdowns may also have similar impacts on lake herring (also fall spawners) which could, in turn, reduce the size of the forage base for lake trout. Only one lake trout spawning survey has been undertaken on Jack Lake. In 2008 it was found that lake trout spawning activity had peaked from October and was completed by the end of October (Plunkett et al. 2009). More comprehensive efforts are required to document lake trout spawning activity in Jack Lake.

4 After a provincial review of lake trout in Ontario, it was recommended that artificial drawdowns should be completed before the start of the lake trout spawning season and that overwinter drawdowns should be prohibited (Olver et al. 1991). Loon Nesting Activities The common loon (Gavia immer) migrates south in the autumn and returns in the spring. Spring arrival often coincides with ice-out. On Jack Lake congregations of loons have been observed in the open water of the Narrows before the lake is completely ice-free (A. Johnston pers. comm.). Because the loon s body is long and heavy with legs placed well to the rear, it is extremely clumsy and slow on land. Loons build their nest very close (< 1 m) to the water s edge. This makes their nest very vulnerable to water level fluctuations which may either flood or strand their nest. Increasing water levels by more than six inches can inundate loon nests and decreasing water levels by a foot or more can isolate nests, increasing predation and the difficulty of incubation exchanges. There are several pairs of breeding loons each year on Jack Lake. Members of the JLA have participated in the Canada Lakes Loon Survey for many years (Table 2). The lake is not surveyed every day but, rather, observations are conducted on an opportunistic basis. It is evident, however, that the loon nesting period on Jack Lake is somewhat variable (depending on early or late spring) but usually occurs from mid May to mid-late June. Table 2. Loon arrival and nesting observations for Jack Lake, Ontario. Ice-Out First Spring Year Date Observation Nesting Period First Chicks Observed May 24 late June Late June 2005 April April Late May- late June June June July March 31 April 4 Late May - June July April 17 - Late May - June June March 24 May 4-5 Late May - June July April 29 April 21 May 11 June 22 June 30

5 April It should also be noted that concerns have been expressed about the impact of water level fluctuations on loon nesting on Jack Lake in the past. In 1986, loon nests were flooded out and a petition, signed by many Jack Lake residents/shoreline landowners, was sent to the Trent- Severn Waterway of Parks Canada. References and Literature Cited Allan, B Walleye and muskellunge spawning activity in Jack Lake. Fisheries Management Report. Ontario Ministry of Natural Resources. Bancroft, Ontario. 8 p. + appendices. Corbett, B. W The ecology of an introduced population of walleye (Stizostedion vitreum vitreum) in Jack Lake, Ontario. M.Sc. Thesis. Trent University. Peterborough, Ontario. 145 p. Corbett, B. W. and P. M. Powles Spawning and larva drift of sympatric walleyes and white suckers in an Ontario stream. Transactions of the American Fisheries Society 115: Dosser, S A summary of walleye and muskellunge spawning site identification and documentation in the Bancroft District, spring Fisheries Management Report Ontario Ministry of Natural Resources. Bancroft, Ontario. Dosser, S. and J. Brisbane Walleye and muskellunge spawning site identification and documentation, Fisheries Management Report Ontario Ministry of Natural Resources. Bancroft, Ontario.19 p. Jack Lake Association Fisheries Committee A review of fisheries management activities on Jack Lake and proposals for the future. Jack Lake Association. Apsley, Ontario. 27 p. + appendices. Kerr, S. J., B. W. Corbett, N. J. Hutchinson, D. Kinsman, J. H. Leach, D. Puddister, L. Stanfield and N. Ward Walleye habitat: A synthesis of current knowledge with guidelines for conservation. Percid Community Synthesis. Ontario Ministry of Natural Resources. Peterborough, Ontario. Kerr, S. J., A. J. Dextrase, N. P. Lester, C. A. Lewis and H. J. Rietveld Strategies for managing walleye in Ontario. Percid Community Synthesis. Ontario Ministry of Natural Resources. Peterborough, Ontario. 24 p. + appendices. Legault, M., J. Benoît and R. Bérubé Impact of new reservoirs. p In J. M. Gunn, R. J. Steedman and R. A. Ryder [eds.]. Boreal Shield Watersheds Lake Trout Ecosystems in a Changing Environment. Lewis Publishers. Boca Raton, Florida.

6 Leira, M. and M. Cantonati Effects of water level fluctuations on lakes: An annotated bibliography. p In K. M. Wantzen, K. P. Rothhaupt, M. Mörtl, M. Cantonati, L. Toth and P. Fischer [eds.]. Ecological Effects of Water Level Fluctuations in Lakes. Reprinted from Hydrobiologia p. Olver, C. H., R. L. DesJardine, C. I. Goddard, M. J. Powell, H. J. Rietveld and P. D. Waring Lake trout in Ontario: Management strategies. Lake Trout Synthesis. Ontario Ministry of Natural Resources. Toronto, Ontario8. 86 p. + appendices. Plunkett, J., S. McAlpine, D. Olmstead and A. Yanke lake trout spawning survey on Jack Lake. Northern Outdoor Studies. North Hastings Secondary School. Bancroft, Ontario. 18 p. + appendices. Raabe, J. K. and M. A. Bozek Quantity, structure and habitat selection of natural spawning reefs by walleyes in a north temperate lake: A multiscale analysis. Transactions of the American Fisheries Society 141:

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