MEPS 288:263-271 (2005) - doi:10.3354/meps288263
The influence of climate on the fishery recruitment of a temperate, seagrass-associated fish, the King George whiting Sillaginodes punctata
Gregory P. Jenkins*
ABSTRACT: The King George whiting fishery in Victoria, Australia, is based on sub-adult fish of 3 to 5 yr old in bays and inlets. Previously, Zonal Westerly Winds (ZWW) and the El Niño southern oscillation index (ENSO) cycle have been found to influence the larval stages and subsequent catches of some fishery species in southeastern Australia. Offshore spawning and long larval life, together with a fishery based on a few year classes of sub-adult fish, led to the hypothesis that the fishery would be strongly influenced by climatic conditions in the larval stage. A significant positive correlation was found between the strength of ZWW in the region and the catch 3 to 5 yr later. These conditions may have influenced larval transport rates, or alternatively may have led to increased plankton productivity and therefore larval food supply. The ENSO cycle, however, was found to have a positive influence on catch at 0 lag. This positive correlation suggested that La Niña conditions may have led to increased catchability of King George whiting. Post-larval abundances at a seagrass site in Port Phillip Bay were strongly correlated with ZWW, confirming that the effect of these winds occurred in the larval to post-larval stages. Overall, results suggest that climatic conditions exert a strong influence on the larval to post-larval stages that subsequently affect the catch in the fishery.
KEY WORDS: Climate · Zonal Westerly Winds · ENSO cycle · King George whiting · Catch trend · Southeast Australia · Sillaginodes punctata
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