Regional and seasonal patterns of epipelagic fish assemblages from the central California Current

Harding, Jeffrey A. and Ammann, Arnold J. and MacFarlane, R. Bruce (2011) Regional and seasonal patterns of epipelagic fish assemblages from the central California Current. Fishery Bulletin, 109(3), pp. 261-281.

PDF (The document's language is English .) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (676kB) | Preview
Official URL:


The coastal Pacific Ocean off northern and central California encompasses the strongest seasonal upwelling zone in the California Current ecosystem. Headlands and bays here generate complex circulation features and confer unusual oceanographic complexity. We sampled the coastal epipelagic fish community of this region with a surface trawl in the summer and fall of 2000–05 to assess patterns of spatial and temporal community structure. Fifty-three species of fish were captured in 218 hauls at 34 fixed stations, with clupeiform species dominating. To examine spatial patterns, samples were grouped by location relative to a prominent headland at Point Reyes and the resulting two regions, north coast and Gulf of the Farallones, were plotted by using nonmetric multidimensional scaling. Seasonal and interannual patterns were also examined, and representative species were identified for each distinct community. Seven oceanographic variables measured concurrently with trawling were plotted by principal components analysis and tested for correlation with biotic patterns. We found significant differences in community structure by region, year, and season, but no interaction among main effects. Significant differences in oceanographic conditions mirrored the biotic patterns, and a match between biotic and hydrographic structure was detected. Dissimilarity between assemblages was mostly the result of differences in abundance and frequency of occurrence of about twelve common species. Community patterns were best described by a subset of hydrographic variables, including water depth, distance from shore, and any one of several correlated variables associated with upwelling intensity. Rather than discrete communities with clear borders and distinct member species, we found gradients in community structure and identified stations with similar fish communities by region and by proximity to features such as the San Francisco Bay.

Item Type: Article
Title: Regional and seasonal patterns of epipelagic fish assemblages from the central California Current
Personal Creator/Author:
Harding, Jeffrey A.
Ammann, Arnold J.
MacFarlane, R. Bruce
Refereed: Yes
Journal or Publication Title: Fishery Bulletin
Volume: 109
Number: 3
Page Range: pp. 261-281
Date: 2011
ISSN: 0090-0656
Issuing Agency: United States National Marine Fisheries Service
Subjects: Biology
Item ID: 8706
Depositing User: Patti M. Marraro
Date Deposited: 07 Jun 2012 14:52
Last Modified: 07 Jun 2012 14:52

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...