Publikationsdatum:
2018-03-06
Beschreibung:
Ecosystem structure and function in the eastern Bering Sea are impacted by seasonal, interannual, and spatial variation of the zooplankton community. Zooplankton abundance, community composition and individual responses of key taxa, in spring, summer, and fall were evaluated across ecoregions during three years with high sea-ice, 2008–2010 (cold years). Interannual variations were greatest in spring, but less pronounced compared with intra-annual variations. Intra-annual variations were greatest in the south middle domain in spring and the north middle domain in all seasons. Models using environmental variables were able to explain 69–77% of zooplankton community variation within each season. Among individual taxa, Calanus marshallae/glacialis had delayed stage progression in spring 2009 compared with 2008 and 2010 on the south middle shelf, likely due to late ice retreat and cold temperatures that increased development times. In contrast, stage progression was fastest in summer 2008 likely due to warmer temperatures. Our findings indicate that intra-annual variation of zooplankton community composition, life history stage, and abundance within a cold period may affect the amount of high–lipid zooplankton prey (e.g. Neocalanus and Calanus spp. copepods and euphausiids) available seasonally for forage fish (e.g. age-0 walleye pollock) to grow to a sufficient size (to avoid size-dependent predation) and have sufficient lipid stores (to avoid starvation) to survive the first winter at sea.
Print ISSN:
1054-3139
Digitale ISSN:
1095-9289
Thema:
Biologie
,
Geologie und Paläontologie
,
Physik
