A spatial-temporal model for snow crab (Chionoecetes opilio) stock size in the Southern Gulf of St. Lawrence

• Main Authors: Cadigan, Noel G, Wade, Elmer, Nielsen, Anders
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: NRC Research Press (a division of Canadian Science Publishing) 2016
• Subjects: Canada; Chionoecetes opilio; Snow crab
• Online Access: http://hdl.handle.net/1807/77148; http://www.nrcresearchpress.com/doi/abs/10.1139/cjfas-2016-0260

We develop a high resolution spatio-temporal model of stock size and harvest rates for snow crab (Chionoecetes opilio) in the Southern Gulf of St. Lawrence, which supports an economically important fishery off the east coast of Canada. It is a spatial and weekly model during 1997-2014 that utilizes within-season depletion based on catch per unit of effort (CPUE; kg per pot), and also biomass values from a survey designed specifically for this stock. The model is formulated in a state-space framework. The main contribution of the model is to provide a better understanding of fishery-dependent factors that affect CPUE. There is strong evidence of density-dependence in the relationship with CPUE and stock biomass, in addition to a general increase in CPUE catchability over time that may be related to changes in gear soak time, and spatial variation in catchability. We also find that a natural mortality rate of 0.4 provides a better fit to survey results. Model results suggest that there is no evidence of effort saturation in the fishery. The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author.