Philina A. English

Measures of an organism's weight at a given length are often considered reliable indicators of energy reserves or ‘condition’, which can be related to fecundity and risk of mortality. Understanding the impact of environmental change on fish condition may therefore inform sustainable management of human activities in marine ecosystems. We investigated how changes in Canadian Pacific waters may be influencing the average condition of 35 commercially, culturally, and/or ecologically important demersal fish species. Because the condition of mature male and female, and immature individuals differs in its implications for population dynamics, ecological drivers, and measurement variability, we analysed these three maturity groups separately. We estimated density distributions, calculated Le Cren's relative body condition deviations, modelled spatiotemporal change in these deviations, and generated density‐weighted annual indices of body condition. We used Bayesian Dynamic Factor Analysis to identify common trends across species and tested for correlations with environmental variables. For most species, warmer sea surface temperature and lagged North Pacific Gyre Oscillation appeared neutrally or positively correlated with condition. Only the immature condition was also strongly correlated with primary production, but this effect was equally likely to be negative (e.g., Pacific Spiny Dogfish, Lingcod, and Sablefish) as positive (e.g., Quillback Rockfish, Southern Rock Sole, and Spotted Ratfish). Our approach propagates uncertainty from condition estimation through to environmental correlations to provide both ecosystem‐level and species‐specific inference. Robust estimates of relationships between condition and environmental variables can inform ecosystem approaches to fisheries management, including short‐term forecasts of weight‐at‐age or recruitment.

Quantifying broad‐scale population trends and distribution change is critical for effective management and conservation of marine species, particularly under climate change. However, fragmented regional survey data often hinder such efforts for transboundary populations. A prime example is Pacific Spiny Dogfish ( Squalus suckleyi , Squalidae), a small shark with a remarkably slow life history and wide‐ranging distribution. Dogfish are now caught incidentally but were heavily fished along the Pacific US–Canada coast ≈80 years ago. Reports on local population trends have conflicted along the coast, suggesting that movement between regions may be responsible. We fit spatiotemporal models integrating data from 10 surveys to synthesise trends in biomass, abundance, distribution and thermal niche for dogfish across their entire eastern Pacific Ocean range. Prior to 2003, Alaskan biomass increased through the 1990s whereas California to British Columbia indices were variable and imprecise. However, during 2003–2023, we found a coastwide 51% (95% CI: 38%–61%) decline in dogfish biomass with mature females and immature dogfish showing the largest proportional declines. Regionally, declines were steepest for the US West Coast (71%–85%) and Canada (58%–82%), while Alaska showed less severe declines (13%–54%). Off the US West Coast, dogfish shifted into deeper waters as temperatures in their habitat increased, but these patterns do not explain the coastwide declines. Our results suggest population declines are primarily driven by reduced abundance rather than between‐region movement, indicating elevated coastwide conservation concern and helping focus investigations of causal mechanisms.

Fisheries management faces challenges due to political, spatial, and ecological complexities, which are further exacerbated by variation or shifts in species distributions. Effective management depends on the ability to integrate fisheries data across political and geographic boundaries. However, such efforts may be hindered by inconsistent data formats, limited data sharing, methodological differences in sampling, and regional governance differences. To address these issues, we introduce the surveyjoin R package, which combines and provides public access to bottom trawl survey data collected in the Northeast Pacific Ocean by NOAA Fisheries and Fisheries and Oceans Canada. This initial database integrates over 3.3 million observations from 14 bottom trawl surveys spanning Alaska, British Columbia, Washington, Oregon, and California from the 1980s to present. This database standardizes variables such as catch-per-unit-effort (CPUE), haul data, and in-situ measurements of bottom temperature. We demonstrate the utility of this database through three case studies. Our first case study develops a coastwide biomass index for Pacific hake (Merluccius productus) using geostatistical index standardization, comparing results to independent acoustic survey estimates. The second case study examines spatial patterns in groundfish community structure, highlighting breakpoints between assemblages in their mixture of life histories and trophic compositions. Our third example applies spatially varying coefficient models to assess sablefish (Anoplopoma fimbria) biomass trends, identifying regional variability in increases in occurrence and biomass. Together, these case studies demonstrate how the surveyjoin R package and database may improve species and ecosystem assessments by providing insights into population trends across geopolitical boundaries. This database and package represent an important step toward offering a scalable framework that can be extended to include additional data types, surveys, and species. By fostering collaboration, transparency, and data-driven decision making, surveyjoin supports international efforts to sustainably manage shared marine resources under dynamic environmental conditions.

Fisheries management faces challenges due to political, spatial, and ecological complexities, which are further exacerbated by variation or shifts in species distributions. Effective management depends on the ability to integrate fisheries data across political and geographic boundaries. However, such efforts may be hindered by inconsistent data formats, limited data sharing, methodological differences in sampling, and regional governance differences. To address these issues, we introduce the surveyjoin R package, which combines and provides public access to bottom trawl survey data collected by NOAA Fisheries and Fisheries and Oceans Canada in the Northeast Pacific Ocean. This initial database integrates over 3.3 million observations from 14 bottom trawl surveys spanning Alaska, British Columbia, Washington, Oregon, and California from the 1980s to present. This effort standardizes variables such as catch-per-unit-effort (CPUE), haul data, and in-situ measurements of bottom temperature. We demonstrate the utility of this database through three case studies. Our first case study develops a coastwide biomass index for Pacific hake ( Merluccius productus ) using geostatistical index standardization, comparing results to independent acoustic survey estimates. The second case study examines changes in the spatial distribution of groundfish species across marine heatwave and non-heatwave years, highlighting species-specific and community-level responses to warming events. Our third example applies spatially varying coefficient models to assess sablefish ( Anoplopoma fimbria ) biomass trends, identifying regional variability in increases in occurrence and biomass. Together, these case studies demonstrate how the surveyjoin R package and database may improve species and ecosystem assessments by providing insights into population trends across geopolitical boundaries. This database and package represent an important step toward offering a scalable framework that can be extended to include additional data types, surveys, and species. By fostering collaboration, transparency, and data-driven decision-making, surveyjoin supports international efforts to sustainably manage shared marine resources under dynamic environmental conditions.

Understanding the dynamic relationship between marine species and their changing environments is critical for ecosystem based management, particularly as coastal ecosystems experience rapid change (e.g., general warming, marine heat waves). In this paper, we present a novel statistical approach to robustly estimate and track the thermal niches of 30 marine fishes along the west coast of North America. Leveraging three long-term fisheries-independent datasets, we use spatiotemporal modeling tools to capture spatiotemporal variation in species densities. Estimates from our models are then used to generate species-specific estimates of thermal niches through time at several scales: coastwide and for each of the three regions. By synthesizing data across regions and time scales, our modeling approach provides insights into how these marine species may be tracking or responding to changes in temperature. While we did not find evidence of consistent temperature-density relationships among regions, we are able to contrast differences across species: Dover sole and shortspine thornyhead have relatively broad thermal niche estimates that are static over time, whereas several semi-pelagic species (e.g., Pacific hake, walleye pollock) have niches that are both becoming warmer over time and simultaneously narrowing. This illustrates how several economically and ecologically valuable species are facing contrasting fates in a changing environment, with potential consequences for fisheries and ecosystems. Our modeling approach is flexible and can be easily extended to other species or ecosystems, as well as other environmental variables. Results from these models may be broadly useful to scientists, managers, and stakeholders—monitoring trends in the direction and variability of thermal niches may be useful in identifying species that are more susceptible to environmental change, and results of this work can form quantitative metrics that may be included in climate vulnerability assessments, estimation of dynamic essential fish habitat, and assessments of climate risk posed to fishing communities.

Nutrient‐rich waters along the Pacific coast of North America support diverse fish communities that have helped sustain coastal peoples for millennia. Five Nuu‐chah‐nulth First Nations on the west coast of what is now known as Vancouver Island, Canada, hold constitutional Indigenous rights to conduct a multispecies community fishery, which includes Pacific Halibut (Hippoglossus stenolepis). A 2009 court decision defined the extent of these Indigenous rights to be within 9 nm of the coast, thereby not fully recognizing the knowledge and authority of the traditional leadership and raising concerns about the potential for an increase in rockfish bycatch. Yelloweye Rockfish (Sebastes ruberrimus) are a potential ‘choke’ species for this fishery because the two species occupy similar depth ranges. A choke species is one that is caught incidentally while targeting other species and, if caught in excess of its quota limits, can trigger a halt to fishing on the target species. Guided by the insights of local Indigenous peoples and using both fishery‐independent survey and commercial longline catch data, we investigated the effects of fishing depth and spatial restriction on the relative catch weights of these two species using spatiotemporal models. We find evidence that a confined fishing area can limit opportunities for avoiding choke species. Specifically, fishing at depths deeper than 175 m, which occur outside the court defined area (CDA), would provide more opportunities for catching halibut while avoiding Yelloweye Rockfish than are currently available within the CDA. This Indigenous‐informed, analytical approach to a management problem is just one example of how Western scientists can engage in coproduction of knowledge with Indigenous peoples to transition from the ‘status quo’ towards a practice of ‘Two‐Eyed Seeing’ that more effectively balances Indigenous rights and species conservation. Policy implications: Our study highlights (1) the importance of considering choke species distributions and opportunities for their avoidance when implementing spatial harvest restrictions and (2) how related analytical and management decisions can benefit from being guided by the advice of Indigenous knowledge holders. Read the free Plain Language Summary for this article on the Journal blog.

Geostatistical spatial or spatiotemporal data are common across scientific fields. However, appropriate models to analyse these data, such as generalised linear mixed effects models (GLMMs) with Gaussian Markov random fields (GMRFs), are computationally intensive and challenging for many users to implement. Here, we introduce the R package sdmTMB , which extends the flexible interface familiar to users of lme4, glmmTMB , and mgcv to include spatial and spatiotemporal latent GMRFs using an SPDE-(stochastic partial differential equation) based approach. SPDE matrices are constructed with fmesher and estimation is conducted via maximum marginal likelihood with TMB or via Bayesian inference with tmbstan and rstan . We describe the model and explore case studies that illustrate sdmTMB ’s flexibility in implementing penalised smoothers, non-stationary processes (time-varying and spatially varying coefficients), hurdle models, cross-validation and anisotropy (directionally dependent spatial correlation). Finally, we compare the functionality, speed, and interfaces of related software, demonstrating that sdmTMB can be an order of magnitude faster than R- INLA . We hope sdmTMB will help open this useful class of models to a wider field of geostatistical analysts.

Species responses to climate change are often measured at broad spatiotemporal scales, which can miss the fine‐scale changes that are most relevant to conservation and fisheries management. We develop a scaleable geostatistical approach to assess how juvenile and adult fish distributions have been shaped by changes in bottom temperature and dissolved oxygen over a recent decade of warming in the northeast Pacific. Across 38 demersal fishes, biomass trends were associated negatively with warming and positively with dissolved oxygen, but when trends in both biomass and climate were converted to velocities—the speed and direction a population would have to move to maintain consistent conditions—the effect of temperature change differed depending on local conditions. In the warmest locations, warming velocities were associated with negative biotic velocities for 19 of 69 species‐maturity combinations, and yet were almost always associated with stable or positive biotic velocities in the coolest locations (64 of 69). These spatially consistent biomass declines (negative biotic velocities) in the warmest locations and increases in cooler locations suggest a redistribution of species with the potential for new ecological and fisheries interactions. After controlling for temperature, the more spatially consistent effects of dissolved oxygen were often negative, suggesting a mechanism other than hypoxia avoidance—potentially changes in primary production. Our approach identifies the species and locations that are most sensitive to observed changes in the environment at any scale, thus facilitating future vulnerability assessments.