Graduation Date

Spring 2022

Document Type

Thesis

Program

Master of Science degree with a major in Natural Resources, option Fisheries

Committee Chair Name

Dr. Andre Buchheister

Committee Chair Affiliation

HSU Faculty or Staff

Second Committee Member Name

Dr. Timothy Mulligan

Second Committee Member Affiliation

HSU Faculty or Staff

Third Committee Member Name

Dr. Joe Tyburczy

Third Committee Member Affiliation

HSU Faculty or Staff

Fourth Committee Member Name

Dr. Jose Marin Jarrin

Fourth Committee Member Affiliation

HSU Faculty or Staff

Subject Categories

Fisheries

Abstract

Marine protected areas (MPAs) were created with the purpose of helping conserve and restore diminished populations of marine organisms. Measuring the effectiveness of MPAs requires long-term monitoring, investigating the abundance and size distributions of the species that utilize the conservation areas, and comparing the results to neighboring reference sites that are not currently protected. In this study, observations from long-term MPA monitoring in northern California (2010-2019) were modeled with substrate, oceanographic, spatial, temporal, and body size variables to describe the variability in abundance and size of three fish groups: Black rockfish (Sebastes melanops), the Blue rockfish group (comprised of Blue rockfish (Sebastes mystinus) and Deacon rockfish (Sebastes diaconus)), and Lingcod (Ophiodon elongatus). Models were also used to explain the differences in the abundance and size associated with protection status (MPA vs. reference). The data consisted of two MPAs and their paired reference sites (accessed from the ports of Eureka and Fort Bragg, CA), and another set of two auxiliary reference sites north of Trinidad, CA that were not paired with an MPA. Lagged oceanographic covariates had strong relationships with relative abundance of Black rockfish and illustrated the importance of upwelling as a long-lasting driver of adult relative abundance. Lagged oceanographic effects could be products of the long-term effects that upwelling has on recruitment. Substrate covariates and distance to port played an important role in describing the variability in relative abundance and length of the species, while substantiating previous studies. Weak, but detectable, effects of protection status on abundances of lingcod and lengths of all species were also found. The presence of detectable signals indicates that the MPAs within this study are beginning to positively influence abundances and lengths of the fish that reside within them, further supporting their utility and functionality as tools of conservation that can be used by fisheries managers. This study adds general information and critical insight into the population dynamics, environmental drivers, and management effectiveness of the species studied, along the California North Coast.

Citation Style

APA

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