Ecology and Control of Introduced Yellow Perch in BC Lakes

Yellow perch (Perca flavescens) may threaten native fishes and aquatic ecosystems in British Columbia. Introduced species can rapidly adapt to new environments by exhibiting changes in behavior and life history traits. Although general yellow perch ecology is well documented in other parts of Canada and the United States, we know little about yellow perch diet and their preferred habitat in BC’s interior. Determining if there are differences between native and invasive populations may help to show why they are successful invaders and help to predict future impacts.

Here we studied feeding ecology and movement of introduced yellow perch in seven lakes in BC’s interior. Stomach contents of yellow perch and rainbow trout were analyzed for each season (summer, late summer and fall 2011, winter 2012) to determine if yellow perch are selecting for specific food items and if dietary overlap is occurring with rainbow trout. Food availability was determined through benthic and zooplankton sampling. General movement patterns of yellow perch were recorded in two lakes using 24 hour radio telemetry. Artificial spawning substrates were tested as a possible method to reduce reproductive success by removing egg masses.

Preliminary results from study lakes in BC’s interior show that yellow perch introduced into Pinaus and Bear Lakes are predominantly littoral, moving parallel to the shoreline during the day and becoming stationary during the night. The greatest movement occurred at dawn and dusk periods. Yellow perch diet was dominated by littoral macrobenthos, particularly amphipods and immature diptera (larvae and pupae) in Pinuas Lake. Significant seasonal variation in diet was likely linked to resource availability. In late summer, snails were commonly consumed in addition to amphipods and immature diptera and in fall, mysis shrimp were also a main food source.