Biological aspects of demersal fish assemblages in central California submarine canyons

The Center for Habitat Studies was contracted by the National Fish and Wildlife Foundation and Monterey Bay Sanctuary Monitoring Program (SIMoN) to determine species composition, diversity, and habitat associations of commercially important groundfishes in central California submarine canyons. Surficial substrate maps of the headward parts of Ascension and Partington Canyons were created using previously collected multibeam bathymetric and backscatter imagery and used to determine biological survey design. Seafloor features depicted on the habitat maps were documented (“groundtruthed”) and groundfishes were identified and enumerated using a manned submersible. In Ascension Canyon, 2,839 fishes from at least 47 species, including 21 rockfish species, were reported among 32 transects conducted in 2001. Stripetail (Sebastes saxicola) rockfishes were the dominant fish species at 200 and 250 m, whereas flatfishes (e.g., Glyptocephalus zachirus, Microstomus pacificus) were dominant at 300 and 350 m. Species diversity was greatest at 300 and 350 m, and was significantly greater on the south side of the canyon than on the north side, probably because of more varied habitat types in the former region. In Partington Canyon, 3,389 fishes comprising 48 species, including 27 rockfish species, were documented from 16 transects conducted in 2003. Rockfishes were dominant at all depths but species distribution varied with depth. Species diversity was greatest at 250 m in this region. Habitat associations of dominant fishes were additionally determined in each location. Results are being utilized as part of SIMoN’s monitoring efforts and have direct implications for habitat-based management and the establishment of marine protected areas off California. A manuscript detailing results is in preparation.

 

Top | About Us | Site Map | Privacy Policy | Contact US | ©2004 Center for Habitat Studies