Evidence of stability in a chondrichthyan population

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Barnett, L. A. K., Ebert, D. A., & Cailliet, G. M. (2012). Evidence of stability in a chondrichthyan population: Case study of the spotted ratfish Hydrolagus colliei (Chondrichthyes: Chimaeridae). Journal of Fish Biology, 80(5), 1765-1788. doi:10.1111/j.1095-8649.2011.03216.x
TitleEvidence of stability in a chondrichthyan population
AuthorsL. Barnett, D. Ebert, G. Cailliet
AbstractResults presented here provide evidence of an exception to the generalization that all chondrichthyan populations are especially vulnerable to exploitation to the extent that they remain at low abundance for a protracted or indefinite duration even after exploitation rates are reduced. Delta log-normal generalized linear models (GLM) and cluster analysis of fishery-independent catch-per-unit-effort (CPUE) data from 1977 to 2006 indicated the presence of at least two distinct stocks of spotted ratfish Hydrolagus colliei off the U.S. West Coast. CPUE of the continental slope and northern continental shelf and upper slope populations did not vary between 1977 and 1995 and increased from 1995 to 2006. On the basis of the timing of these changes, it is likely that both fishing and climate influenced these trends. Sex and size-specific differences in bathymetric distribution, along with the identification of nursery sites, indicate that fishery by-catch could have a significant effect on population growth. These aggregative behaviours, combined with low fecundity, indicate that H. colliei may be vulnerable to irreversible population depletion by fisheries mortality. Temporal abundance trends indicated, however, that their population size has increased significantly within the last decade, a demonstration of population stability. A literature review indicated that there is also evidence for population stability in other chondrichthyans. The paradigm that all chondrichthyan populations fail to rebuild in response to exploitation, therefore, may not be as broadly applicable as previously thought. Thus, it is not necessarily sufficient to make generalizations regarding the vulnerability of chondrichthyans across higher taxonomic scales. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.
JournalJournal of Fish Biology
Start page1765
End page1788
Subjectsanimal, article, Atlantic Ocean, environmental protection, fish, food industry, population density, population dynamics, statistical model, statistics, United States, Animals, Conservation of Natural Resources, Fisheries, Fishes, Linear Models, Chimaeridae, Chondrichthyes, Hydrolagus colliei
NoteCited By (since 1996):1, Fish and Fisheries, CODEN: JFIBA