Fishing pressure and environmental variability are two of the most impactful drivers of fish populations worldwide. It is critical to effective management to understand the intersection between the two and how each may affect fish population dynamics, especially for exploited nearshore species like rockfishes (Sebastes spp.). This is especially true as models indicate that global climate change will dramatically increase the frequency and severity of large-scale oceanographic perturbations. We were interested in whether we could detect changes in relative abundance of nearshore rockfishes relative to large-scale oceanographic events using a broad-scale index like the Multivariate Ocean Climate Indicator (MOCI), if detectable changes were different based on the life-stage of the fishes, and whether fishing pressure had an impact on the relationship between environmental variability and fish abundance. To investigate this, we calculated cross correlations between catch per unit effort (CPUE) of Blue Rockfish (Sebastes mystinus) and the MOCI. We used data collected by the California Collaborative Fisheries Research Program (CCFRP) inside of marine protected areas (MPAs) and in paired reference sites to account for fishing effort. We also incorporated data collected before, during, and after the North Pacific Marine Heatwave (NPMHW) into cross correlation analyses. Based on these cross correlations, our findings suggest that oceanographic variability impact juvenile S. mystinus population dynamics with a two-year time lag. Our findings also suggest that fishing pressure impacts adult S. mystinus population dynamics more strongly than juveniles, but that temporal shifts in regional oceanographic conditions appear to alter this relationship. These findings may help to inform groundfish management along the West Coast of the United States and has broader implication for predicting species responses to the combined effects of fishing pressure and oceanographic variability.
In addition to collecting necessary data on the status of fisheries populations, collaborative fisheries research programs engage stakeholders in data collection efforts, often with the benefit of increasing transparency about the status and management of natural resources. These programs are particularly important in marine systems, where management of recreational and commercial fisheries have historically been contentious. One such program is the CCFRP, which was designed in 2006 with two main goals: (1) to evaluate the efficacy of California’s newly implemented network of MPAs while providing information for stock assessments, and (2) to engage anglers in all aspects of the research, including study design, data collection, analysis, and dissemination of scientifically robust data. CCFRP began on the Central Coast of California and expanded in 2017 to include six partner institutions spanning the entire state. To date, over 2,000 volunteer anglers have participated in the program, with many anglers volunteering for multiple years. A previous study that surveyed CCFRP anglers from the Central Coast demonstrated the importance of long-term participation in changing angler opinions of MPAs. Here, we extend that research four years after the expansion of CCFRP by surveying the statewide pool of volunteer anglers to assess the degree that participation in CCFRP has influenced their perceptions of MPAs, fisheries management, and conservation. We received 259 completed surveys, equating to an 18.7% response rate. Participation in CCFRP resulted in a significant, positive impact on the attitudes of anglers across all regions towards MPAs in California. Anglers that participated in six or more CCFRP fishing trips had a more positive perception of MPAs than those that participated in fewer trips. Volunteer anglers across all regions perceived that they caught larger fishes, a higher abundance of fishes, and a greater diversity of species inside MPAs, consistent with the ecological findings of the program. These results highlight the benefits of involving community members in collaborative scientific research. Collaboration between researchers and the broader community increases transparency and trust between stakeholders, results in greater understanding of natural resources, and ultimately produces better management outcomes.
| Identifer | oai:union.ndltd.org:CALPOLY/oai:digitalcommons.calpoly.edu:theses-4251 |
| Date | 01 June 2023 |
| Creators | Johnston, Erin M |
| Publisher | DigitalCommons@CalPoly |
| Source Sets | California Polytechnic State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Master's Theses |
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