Premium
Effectiveness of Experimental Escape Mechanisms in Sablefish Traps
Author(s) -
Scarsbrook J. R.,
McFarlane G. A.,
Shaw W.
Publication year - 1988
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 - 10.1577/1548-8675(1988)008<0158:eoeemi>2.3.co;2
Subject(s) - slash (logging) , escapement , environmental science , square (algebra) , cylinder , barrel (horology) , materials science , composite material , biology , fishery , mathematics , ecology , geometry
Experiments comparing the efficiency of escape mechanisms were conducted with conical traps for sablefish Anoplopoma fimbria . A 20‐cm slash in the trap wall, a square 30.5‐cmdiagonal panel, and an 18‐cm‐high triangular panel fastened with a corrodible “time‐release” device (magnesium alloy cylinder) were tested. The effectiveness of the escapement mechanisms in the traps was 56% with the 20‐cm slash, 99% with the square panel, 90% with the triangular panel equipped with the “time‐release” device, and 99% with the triangular panel left in the open position. Cotton butcher's twine is recommended as a binding material for escape panels because, among six bindings tested, butcher's twine disintegrated fastest. Cotton butcher's twine reached a 0‐kg breaking strength in 31 d and disintegrated in 46 d. Estimates of annual sablefish loss in traps lost on the grounds during 1977–1983 ranged from 73 to 1,331 tonnes and annual harvests ranged from 1,085 to 4,409 tonnes.