Relationships Among Somatic Growth, Climate, And Fisheries Production In An Overexploited Marine Fish From The Gulf Of California, Mexico

Relationships among somatic growth, climate, and fisheries production are poorly understood for coastal fishes in the Gulf of California (GoC), Mexico, but may serve as an adaptive management tool to set precautionary harvest limits for overfished, data-limited stocks. We explored linkages among the Multivariate ENSO Index (MEI), regional sea surface temperatures (SST), otolith growth chronologies of juveniles and adults, and annual landings in the Gulf corvina (Cynoscion othonopterus), an overexploited marine fish that supports the most important coastal finfish fishery in the northern GoC. Both MEI and SST were positively correlated with corvina landings five years later (peak age at capture), indicating that climate conditions at birth were a reliable predictor of future fisheries production. Juvenile growth rate covaried with both MEI and SST, confirming the influence of climate during early life history. There was no significant covariance from year to year in adult growth rate, but there was a significant cohort effect that positively correlated with MEI and SST, suggesting that climate conditions early in life exert lasting impacts that persist through adulthood. Differences in climate-growth relationships between juveniles versus adults were attributed to differences in the geographic distributions of the two life stages. Overall, we conclude that climate variability influences the future harvestable biomass of the corvina fishery via impacts on juvenile growth, and thus survivorship. Systematic monitoring of the corvina population, its fishery, and the biophysical components of the GoC environment must continue to improve our understanding of these climate-driven processes and the management of the fishery.