Habitat use of Lake Trout follows lake thermal cycles in Eastern Lake Ontario

Session: Restoration and Management of Great Lakes Fishes (1)

Silviya Ivanova, University of Windsor, [email protected]
Timothy Johnson, Ontario MNRF, Glenora Fisheries Station, [email protected]
Brent Metcalfe, ON Ministry of Natural Resources, [email protected]
Aaron Fisk, University of Windsor, [email protected]

Abstract

Animal movements are influenced by the environment they inhabit, thus, thermal cycles in temperate lakes are important for habitat selection. Lake trout (LT) is a demersal native top predator in Lake Ontario currently under rehabilitation in both Canada and the US. This cold, deep-water species is known to migrate to shallower depths in the fall to spawn in eastern Lake Ontario, yet their spatial and temporal habitat preferences have not been examined in detail until now. Here, we used acoustic telemetry to examine LT residency and home ranges as influenced by the lake’s thermal cycles. Lake trout show a restricted deep-water residency during stratification, and variable, broad distribution during periods of warming, cooling and constant cold water temperatures. Home ranges also were variable and confirmed the residency results - located south of Galloo and Main Duck Islands during stratification and distributed north and west in the shallower Kingston basin during the remainder of the year. A single individual travelled from the east to the west end of Lake Ontario. Our results imply highly individualistic movements for individuals. Quantifying the habitat use of LT is important for understanding their ecology in changing environmental condtions, and thus, for informing rehabilitation efforts.