An investigation of the movement of predatory fishes in South Fishtail Bay of Douglas Lake.

Abstract

Factors such as predation, proximity to cover and amount of daylight (lightness) may affect the behavior of and interactions between organisms within lake ecosystems. Predatory birds, predatory fish and small fish may have interactions between them that are correlated to other factors. We characterized the presence and possible movement patterns of fish within the littoral zone of South Fishtail Bay of Douglas Lake, Cheboygan Co., Michigan using a trap net and minnow traps. Proximity to cover was different at each site and we compared catch rates during light and dark hours in order to address our experiment's objectives. Our results indicated that most species of predatory fish moved randomly within the bay. Rock bass and yellow perch, however, moved non-randomly with respect to lightness. Largemouth bass and rock bass moved differently at sites when we compared proximity to cover. We concluded that a relationship between small fish and predatory fish exists and predatory birds were affecting this relationship.