In:
ICES Journal of Marine Science, Oxford University Press (OUP), Vol. 62, No. 8 ( 2005-01-01), p. 1543-1555
Abstract:
We propose a random effects model for disentangling population abundance and capture efficiency effects on bottom-trawl catches. The spatial distribution of individual fish is assumed random leading to a Poisson distribution for the number of individuals in the trawl path (no schooling). Capture efficiency, i.e. the proportion of individuals in the trawl path being retained by the gear, is modelled as a random variable. We propose model extensions that include the effects of body size on haul efficiency. We applied the models to several species from the Celtic Sea groundfish community based on small-scale repetitive hauls. The resulting abundance estimates allowed us to study population abundance ratios; the estimated capture efficiencies were comparable between species and showed that generally gear efficiency increases for larger species with the exception of haddock (Melanogrammus aeglefinus), which had low estimated gear efficiency despite its large body size. Model identifiability was studied using simulations and an independent trawl data set from the same area.
Type of Medium:
Online Resource
ISSN:
1095-9289
,
1054-3139
DOI:
10.1016/j.icesjms.2005.05.010
Language:
English
Publisher:
Oxford University Press (OUP)
Publication Date:
2005
detail.hit.zdb_id:
2463178-4
detail.hit.zdb_id:
1468003-8
detail.hit.zdb_id:
29056-7
SSG:
12
SSG:
21,3
