widening spatio-temporal variability in the krill population structure across the scotia sea开题资料.pdf
: . r seal diets had a modal size class of 52 mm when sampled simultaneously; however, krill in the diet of seals showed a decline in size later in the season with an overall mode of 48 mm. At Bird Island, South Georgia, there was little overlap between net samples, with a modal size class of 30–40 mm, and fur seal diets, with distinct modes of 44 and 54 mm; and there was also much greater spatial variability in the size of krill in these net samples than in those from the other two locations. Extending the comparison of krill size in the diet of seals, to include spatially congruent net samples collected immediately prior to the CCAMLR 2000 Survey, showed almost complete overlap and indicated an even greater spatial variability in the krill population structure at South Georgia. Interactions between the oceanographic transport and enhanced growth rates of krill at South Georgia may combine to produce a higher degree of spatial variability in the krill population compared to other locations and this may limit the use of differences in krill length as an indicator of their provenance. This study underlines the importance of using data from multiple sources when considering large-scale krill population dynamics; information that is crucial to the effective management of the commercial exploitation of krill. r 2004 Published by Elsevier Ltd. ÃCorresponding author. Tel.: +44-1223-221607; fax +44-1223-2212539. E-mail address: k.******@ (K. Reid). 0967-0645/$ - see front matter r 2004 Published by Elsevier Ltd. doi:. IN PRESS 1276 K. Reid et al. / Deep-Sea Research II 51 (2004) 1275–1287 1. Introduction et al., 2001). Located in each of these regions are land-based CCAMLR Ecosy
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