Premium
Substrate Conditions and Abundance of Lake Trout Eggs in a Traditional Spawning Area in Southeastern Lake Michigan
Author(s) -
Dorr John A.,
O'Connor Daniel V.,
Foster Neal R.,
Jude David J.
Publication year - 1981
Publication title -
north american journal of fisheries management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 72
eISSN - 1548-8675
pISSN - 0275-5947
DOI - 10.1577/1548-8659(1981)1<165:scaaol>2.0.co;2
Subject(s) - trout , fishery , abundance (ecology) , substrate (aquarium) , fish <actinopterygii> , environmental science , ecology , geography , biology
Spawning by planted lake trout (Salvelinus namaycush) was documented by sampling with a diver‐assisted pump in a traditional spawning area in southeastern Lake Michigan near Saugatuck, Michigan in mid‐November in 1978 and 1979. Bottom depths at the 11 locations sampled ranged from 3 to 12 m and substrate size from boulders to sand. Periphyton (Cladophora and associated biota) was several millimeters thick at most stations but sparse at the shallowest. The most eggs recovered from a single sample occurred at the shallowest depth (3 m). In both years, some of the small numbers of eggs collected (9 in 1978, 14 in 1979) were alive and fertilized. Laboratory incubation of viable eggs resulted in successful hatching of larvae. When compared with egg densities measured at spawning sites used by self‐sustaining populations of lake trout in other lakes, densities in the study area (0‐13/m 2) appeared to be critically low. Insufficient numbers of eggs, combined with harsh incubation conditions (turbulence, ice scour, sedimentation), were implicated as prime causes for lake trout reproductive failure in the study area, although other factors, such as inappropriate spawning behavior (selection of suboptimal spawning location, depth, or substrate) also may have reduced survival of eggs and larvae.