Contact InformationFisheries Academic Program
217 Lena Point bldg.
17101 Pt. Lena Loop Rd.
Juneau, AK 99801
Phone: (907) 796-5462
Fax: (907) 796-5447
Joel WebbPh.D. Student
Development of biological reference points for exploited stocks of Tanner (Chionoecetes bairdi) and snow crab (Chionoecetes opilio) in Alaska
- B.S. 2000 University of Washington (Fisheries)
- M.S. 2006 University of Alaska Fairbanks (Fisheries)
Management of crab fisheries is complicated by uncertainty in stock-recruit relationships, high temporal variability in abundance, heterogeneous distributions, and difficulty in aging. Given these uncertainties a primary management goal has been to maintain population reproductive potential, but there is a current lack of knowledge of patterns of spatiotemporal variability in reproductive potential and segements of the mature population which may contribute disproportionately to total reproductive output. Two direct measures of population reproductive potential are the number of viable eggs produced by females and the number of sperm transferred by males to females. Population viable egg production is an estimate of the reproductive contribution of the population to the next generation, while the number of sperm transferred to females by males during mating is an index of female “exposure” to males through their reproductive history. In addition to development of indices of reproductive potential two factors which contribute to uncertainty in measurement of variability in reproductive potential are limited understanding of the issues of spatial variability (e.g. scale of measurement) and application of measures to crab with varying spans of reproductive history at the time of measurement (e.g. accrual of sperm reserves and potential variability in viable egg production for females having completed one versus two or more reproductive cycles). My research seeks to evaluate patterns of spationtemporal variability in reproductive potential, possible relationships between reprodcutive potential and recruitment, and development of biological references points for fisheries management.
Current Research Projects
- Indices of reproductive potential and biological reference points for eastern Bering Sea snow crab, Chionoecetes opilio
- Spatial structure in relation to benthic habitat for Tanner crab, Chionoecetes bairdi, in Glacier Bay, Alaska
- Variability in reproductive potential among exploited stocks of Tanner crab in Southeast Alaska
Swiney, K.M., J.B. Webb, G.H. Bishop, and G.L. Eckert. 2010. Temporal and Spatial Variability of Alaska Red King Crab Fecundity, and Accuracy of Clutch Fullness Indices in Estimating Fecundity. Pages 265-282 in Kruse, G.H., G.L. Eckert, R.J. Foy, R.N. Lipcius, B. Sainte-Marie, D.L. Stram, and D. Woodby (eds.). Biology and Management of Exploited Crab Populations under Climate Change. Alaska Sea Grant College Program, University of Alaska Fairbanks, Fairbanks
Webb, J.B. 2009. Reproductive success of multiparous female Tanner crab (Chionoectes bairdi) fertilizing eggs with or without recent access to males. Journal of Northwest Atlantic Fisheries Science 41:163-172
Webb, J.B. and J. Bednarski. 2010. Variability in reproductive potential among exploited stocks of Tanner crab, Chionoecetes bairdi, in southeast Alaska. Pages 295-317 in Kruse, G.H., G.L. Eckert, R.J. Foy, R.N. Lipcius, B. Sainte-Marie, D.L. Stram, and D. Woodby (eds.). Biology and Management of Exploited Crab Populations under Climate Change. Alaska Sea Grant College Program, University of Alaska Fairbanks, Fairbanks.
Zheng, J., L.M. Slater, J. Webb, and G. Bishop. 2011. The current status of biological knowledge relating to the management of fisheries for Tanner (Chinoecetes bairdi, Rathbun, 1924) and snow crabs (Chinoecetes opilio, Fabricius, 1788) in Alaskan waters. pp. 127-138 in New Frontiers in Crustacean Biology, edited by A. Asakura. Crustaceana Monographs v. 15 Brill, NV, Leiden, 2011. 360 p.