Understanding the processes that affect fish recruitment is a fundamental issue in fisheries science. The goal of this project is to determine if larval fish condition (based on maternal investment and growth) during the larval stage impacts rockfish recruitment. We will measure these traits, along with larval morphology (e.g. length vs. girth), using rockfish larvae that were collected by the California Cooperative Oceanic Fisheries Investigative program (CalCOFI) between 1998 and 2017 and previously identified through genetic barcoding of individual larvae. Otolith-measures of larval conditions will be evaluated by extracting otoliths and measuring otolith core size (an index of maternal investment) and outer otolith band widths (an index of how fast a larva is growing in the final days of life) from 8 rockfish species. We will then determine whether measures of larval condition correlate with both environmental conditions (e.g. temperature, salinity, and chlorophyll) and recruitment indices derived either from stock assessments or densities of young of the year rockfishes in southern California that were collected approximately 3 months after CalCOFI sampling. We will test the hypothesis that recruitment is higher when maternal investment is high and/or larvae are growing at a rapid rate, and that larvae are more robust when water temperature is cool and chlorophyll high.
Thompson AR, Chen DC, Guo LW, Hyde JR and Watson W. 2017. Larval abundances of rockfishes that were historically targeted by fishing increased in a large marine protected area over 16 years. Royal Society Open Science 4:170639.
Thompson AR, Hyde JR, Watson W, Chen DC, Guo LW 2016. Rockfish assemblage structure and spawning locations in Southern California identified through larval sampling. Marine Ecology Progress Series 547:177-192.
Thompson AR, Auth TD, Brodeur RD, Bowlin NM, and Watson W. 2014. Dynamics of larval fish assemblages in the California Current System: comparative study between Oregon and southern California. Marine Ecology Progress Series 506: 193-212.
Fishery science; larval fish; Recruitment; Maternal investment; CalCOFI; Marine ecology