Growth, mortality, and recruitment signals in age-0 gadids settling in coastal Gulf of Alaska

Details

• Journal Title:
  ICES Journal of Marine Science
• Personal Author:
  Laurel, Benjamin J. ; Knoth, Brian A. ; Ryer, Clifford H.
• NOAA Program & Office:
  NMFS (National Marine Fisheries Service) ; AFSC (Alaska Fisheries Science Center)
• Description:
  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 few age-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.
• Keywords:
  Aquatic Science Ecology Ecology, Evolution, Behavior And Systematics Oceanography Ecology, Evolution, Behavior And Systematics Ecology, Evolution, Behavior And Systematics
• Source:
  ICES Journal of Marine Science, 73(9), 2227-2237
• DOI:
  https://doi.org/10.1093/icesjms/fsw039
• ISSN:
  1095-9289 ; 1054-3139
• Format:
  PDF
• Publisher:
  Oxford University Press (OUP)
• Document Type:
  Journal Article
• License:
  https://creativecommons.org/publicdomain/zero/1.0/
• Rights Information:
  CC0 Public Domain
• Rights Statement:
  This work is written by (a) US Government employee(s) and is in the public domain in the US.
• Compliance:
  Library
• Main Document Checksum:
  urn:sha256:89339f1f53526f97b33b9ce15407385fa3e471795d9c0fcd28300d31dc4cc40b
• Download URL:
  https://repository.library.noaa.gov/view/noaa/53773/noaa_53773_DS1.pdf
• File Type:
  [PDF - 675.66 KB ]