HR: 16:00h
AN: OS52H-07    [PDF]
TI: A Coupled Spatial Pattern of Benthic and Pelagic Ecosystem Structure in Coastal Upwelling Regions
AU: * Kinlan, B P
EM: kinlan@lifesci.ucsb.edu
AF: Marine Science Institute, University of California Santa Barbara, Mailcode #9610, Santa Barbara, CA 93106-9610 United States
AU: Broitman, B R
EM: broitman@lifesci.ucsb.edu
AF: Marine Science Institute, University of California Santa Barbara, Mailcode #9610, Santa Barbara, CA 93106-9610 United States
AB: A growing body of research in the benthic environment has revealed that coastal oceanographic processes largely determine the structure of ecological communities in the nearshore. Knowledge of the spatial pattern of coupled benthic-pelagic processes is of critical importance to coastal management issues and to our understanding of nearshore ecological systems. Yet, rigorous characterization of the spatial scales of benthic-pelagic coupling has remained elusive. We studied patch scales of benthic and pelagic primary productivity over a large region on the west coast of North America, between Baja California del Sur, Mexico (27$\deg$N) and Oregon, USA (42$\deg$N). Benthic patch scales were determined using the alongshore distribution of shallow subtidal kelp stands from aerial photography. Nearshore pelagic patch scales were examined through chlorophyll-a concentration from SeaWiFS. The spatial analysis showed a striking match between the patch scales of kelp stands and chlorophyll-a concentration. Across this large extent of coastline ($\sim$3000 km) coastal patch scales are characterized by small-scale spatial cycles of 30-60 km embedded in large 150-250 km regions. A spatial analysis of meridional anomalies in coastline orientation across the region shows that patch scales in the benthic and pelagic patterns closely follow the spatial pattern of coastline orientation. Our results suggest the existence of nested spatial scales of variation in nearshore ocean climate with strong, predictable effects on benthic and pelagic ecosystems. The correlated spatial patterns provide strong support for topographic forcing of nearshore oceanography as the dominant process structuring coastal ecosystems in this upwelling region. Moreover, the existence of well-defined spatial scales and a mechanistic linkage to physical forcing provides a powerful tool for current coastal management initiatives.
DE: 4516 Eastern boundary currents
DE: 4520 Eddies and mesoscale processes
DE: 4546 Nearshore processes
DE: 4815 Ecosystems, structure and dynamics
DE: 9355 Pacific Ocean
SC: Ocean Sciences [OS]
MN: 2004 Ocean Sciences Meeting