Bottom-up and top-down control of small pelagic forage fish: factors affecting age-0 herring in the Strait of Georgia, British Columbia

Details

• Journal Title:
  Marine Ecology Progress Series
• Personal Author:
  Boldt, JL ; Thompson, M ; Rooper, CN ; Hay, DE ; Schweigert, JF ; Quinn TJ, II ; Cleary, JS ; Neville, CM
• NOAA Program & Office:
  NMFS (National Marine Fisheries Service) ; AFSC (Alaska Fisheries Science Center)
• Description:
  Small pelagic fish are key planktivores and prey in marine ecosystems, and their population abundances undergo strong temporal and spatial variability. Top-down (predator controlled) and bottom-up (prey-driven) processes during early life history are important for determining forage fish survival and recruitment. We examined biological and environmental factors hypothesized to influence age-0 Pacific herring Clupea pallasi in the Strait of Georgia (SOG), British Columbia, Canada. Primarily bottom-up processes affected interannual variability in age-0 herring abundance and condition, with some evidence of top-down effects on condition. Age-0 herring abundance increased with increasing adult spawning biomass and peaked when most adults spawned about 20 d prior to the peak spring primary production bloom. This timeline would temporally align first-feeding herring larvae with their prey, such as small copepods. Age-0 herring abundance also increased with increasing juvenile salmon abundance, indicating that conditions favourable for herring were also favourable for their predators and competitors. Age-0 herring condition decreased with increasing spawning biomass, increased when most adults spawned closer to the peak spring bloom, increased with increasing temperatures above 8.2°C, and increased then stabilized with increasing prey zooplankton density. Age-0 herring condition had a dome-shaped relationship with predator abundance, indicating that high predator abundances negatively affected fish condition. Study results suggest that density-dependent processes, such as intraspecific competition, may be important in the SOG. A positive correlation between age-0 herring abundance and subsequent age-3 recruit abundance may provide a leading indicator of low recruitment years.
• Source:
  Marine Ecology Progress Series, 617-618, 53-66
• DOI:
  https://doi.org/10.3354/meps12485
• ISSN:
  0171-8630 ; 1616-1599
• Format:
  PDF
• Publisher:
  Inter-Research Science Center
• Document Type:
  Journal Article
• License:
  https://creativecommons.org/licenses/by/4.0/
• Rights Information:
  CC BY
• Compliance:
  Library
• Download URL:
  https://repository.library.noaa.gov/view/noaa/65336/noaa_65336_DS1.pdf
• File Type:
  [PDF - 1.37 MB]
• Collection(s):
  National Marine Fisheries Service (NMFS)
• Main Document Checksum:
  urn:sha-512:1569fda306972145b0764309cff0ba6f9421bac7049d4c1bb6b11072390439a4e618adffbf10228abc757832b903cdeff1fed7cf5a411a78649dbc1e3626be77