Temporal and spatial distribution of trout on the Main Branch of the Maple River.

Abstract

The purpose of this study was to determine the spatial and temporal distribution of trout (Salmonidae) activity on the Maple River in Cheboygan County, MI. We observed trout surface feeding at sunrise (5-7am), early afternoon (12:45-3pm), and at sunset (8-10pm). Along with out-of-water observations, we also snorkeled to observe trout within their natural environment. Significant evidence was found that showed trout preferred sunrise feeding to either of the other observation periods. We also recorded significant results showing that trout preferred the upstream site (Site #1) over either of the others. Site #1 had abundant woody debris, deep pools, rock-sand mixed substrate, moderate macrophytes, and a slower current than the other sections. In our underwater observations, we saw trout feeding and finding refuge in pools, among woody debris with rocky substrates, but not in areas with high percentages of macrophyte growth. We concluded that pool abundance, large amounts of woody debris and rocky substrate are critical to trout habitat. The combinatin of these factors made Site #1 the most ideal for surface feeding and diurnal activity.