Andrea N. Odell

Ecosystem dynamics can lead to trade‐offs between reaching harvest targets and protecting vulnerable species across fisheries management decisions. However, in the context of rebuilding overfished populations, considering predator–prey interactions might provide opportunities to minimize or reverse these trade‐offs if overfished prey can recover when predators in shared habitat are harvested. To understand whether and under what conditions such opportunities might arise, we explore the effect of predator harvest on the rebuilding outcomes of a recovering prey that experiences bycatch mortality. We developed an age‐structured model with predation and harvest to evaluate changes in the population dynamics of prey at steady state and in their rebuilding time under increasing harvest of predators. We parameterized our models based on yelloweye rockfish ( Sebastes ruberrimus ), a U.S. West Coast Groundfish stock under a rebuilding plan, and one of their known predators, lingcod ( Ophiodon elongatus ). We found that lingcod harvest reduced the long‐term spawning biomass and increased the rebuilding time of yelloweye rockfish regardless of their prey specialization; these negative effects were due to yelloweye rockfish bycatch in the lingcod fishery. However, the degree to which predator harvest affects prey rebuilding depends on prey specialization, where the steady‐state dynamics of yelloweye rockfish were less affected by lingcod harvest and rebuilding occurred more rapidly when lingcod acted as a specialist compared to a generalist predator. As efforts to leverage ecosystem attributes in fisheries management are applied to recovery strategies, we highlight the role that the nature and strength of biological interactions can play in shaping outcomes of recovery.

Recreational fisheries in remote regions often operate under limited regulation and data availability, presenting challenges for sustainable management. Diego Garcia, located within the Chagos Marine Protected Area, hosts a unique recreational reef fishery embedded within a highly protected environment. We assessed the stock status of five key species— Lutjanus bohar , L. gibbus , L. monostigma , Caranx melampygus , and Variola louti —using the Length‐Based Spawning Potential Ratio (LB‐SPR) approach and length composition data collected through stereo‐video surveys. The average spawning potential ratio (SPR) across all species appears to be operating above 30%, a common threshold below which a stock can be considered overfished. The SPR of L. bohar and L. gibbus remained above 30% across all bootstrap iterations indicating confidence that these species are exploited at a sustainable level. L. monostigma , C. melampygus , and V. louti exhibited greater uncertainty in their estimated SPR, spanning all possible values with at least 50% of bootstrap iterations remaining above 30% SPR; for these species, caution should be applied until additional sampling can improve the resolution of these estimates. These findings suggest that the recreational fishery is operating within sustainable limits, likely due to access restrictions and diffuse fishing pressure across species. However, uncertainty in model outputs for data‐limited species underscores the need for continued biological sampling and catch monitoring.

Objective: Variability in somatic growth of marine fish can affect their reproductive potential and survival and, therefore, the productivity of a population. Understanding how growth might vary among species can improve predictions of population status and responses to environmental change. Our objective was to characterize the variability in growth and body condition of groundfish species along the U.S. West Coast to support their monitoring and assessment. Methods: We used geostatistical models to estimate growth rate and body condition, two interrelated traits associated with somatic growth, across space and time for nine commercially important U.S. West Coast groundfish species. We fit generalized linear mixed models with Gaussian Markov random fields to biological data collected from annual bottom trawl surveys to estimate variability at a 4- × 4-km spatial resolution. Results: Our models uncover spatiotemporal variability in growth rate and body condition in all nine groundfish species with limited trends shared among species with similar traits, suggesting a greater influence from niche partitioning acting on local scales. Such interspecific differences in growth rate and body condition also occurred at regional scales, with some species exhibiting positive responses while others declined. Conclusions: These findings reveal the dynamic nature of somatic growth among groundfish species and provide insight into potential mechanisms of its variability that could be considered within climate-enhanced assessments of population status for marine fish.

Variability in somatic growth of marine fish affects their reproductive potential and survival, and therefore, the productivity of a population. Understanding how growth might vary among species with similar traits can improve predictions of population status and responses to environmental change. We used geostatistical models to characterize spatiotemporal variability in growth rate and body condition, two interrelated traits associated with somatic growth, of nine commercially important U.S. West Coast groundfish species with a range of life-history traits and depth distributions. Our models uncover spatiotemporal variability in growth rate and body condition in all nine groundfish species with limited trends shared among species with similar traits, suggesting a greater influence from niche partitioning acting on local scales. Such interspecific differences in growth rate and body condition responses also occurred at regional scales, with some species exhibiting positive responses while others declined. These findings reveal the dynamic nature of somatic growth among groundfish species and provide insight into potential mechanisms of its variability that could be considered within climate-enhanced assessments of population status for marine fish.