Application of generalized additive models to examine ontogenetic and seasonal distributions of spiny dogfish ( Squalus acanthias) in the Northeast (US) shelf large marine ecosystem

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Authors: Sagarese, Skyler R., Frisk, Michael G., Cerrato, Robert M., Sosebee, Kathy A., Musick, John A., Rago, Paul J.
• Other Authors: Trenkel, Verena
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 2014
• Subjects: spiny dogfish; Squalus acanthias
• Online Access: http://dx.doi.org/10.1139/cjfas-2013-0342; http://www.nrcresearchpress.com/doi/full-xml/10.1139/cjfas-2013-0342; http://www.nrcresearchpress.com/doi/pdf/10.1139/cjfas-2013-0342

Increased commercial importance of spiny dogfish (Squalus acanthias) combined with an often debated, and controversial, ecological impact has warranted an investigation of the relationship among distribution, environment, and prey to better understand the species ecology and inform management. To elucidate mechanisms behind distributional changes, we modeled seasonal occurrence and abundance of neonate, immature, and mature spiny dogfish as functions of abiotic and biotic factors using generalized additive models and Northeast Fisheries Science Center bottom trawl survey data. Significant nonlinear relationships were widespread throughout dogfish stages and seasons. Seasonal occurrence was tightly linked to depth and bottom temperature, with year and Julian day influential for some stages. While these factors also influenced abundance, ecological factors (e.g., squid abundances) significantly contributed to trends for many stages. Potential impacts of climate change were evaluated by forecasting distributions under different temperature scenarios, which revealed higher regional probabilities of occurrence for most stages during a warmer than average year. Our results can be used to better understand the relationship between sampling periods and movement drivers to survey catchability of the population in the Northeast (US) shelf large marine ecosystem.