Characterization of the pelagic fish community of the north‐western and northern Spanish shelf watersa. Issue 4 (31st May 2013)

• Record Type: Journal Article
• Authors: Santos, M. B.; González‐Quirós, R.; Riveiro, I.; Iglesias, M.; Louzao, M.; Pierce, G. J.
• Is Part Of: Journal of fish biology. Volume 83:Issue 4(2013)
• Page Start: 716
• Page End: 738
• Publication Date: 2013-05-31
• Subjects: Fishes -- Periodicals; Fishes -- Great Britain -- Periodicals; 597
• DOI: 10.1111/jfb.12107
• Languages: English
• ISSNs: 0022-1112

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>This study demonstrates the utility of trawl data, collected during acoustic surveys of pelagic fish stocks as a way of confirming fish identification, to characterize the pelagic community, as well as allowing description and prediction of fish distribution patterns, based on data from Spanish Atlantic Ocean shelf surveys during spring 2005–2011. The composition of the pelagic community is described, as well as spatial and temporal patterns of variation in both the community composition and the presence and importance of two of the main exploited pelagic species, sardine <italic>Sardina pilchardus</italic> and anchovy <italic>Engraulis encrasicolus</italic>. The most important species in terms of both frequency of occurrence and standardized mass in hauls were mackerel <italic>Scomber scombrus</italic>, hake <italic>Merluccius merluccius</italic>, horse mackerel <italic>Trachurus trachurus</italic>, <italic>S. pilchardus</italic> and bogue <italic>Boops boops</italic>. Multivariate analysis indicated significant effects of depth, geographical area and year on haul composition. Descriptive generalized additive models (GAM), with latitude, longitude and depth as predictors, identified clear spatial patterns in the occurrence and abundance of both <italic>S. pilchardus</italic> and <italic>E. encrasicolus</italic>, with abundance being highest closer to the coast and, in the case of <italic>E. encrasicolus</italic>, higher near the French and Portuguese borders. Further GAM analysis, using environmental variables to explain spatial patterns, revealed significant effects of depth and sea surface temperature (SST) gradient and depth on <italic>S. pilchardus</italic> importance, while <italic>E. encrasicolus</italic> importance was related to SST. The importance of both species in hauls was higher in the years of higher spawning stock biomass (SSB) and <italic>E. encrasicolus</italic> also appeared to expand its range when SSB was higher.</p> </abstract>