PARENT SESSION
Contributed Oral Session 38: Aquatic Faunal Assemblage Responses to Stressors
Tuesday, August 9, 8:00 AM - 11:30 AM, Meeting Room 513 C, Level 5, Palais des congrès de Montréal
Are northern fish populations going to be in hot water due to climate change?
Sharma, Sapna*,1, Jackson, Donald 1, 1 Department of Zoology, Toronto, Ontario, Canada
ABSTRACT- Predictive increases in water temperature due to climate change will have large implications for aquatic ecosystems, such as on thermal habitat and potential range expansion of fish species. Warmwater fish species, such as smallmouth bass, Micropterus dolomieu, may have access to additional favourable thermal habitat under increased surface water temperatures, thereby pushing the northern limit of the distribution of the species further north in Canada and potentially negatively impacting lake trout and cyprinid communities. We tested surface water temperature models from the literature on lakes of different sizes across Canada. Most models focused on small, region-specific lakes and were not reliable predictors of surface water temperatures of lakes across Canada. Models that included an atmospheric driver, i.e. air temperature, and a description of lake morphometry were better at predicting surface water temperatures. However even the best model incurred a large degree of deviation, ranging from −1.65 to 4.65 °C between lakes in different areas. This deviation is sufficiently large to produce substantial error in predicting northern limits of smallmouth bass distributions. Therefore, a nation-wide surface water temperature model that included a description of air temperature and lake morphometry was created for lakes of different sizes in Canada. Lakes with summer surface water temperatures at least between 16.5 and 18 °C were identified and considered to have suitable thermal habitat for smallmouth bass populations. Under a climate change scenario, we were able to identify lakes that will contain suitable thermal habitat and therefore are vulnerable to invasion by smallmouth bass.
Key words: surface water temperatures, smallmouth bass, Micropterus dolomieu, modelling, climate change