Northwest Fisheries Science Center

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Document Type: Journal Article
Center: NWFSC
Document ID: 1917
Title: Variation in age and growth of greenstriped rockfish (sebastes elongatus) along the U.S. West Coast (Washington to California)
Author: A. A. Keller, Kyle J. Molton, Allan C. Hicks, M. A. Haltuch, Chantel R. Wetzel
Publication Year: 2012
Journal: Fisheries Research
Abstract: Greenstriped rockfish, Sebastes elongatus, are a common commercial and recreational species often taken as by catch in commercial west coast fisheries. We evaluated weight-length relationships and size-at-age using von Bertalanffy growth models for greenstriped rockfish sampled along the U.S. west coast from 2003 to 2008. Based on regression analyses, populations were subdivided into two depth strata (55 -122 m and 122 - 450 m) and four geographic regions (48°10N  48°28N, 40°26N  48°10N, 34°27N  40°26N and 32°30N  34°27N) and differences in length, age and growth examined by gender. Strong evidence of variation in weight-length relationships was found north and south of Cape Mendocino (40°26N) but little variation was noted for depth or gender. In contrast, variations in von Bertalanffy growth models were highly dimorphic between sexes with consistent patterns across depth and geographic regions. Females grew more slowly and reached larger asymptotic sizes (L, cm) relative to males in all regions examined. Asymptotic size for both males and females tended to increase at higher latitude and increased depth; however the smallest asymptotic sizes occurred in the region from Pt. Conception to Cape Mendocino, CA (34°27N  40°26N), rather than lower latitudes south of Pt. Conception (32°30N  34°27N). Greenstriped rockfish growth rates (k, yr-1) exhibited a more complex pattern. Higher growth rates were associated with regions within the northern California Current system characterized by high productivity.