• Login
    View Item 
    •   Oxy Scholar Home
    • Bulletin of the Southern California Academy of Sciences
    • Bulletin of the Southern California Academy of Sciences
    • View Item
    •   Oxy Scholar Home
    • Bulletin of the Southern California Academy of Sciences
    • Bulletin of the Southern California Academy of Sciences
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Megabenthic Assemblages of Coastal Shelves, Slopes, and Basins off Southern California

    Thumbnail
    Subject
    Megabenthic Assemblages; Coastal Shelves; Slopes; Basins; Southern California
    Author
    Thompson, Bruce; Tsukada, David; Laughlin, Jimmy
    Journal Title
    Scas: Bulletin of the Southern California Academy of Sciences
    Volume
    92
    Issue
    scas/vol92/iss1; 1
    Metadata
    Show full item record
    URI
    https://scholar.oxy.edu/handle/20.500.12711/9685
    Abstract
    Megabenthic invertebrate assemblages from soft sediments on the <br /><br />mainland shelf and San Pedro and Santa Monica Basin slopes and floor were <br /><br />identified based on 1203 otter trawl collections made between 1971 and 1985 at <br /><br />depths ranging from 10 to 915 m. Major changes in species composition and <br /><br />abundances occur at mid-slope (~300 m) and at the basin sills (~715 m). The <br /><br />mainland shelf assemblage (10-1 37 m) is dominated by the sea urchin Lytechinus <br /><br />pictus and the prawn Sicyonia ingentis. This assemblage is heterogeneous in space <br /><br />and time, with sub-assemblages that reflect severe contamination and large storms <br /><br />and/or El Nino. The basin slopes are dominated by the echinoids, Allocentrotus <br /><br />fragilis, Brissopsis pacifica, and Brisaster latifrons. The latter two species may exist <br /><br />in kilometer scale herds on the slopes, but they are absent below the basin sills <br /><br />(737 m). Galatheid crabs are the most abundant megafauna in the San Pedro and <br /><br />Santa Monica Basins. Species composition of all assemblages appeared to be <br /><br />seasonally stable, but 6". ingentis and the tuna crab Pleuroncodes planipes increased <br /><br />by several orders of magnitude during El Nino. Numbers of megafaunal species, <br /><br />individuals, and biomass were highest on the basin slopes reflecting elevated levels <br /><br />of organic material in the sediment. Numbers of individuals and biomass increased <br /><br />on the lower slopes (500-800 m), following El Nino. Although organic material <br /><br />is highest in the basins, the numbers of species and individuals were much lower <br /><br />than on the lower slopes. Near anaerobic conditions in the basins probably exclude <br /><br />many species.
    Collections
    • Bulletin of the Southern California Academy of Sciences

    Browse

    All of Oxy ScholarCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsJournal TitleJournal IssueThis CollectionBy Issue DateAuthorsTitlesSubjectsJournal TitleJournal Issue

    My Account

    LoginRegister

    DSpace software copyright © 2002-2021  DuraSpace
    Contact Us | Send Feedback
    DSpace Express is a service operated by 
    Atmire NV