SS1.09 Fisheries Population Linkage Spatial and Temporal Variation in Zooplankton
Date: Wednesday, June 12, 2002
Location: Poster Session - VCC
 
KlineTC, Prince William Sound Science Center, Cordova, USA, tkline@pwssc.gen.ak.us
 
FROM INDIVIDUALS TO POPULATIONS: FISH-COPEPOD LINKAGES THROUGH NATURAL STABLE ISOTOPE ABUNDANCE
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Organic carbon generated in the Gulf of Alaska (GOA) was determined to be isotopically distinctive from that originating in Prince William Sound, Alaska (PWS) based on the bi-model distribution of C-13/C-12 values measured in individual copepods. When the oceanic copepod Neocalanus was actively feeding in surface waters, the majority of individuals from a given hydrographic station, or an aggregate of several stations within an area (either PWS or GOA), had isotopic signatures consistent with one isotopic mode. However, a small number of individuals had isotopic values of the alternate mode, which was similar to those from outside the area, suggesting the result of recent advection. The proportion of the copepod population diapausing (over-wintering resting phase) within deep portions of PWS having the isotopic mode of GOA varied from year to year. Juvenile fishes had C-13/C-12 values that matched the range found in copepods and varied systematically with the copepods in diapause suggesting common external forcing. C-13/C-12 abundance demonstrated that GOA oceanic productivity potentially subsidizes and is therefore important for fish production in adjacent coastal waters such as PWS.