Precision in estimates of density and biomass of Norwegian spring-spawning herring based on acoustic surveys

Autor: Øyvind Tangen, Åge S. Høines, Guðmundur J. Óskarsson, Jan Arge Jacobsen, Erling Kåre Stenevik, Jon Helge Vølstad, Sondre Aanes
Rok vydání: 2015
Předmět:
Zdroj: Marine Biology Research. 11:449-461
ISSN: 1745-1019
1745-1000
Popis: The abundance and biomass of the Norwegian spring-spawning herring (NSSH) stock are assessed annually using a virtual population analysis (VPA) applied to catch-at-age data from the fishery and fishery-independent abundance indices derived from research vessel surveys for calibration (‘tuning’). The most important of these surveys is the International Ecosystem Survey in the Nordic Seas (IESNS) and this is highly influential for the outcome of the assessment. Until now, the abundance indices from the IESNS have been reported without any measure of uncertainty. In this study, the sampling errors associated with the density estimates of NSSH from the IESNS for the years 2009–2012 are estimated using design-based survey sampling theory. The annual survey estimates of number and biomass of herring per square nautical mile (nm2) were relatively precise for all age groups combined, with relative standard error (RSE) ranging from 8% to 15%, while for each individual age group (3–12) the RSE was less than...
Databáze: OpenAIRE
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