Journal Article

On the relation between schools, clusters of schools, and abundance in pelagic fish stocks

P. Petitgas, D. Reid, P. Carrera, M. Iglesias, S. Georgakarakos, B. Liorzou and J. Massé

in ICES Journal of Marine Science

Published on behalf of ICES/CIEM

Volume 58, issue 6, pages 1150-1160
Published in print January 2001 | ISSN: 1054-3139
Published online January 2001 | e-ISSN: 1095-9289 | DOI:
On the relation between schools, clusters of schools, and abundance in pelagic fish stocks

More Like This

Show all results sharing these subjects:

  • Environmental Science
  • Marine and Estuarine Biology


Show Summary Details


Small pelagic fish are known to aggregate into schools and clusters of schools. It is commonly assumed that the number of such schools and clusters, as well as their size and densities, will vary with the stock abundance. We have carried out a PCA based meta-analysis, using series of acoustic survey data from five different locations in Europe to examine this assumption. The study concluded that there was no discernible relationship between stock abundance and the number of schools seen, or on the clustering of those schools. The study also showed that the number and structure of the school clusters was strongly correlated with the number of schools seen. An increased number of schools in an area tended to be linked with denser clusters (more schools per kilometre) and a higher occupation of the survey area by those clusters. There was also a weaker tendency to find more clusters. It is not clear whether these relationships and the absence of a link to abundance are due to density independence in aggregation patterns or whether such density dependence is only functional at relatively low stock abundance levels.

Keywords: small pelagics; acoustic surveys; schools; clusters; aggregation; density dependence; PCA with passive variables; meta-analysis

Journal Article.  0 words. 

Subjects: Environmental Science ; Marine and Estuarine Biology

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.