Summer Habitat Use by Introduced Smallmouth Bass in an Oligotrophic Adirondack Lake

ABSTRACT

Non-native smallmouth bass became established in 1951 in Little Moose Lake, an oligotrophic Adirondack lake. Salmonids dominated the littoral zone at the time. Snorkel surveys, from late June through early August 1997, were used to determine the distribution and abundance of fish in the littoral zone. Transects were established on four habitat types: sand, wood (submerged trees), rock covered by silt (particles < 2 mm), and clean cobble (particles >64 mm). Non-native smallmouth bass were the most common fish species observed over the transects. Counts of adult smallmouth bass (Micropterus dolomieu) were greater than pumpkinseed (Lepomis gibbosus) and salmonids. Average lengths of bass were different between habitat types indicating size class segregation among the habitats in the littoral zone. Adult bass (>50 mm) were only observed on wood and cobble habitats. Nearly all bass >300 mm were observed on wood habitats. Young-of-year bass (<50 mm) were only observed on sand and silted rock. Only two brook trout (Salvelinus fontinalis) and three rainbow trout (Oncorhynchus mykiss) were observed; however, water temperature (range 21 °C to 24 °C) may have limited their presence. We conclude that non-native smallmouth bass dominate the littoral zone of this Adirondack lake during the summer.