Reconstructing the population dynamics of southern California Paralabrax species in the face of a changing ocean

R/OPCSFAQ-9
Start/End: December, 2018 to December, 2021

The saltwater basses (Paralabrax species) are an important recreational fishery in California. This state-managed fishery is comprised of three species that are managed as a single unit: barred sand bass, kelp bass, and spotted sand bass. While no biomass estimates exist for the species, reduced catches over the past decades suggest that at least one of the populations is depressed, most likely because of a combination of environmental factors and pressures from fishing. However, understanding of the population is limited by the lack of long-term abundance data for each species.

This project aims to reconstruct 67 years of data from the California Cooperative Oceanic Fisheries Investigations on Paralabrax species ichthyoplankton (fish eggs and larvae). The researchers will use molecular and morphological identification to evaluate trends in the population dynamics of each species relative to oceanographic conditions.

The proposed research will result in several products, including a long-term fishery-independent time series of Paralabrax larval abundance, a species-specific predictive spatial distribution model of larval abundance, and additional diagnostic tools for species identification of formalin-preserved Paralabrax larvae. These additional tools will help improve monitoring and assessment and form a framework that to support incorporation of changing ocean conditions into management. Overall, this project aims to provide the information necessary to support the state’s efforts to sustainably manage the important bass fisheries under the MLMA Master Plan, and in the face of a changing ocean.

  • University of California, San Diego, Scripps Institution of Oceanography