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Marine spatial planning and conservation initiatives benefit from an understanding of species distributions across larger geographic areas than are often sampled by any one survey. Here, we test whether the integration of disparate survey data can improve habitat predictions across a region not well sampled by a single survey using Dungeness crab (Metacarcinus magister) from British Columbia as a case study. We assemble data from dive, trawl, and baited-trap surveys to generate six candidate generalized linear mixed-effect models with spatial random fields. To compare single-survey and integrated models, we evaluate predictive performance with spatially buffered leave-one-out cross-validation and independently with two novel approaches using fisheries catch data. We find improved predictive performance and reduced uncertainty when integrating data from surveys that suffer from small sample size, low detectability, or limited spatial coverage. We demonstrate the importance of robust model evaluation when integrating data and predicting to unsampled locations. In addition, we highlight the need for careful consideration of sampling biases and model assumptions when integrating data to reduce the risk of prediction errors. Key words: species distribution modelling, data integration, Gaussian random fields, Dungeness crab, 1. Introduction Species distribution models (SDMs), which relate species observations to environmental covariates, can be used to generate predictions in unsampled areas to inform a variety of management and conservation [...]

Predictions of the distribution of groundfish species are needed to support ongoing marine spatial planning initiatives in Canadian Pacific waters. Data to inform species distribution models are available from several fishery-independent surveys. However, no single survey covers the entire region and different gear types are required to survey the range of relevant habitat. Here, we demonstrated a method for integrating presence-absence data across surveys and gear types that allows us to predict the coastwide distributions of 65 groundfish species in British Columbia. Our model leverages data from multiple surveys to estimate how species respond to environmental gradients while accounting for differences in survey catchability. We find that this method has two main benefits: (1) it increases the accuracy of predictions in data-limited surveys and regions while having negligible impacts on accuracy when data are already sufficient, and (2) it reduces uncertainty, resulting in tighter confidence intervals on predicted occurrences. These benefits are particularly relevant in areas of our coast where our understanding of habitat suitability is limited due to a lack of spatially comprehensive long-term groundfish surveys. Key words: demersal fish, species distribution modelling, integrated model, spatiotemporal random field, species richness, Introduction Coastwide predictions of the distribution of groundfish species are needed to support ongoing marine spatial planning (e.g., PNCIMA 2017) and oil spill response planning in Canada's Pacific Region. Data [...]

To protect cold-water corals and sponges from fishing damage, management changes were made in 2012 to the groundfish bottom trawl fishery British Columbia, Canada. The Groundfish Trawl Habitat Agreement restricted the spatial footprint of the fishery and introduced a cold-water coral and sponge bycatch quota, which was among the world's first. Using 12 years of catch records from the fishery, we found a 31% decrease in overall frequency of encounters of cold-water coral and sponge, a 76% decrease in mean catch weight, and an 89% decrease in total annual catch. We tracked changes in the relative utilization of fine-scale fishing grounds ('fishing opportunities') and found evidence of active avoidance of areas with high cold- water coral and sponge density. The habitat agreement appears overall to have been successful at reducing impacts to cold-water coral and sponge, although we identified several areas of potential conservation concern where effort and catch have not decreased. Nonspatial management measures in a complex multispecies fishery can result in spatial changes in fishing behaviour, with positive conservation outcomes for bycatch species. Afin de proteger les coraux et eponges d'eau froide des dommages causes par la peche, des changements ont ete apportes en 2012 a la gestion de la peche aux poissons demersaux au chalut de fond en Colombie-Britannique (Canada). Le Groundfish Trawl Habitat Agreement (accord sur la protection de l'habitat des poissons de fond vises par le chalutage) restreint l'empreinte spatiale de cette peche et introduit un quota de prises accessoires de coraux et d'eponges d'eau froide, une de premieres mesures du genre dans le monde. A la lumiere des registres de prises de cette peche sur 12 annees, nous relevons une baisse de 31 % de la frequence globale d'observations de coraux et d'eponges d'eau froide, une baisse de 76 % de la masse moyenne des prises et une baisse de 89 % des prises annuelles totales. En suivant les variations de l'utilisation relative de lieux de peche a petite echelle (les << possibilites de peche >>), nous relevons des indices d'evitement actif de lieux de forte densite de coraux et d'eponges d'eau froide. Si, en general, l'accord sur l'habitat semble reduire les impacts sur les coraux et eponges d'eau froide, nous cernons plusieurs zones potentiellement preoccupantes en matiere de conservation ou l'effort et les prises n'ont pas diminue. Des mesures de gestion non spatiales dans une peche multispecifique complexe peuvent produire des modifications des comportements de peche dans l'espace qui se traduisent par des resultats positifs pour la conservation d'especes de prises accessoires. [Traduit par la Redaction], 1. Introduction Cold-water corals and sponges (CWCS) provide important benthic habitat for a diverse group of fish and invertebrates (Chu and Leys 2010; Henderson et al. 2020), and have roles [...]