Date of Award

Spring 4-20-2021

Document Type

Thesis: Open Access

Degree Name

MS Marine Science

Department

Environmental and Ocean Sciences

Committee Chair

Drew Talley

Abstract

Like ocean systems around the world, species targeted by the San Diego sportfishery are subject to myriad threats from human activity, with several species already showing documented decline. However, long-term fisheries datasets are often lacking, limiting natural resource managers’ ability to appropriately manage these ecologically and economically important species. Therefore, this study used daily reports published in two Southern California newspapers to examine changes in catch composition, effort, and catch per unit effort (CPUE) from 1959-2011 for the San Diego commercial passenger fishing vessel (CPFV) sportfishery. This study then tested the relationship between those patterns and three large scale oceanographic conditions to provide insights into potential drivers of change. During the study period, composition of landings changed from being dominated by relatively few species in the 1960s and 1970s to a richer, and different, composition in the 1990s through 2010s. No species displayed a trend of increasing CPUE, while CPUE for several species (Bonito, Barracuda, and Mackerel) decreased across the study period and changes in large-scale oceanographic conditions alone did not explain the change. Despite the popularity of California Halibut in the sportfishing community, its CPUE appears to have stabilized at low levels, potentially making it an example of a shifting baseline. Meanwhile, Sebastes spp were strongly associated with cold water, suggesting it may be prudent to model expected responses of species within this genus to changing ocean temperatures associated with global climate change. The State of California has and will continue to invest in the management of its coastal marine resources. These actions will be both more effective and more cost-efficient when based on the best available information regarding the populations and habitats it seeks to protect. As this study has shown, analysis of CPFV landings, combined with oceanographic data and information on management and angler preferences, can provide an important tool to help understand what is happening in the populations of popular sportfishing species.

Download

Share

COinS