Visual Observation of Feeding Strategies Used by Brook Trout and Steelhead Trout

TITLE: Visual observation of feeding strategies used by brook trout (Salvelinus fontinalis)  and steelhead trout (Oncorhynchus mykiss)

Authors: Eric Miltz-Miller and Jill B.K. Leonard

Affiliation: Biology Department, Northern Michigan University, 1401 Presque Isle Ave., Marquette, MI

 

Abstract: The primary objective for this project was to examine feeding niche overlap of native brook trout (Salvelinus fontinalis) and non-native steelhead (Oncorhynchus mykiss) in a second order northern Michigan stream using snorkel surveys. Four behaviors were observed:  column feeding, surface feeding, benthic picking, and benthic searching. Daytime observations were made in fall 2011 and spring/summer 2012. It was found that steelhead fed on average 2.1 times per individual per period, whereas brook trout fed 1.5 times per individual per period. Both species showed a preference towards column feeding (brook trout 80% and steelhead 71% of events). Feeding behaviors did not vary with the presence or absence of the other species. Our data did not suggest a shift in brook trout feeding behaviors due to the presence of steelhead; however, they do suggest that steelhead are more active which may lead to competition for food when these two species are found together.