Distribution and life-history of spurdog (Squalus acanthias) along the Norwegian coast inferred from a five-year fishery-independent longline survey

Distribution and life-history of spurdog (Squalus acanthias) along the Norwegian coast inferred from a five-year fishery-independent longline survey | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Distribution and life-history of spurdog (Squalus acanthias) along the Norwegian coast inferred from a five-year fishery-independent longline survey Aurélien Delaval, Hector Andrade, Tine Nilsen, Tone Vollen, Rosario Lavezza, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8583209/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract Northeast Atlantic spurdog ( Squalus acanthias ) has recently shown signs of recovery from overfishing following international conservation measures. As the fishery slowly reopens, ensuring its sustainable long-term trajectory will require an understanding of its contemporary population structure, habitat use, and life-history traits across its distribution range. Here, we used biological data collected during an annual autumn (September-October) longline survey from 2021–2025 along the southwestern coast of Norway to investigate sex, maturity, and age-related distributions and life-history traits of spurdog in the region. Spurdog catches (N = 7,492) included all life-stages for both sexes, including juveniles and sexually active adults, across the entire survey area from Rørvik (65°N) to the Swedish border. Spurdog abundance was consistently higher in shallow waters (< 150 m) off the coasts of Rogaland (58–60°N), northern Vestlandet and Møre og Romsdal (61–63°N) counties, where we encountered sex- and maturity-biased aggregations often dominated by gravid females or sexually active males. Survey coverage in the Skagerrak was more limited but also indicated potentially important habitats to the east. Growth and maturity parameters were within the ranges reported in other areas of the stock, and uterine fecundity was positively correlated to maternal size and age. The fecundity-length relationship, which has historically fluctuated in response to density-dependent effects and fishing pressure, was indicative of a recovering stock. The survey establishes a new reference point for spurdog in a biologically productive region that has not been covered by other surveys, and provides a foundation for long-term monitoring of a historically important fishery resource. Elasmobranch spiny dogfish Squalus acanthias distribution life-history longline Full Text Additional Declarations No competing interests reported. The Institute of Marine Research was granted dispensation from the regulatory ban on fishing for spurdog (regulation number FOR-2013-12-13-1507, § 2) by the Norwegian Directorate of Fisheries, in accordance with the Act on the Management of Wild Marine Resources (act number LOV-2008-06-06-37, § 66). Supplementary Files Norwegianspurdogdistributionandlifehistorysupplementarymaterial.docx Cite Share Download PDF Status: Under Review Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8583209","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":589713882,"identity":"e6754166-6485-4ba6-b59a-ba396eb4869b","order_by":0,"name":"Aurélien 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As the fishery slowly reopens, ensuring its sustainable long-term trajectory will require an understanding of its contemporary population structure, habitat use, and life-history traits across its distribution range. Here, we used biological data collected during an annual autumn (September-October) longline survey from 2021\u0026ndash;2025 along the southwestern coast of Norway to investigate sex, maturity, and age-related distributions and life-history traits of spurdog in the region. Spurdog catches (N\u0026thinsp;=\u0026thinsp;7,492) included all life-stages for both sexes, including juveniles and sexually active adults, across the entire survey area from R\u0026oslash;rvik (65\u0026deg;N) to the Swedish border. 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