Relative Abundance of Lake Trout and Burbot in the Main Basin of Lake Michigan in the Early 1930s

Autor: Randy L. Eshenroder, James R. Bence, Camille Ward
Rok vydání: 2000
Předmět:
Zdroj: Transactions of the American Fisheries Society. 129:282-295
ISSN: 1548-8659
0002-8487
Popis: We used general linear models to compare and to assess the sources of variation in CPUEs (catches per unit effort) of lake trout Salvelinus namaycush and burbot Lota lota netted in small-mesh gill nets from the main basin of Lake Michigan in the early 1930s, before populations of both species collapsed. Spring, summer, and fall CPUEs were modeled separately. In all seasons combined, CPUEs were over 2.5 times greater for lake trout than for burbot, and lake trout CPUEs were greater than burbot CPUEs in five of six regions of the lake. The hypothesized sources of variability in log e (CPUE) included lake region, depth (either as a linear [depth only] or a quadratic [depth and depth2 included] relationship), number of nights out that the nets fished (also as either a linear or quadratic relationship), and the possibility that the effects of depth could vary among regions. The models predicted 57–68% of the variation in lake trout CPUE and 29–37% of the variation in burbot CPUE (log scales). Lake reg...
Databáze: OpenAIRE
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