Premium
Size‐Dependent Retention of Pelagic‐Oriented Kokanee in Multimesh Gill Nets
Author(s) -
Hansen Adam G.
Publication year - 2019
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 - 10.1002/nafm.10324
Subject(s) - pelagic zone , oncorhynchus , fish <actinopterygii> , benthic zone , fishery , congruence (geometry) , environmental science , statistics , mathematics , biology , geometry
Abstract Recent studies evaluating the size selectivity of standard, horizontal, benthic gill nets for some common sport fish have demonstrated congruence across regions and gear configurations. Studies evaluating retention in gill nets designed to sample pelagic‐oriented fish (e.g., vertical and curtain nets) are rare, which has limited corresponding assessments of generality. This study estimated the retention of kokanee Oncorhynchus nerka (lacustrine Sockeye Salmon) in multimesh vertical gill nets using catch data compiled over three decades from a large montane reservoir in Colorado. The corresponding best‐fit retention model was compared with that developed for kokanee in Idaho using multimesh curtain nets. There was strong congruence (Pearson's r = 0.98) between the total retention values (integrated over all mesh sizes) estimated by the two models for kokanee 50–430 mm total length, and the values followed a 1:1 relationship. This result indicated that the retention of fish in pelagic gill nets may also be largely conserved across regions and gear configurations. Thus, the retention models for kokanee compared in this study should be flexible and broadly applicable. These properties enable practitioners to easily adjust length‐frequency distributions for bias arising from size‐dependent retention when minimally biased estimates of size structure are needed for addressing management or research questions.