00000nam 2200000za 4500 9.805253 CaOODSP 20221107135615 cr ||||||||||| 150406s1999 oncdb ob f000 0 eng d CaOODSP eng eng fre n-cn--- Fs70-1/1999-115E-PDF Chen, Yong, 1963- Developing an overall indicator for monitoring temporal variation in fish size at age and its application to cod (Gadus morhua) in the northwest Atlantic, NAFO subdivision 3Ps [electronic resource] / Yong Chen and Luiz G. S. Mello. Ottawa : Fisheries and Oceans Canada, 1999. 16 p. : fig., graphs, maps, tables. Canadian Stock Assessment Secretariat research document, 1480-4883 ; 99/115 Includes bibliographical references (p. 10-11). In this study, principal component analysis (PCA) is proposed to summarize size-at-age data. Because fisheries data tend to be subject to atypical errors, a two-step procedure is proposed: a robust multivariate approach is applied to size-at-age data to identify outliers in data, and then a weighted PCA is applied with the defined outliers down-weighted. The resultant principle components (PCs) are interpreted with respect to the original variables. An indicator is identified from the resultant PCs for monitoring temporal variations in size-at-age data. The proposed approach is applied to size-at-age data of cod (Gadus morhua) in the Northwest Atlantic, NAFO subdivision 3Ps. An overall size-at-age indicator is developed for the cod stock. gccst Fisheries resources gccst Salt water fish gccst Fishing area gccst Fisheries management Mello, Luiz G. S. Canada. Department of Fisheries and Oceans. Canada. Canadian Stock Assessment Secretariat. Canadian Stock Assessment Secretariat research document, 1480-4883 ; 99/115 (CaOODSP)9.507740 PDF 1.38 MB https://publications.gc.ca/collections/collection_2015/mpo-dfo/Fs70-1-1999-115-eng.pdf