Extension of biomass estimates to pre-assessment periods using density dependent surplus production approach.

ABSTRACT: Biomass reconstructions to pre-assessment periods for commercially important and exploitable fish species are important tools for understanding long-term processes and fluctuation on stock and ecosystem level. For some stocks only fisheries statistics and fishery dependent data are available, for periods before surveys were conducted. The methods for the backward extension of the analytical assessment of biomass for years for which only total catch volumes are available were developed and tested in this paper. Two of the approaches developed apply the concept of the surplus production rate (SPR), which is shown to be stock density dependent if stock dynamics is governed by classical stock-production models. The other approach used a modified form of the Schaefer production model that allow

SUBMITTER: Horbowy J 

PROVIDER: S-EPMC5683571 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature