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Growth, mortality, and recruitment signals in age-0 gadids settling in coastal Gulf of Alaska.
- Source :
-
ICES Journal of Marine Science / Journal du Conseil . Sep2016, Vol. 73 Issue 9, p2227-2237. 11p. - Publication Year :
- 2016
-
Abstract
- Age-0 juveniles may be the earliest, reliable indicators of recruitment into commercial marine fisheries, but independent fisheries assessments are usually conducted on older life stages in adult habitats. We used an 8 year juvenile gadid survey along the coast of Kodiak, Alaska to examine annual abundance, growth and mortality in age-0 Pacific cod (Gadus macrocephalus), with comparisons to saffron cod (Eleginus gracilis) and walleye pollock (Gadus chalcogrammus) where possible. Annual abundance of age-0 fish was positively correlated among all three species, suggesting Pacific gadids respond similarly to processes controlling pre-settlement survival and/or delivery to coastal nurseries. In Pacific cod, June temperature was positively correlated with size-at-settlement but post-settlement growth was density- rather than temperature-dependent. Age-0 abundance indices for Pacific and saffron cod predicted the number of age-1 fish the following year (i.e. positive "recruitment signals"), but only in the larger nursery (Anton Larsen Bay) where age-1 gadids were more likely to remain resident after their first year. Recruitment signals for Pacific cod improved with later estimates of age-0 abundance, likely because of high mortality following settlement in July. In contrast, very fewage-0 and age-1 walleye pollock were caught across the entire time-series of the survey. Collectively, these data suggest that nearshore surveys may be a tractable means of examining early life history processes and assessing year-class strength in juvenile Pacific and saffron cod, but have relatively low value in understanding the population dynamics of walleye pollock. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 10543139
- Volume :
- 73
- Issue :
- 9
- Database :
- Academic Search Index
- Journal :
- ICES Journal of Marine Science / Journal du Conseil
- Publication Type :
- Academic Journal
- Accession number :
- 118531831
- Full Text :
- https://doi.org/10.1093/icesjms/fsw039