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Emergence Trap and Holding Bottle for the Capture of Salmonid Fry in Streams
Author(s) -
Fraley J. J.,
Gaub M. A.,
Cavigli J. R.
Publication year - 1986
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(1986)6<119:etahbf>2.0.co;2
Subject(s) - netting , trap (plumbing) , bottle , streams , fishery , environmental science , oncorhynchus , fish <actinopterygii> , zoology , hydrology (agriculture) , biology , geography , archaeology , geology , geotechnical engineering , environmental engineering , computer science , computer network , political science , law
A 0.12‐m 2 fry emergence trap was constructed of rigid steel strip, plumber's tape, and nylon netting. A holding bottle was fashioned from a polyethylene screw cap bottle and plastic funnel. The trap was inexpensive, durable, and effective in a wide range of current velocities. The method proved effective in estimating egg‐to‐fry survival rates for kokanee (Oncorhynchus nerka) in various sediment mixtures. Egg‐to‐fry survival varied from 0 to 52%, and was negatively correlated to percent fines (r = 0.91; P < 0.01). The emergence period indicated by the trap catches in McDonald Creek agreed closely with the period indicated by drift‐net sampling. Fry mortality in the holding bottle was almost nil if the trap was checked at least once a week.