Inexpensive Method for Quantitative Assessment of Lake Trout Egg Deposition
January 1, 1989 - William H. Horns; J. Ellen Marsden; Charles C. Krueger
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EmailJournal or Book Title: North America Journal of Fisheries Management
Volume/Issue: 9
Page Number(s): 280-286
Year Published: 1989
Little evidence exists for extensive natural reproduction by lake trout Salvelinus namaycush stocked in the Great Lakes, except in Lake Superior. An obstacle to the systematic study of the fate of eggs produced by stocked fish has been the inability to inexpensively detect egg deposition and to measure egg deposition rates. We have developed a low-cost (US$7.00 per egg net), reusable egg-collection device (egg net) that can be set and recovered from shipboard. Egg nets placed on spawning substrate prior to spawning collect eggs passively and protect the eggs until their retrieval. The nets were tested on a shallow reef in Lake Ontario and on a deep reef in Lake Michigan. In Lake Ontario, 24 nets captured 261 eggs (336 eggs/m2) from October 13 to November 13, 1987, and 23 nets captured 1,830 eggs (2,455 eggs/m2) from November 13 to November 24, 1987. Over 50% of the eggs recovered were alive. Storms overturned some nets at the shallow-water site. No eggs were recovered in Lake Michigan, but inspection by a remotely operated video camera confirmed that 90% of the nets were upright 19 d after placement. With appropriate modifications for eggs of other sizes, the egg nets may also be useful for assessment of spawning by other species offish.
Type of Publication: Journal Article
