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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Life-history organization of herring (Clupea harengus pallasi) in the northeast Pacific

Aleaziz, Farzad 14 November 1996 (has links)
The distribution of herring (Clupea harengus pallasi) in the Northeast Pacific extends from southern California to northern Alaska. Studies on variation in herring life-history are limited to local characteristics and recruitment populations or relatively restricted regions of the Northeast Pacific. In this study I assessed herring life-history patterns and recruitment variation among 14 sites extending from Lynn Channel in Alaska to San Francisco Bay in California. Biological data were compiled from published and of state and provincial unpublished technical reports fisheries agencies in the northeast Pacific. Multivariate (PCA) and inferential statistical methods were applied in data analysis. Ordinations of length-and weight-at-age revealed no latitudinal patterns among the 14 herring sites. Among four sites for which environmental data were available, there were significant negative correlations between first PC scores of size and Ekman layer transport and sea-surface salinity (SSS). Reproductive characteristics of herring appeared to vary latitudinally. Herring from the more southerly sites tended to mature at an earlier age and smaller size and have a longer duration of spawning than herring from northerly sites. There were significant negative first PC scores of reproductive correlations between variables and Ekman transport, sea-surface temperature, and SSS. With the exception of Lynn and Seymour Channels in Alaska, the most northerly sites in this study, asymptotic to northern size (L[subscript]���) tended to increase from southern latitudes. With the exception of southern Strait of Georgia (British Columbia) herring and Tomales Bay (California) herring, growth coefficients (K) appeared to be higher in latitudes. L[subscript]��� was negatively correlated with SST. Recruitment variation at three sites was related to Ekman layer transport during the periods of spawning. At San Francisco Bay recruitment was negatively related to winter Ekman transport. At Sitka and Island, recruitment showed a southwestern Vancouver significant positive and negative correlation, respectively, Recruitment in northern and with spring Ekman transport. southern Strait of Georgia were negatively correlated with SST during fall. There was no correlation between recruitment and SSS for all sites. / Graduation date: 1997

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