Fixed and mixed effect models for fishery data on depth distribution of Georges Bank yellowtail flounder

• Published in: Fisheries research 2014-09, Vol.157, p.180-186
• Main Authors: Hyun, Saang-Yoon, Cadrin, Steven X., Roman, Sally
• Format: Article
• Language: English
• Subjects: Agnatha. Pisces; Animal and plant ecology; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Bottom water temperature; Catch per unit effort; Cross validation; Exploitation and management of natural biological resources (hunting, fishing and exploited populations survey, etc.); Fundamental and applied biological sciences. Psychology; Generalized linear model; Intraclass correlation coefficient; Limanda ferruginea; Pleuronectiformes; Sea water ecosystems; Skates; Synecology; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution
• ISSN: 0165-7836; 1872-6763
• DOI: 10.1016/j.fishres.2014.04.010

•Tested hypothesis that Georges Bank yellowtail flounder migrated to deeper waters during 2000–2010.•Examined effects of bottom water temperatures and other species on depth distribution of Georges Bank yellowtail flounder.•Applied a mixed effect model because of a correlation between haul-catches.•The mixed effect model was more parsimonious than the fixed effect model.•The fixed effect model outperformed the mixed effect model in goodness of fit and prediction. Fishermen reported that Georges Bank yellowtail flounder (Limanda ferruginea) migrated to deeper waters during 2000–2004 and 2006–2010. To test this hypothesis, we analyzed fishery data from otter trawl vessels targeting a mixed groundfish complex over the 10 year period, using a statistical linear model with catch-per-unit-effort weighted depth as the response variable, and abiotic (e.g., bottom water temperature) and biotic (e.g., skate and dogfish catch) data as predictor variables. We considered mixed as well as fixed effect models to account for dependence or correlation in catches among hauls within a trip. Yellowtail flounder shifted to deeper waters during the 10 years. Bottom water temperature had a greater influence on the movement than the distribution of skate or dogfish. Optimal water temperature was about 6.8°C from the fixed effect model and about 7.1°C from the mixed effect model. Skate distribution affected yellowtail flounder depth more than dogfish distribution. The mixed effect model was more parsimonious than the fixed effect model, although the latter fitted the data better and performed better under cross validation.