Shipe, R. F. Department of Ecology, Evolution and Marine Biology, shipe@lifesci.ucsb.edu
Brzezinski, M. F. Department of Ecology, Evolution and Marine Biology, brzezins@lifesci.ucsb.edu
Franck, V. M. Department of Ecology, Evolution and Marine Biology, franck@lifesci.ucsb.edu
Varela, D. E. Department of Earth and Ocean Sciences, varela@unixg.ubc.ca
Harrison, P. J. Department of Earth and Ocean Sciences, pharrisn@unixg.ubc.edu

 
BIOGENIC SILICA PRODUCTION ALONG THE EASTERN MARGIN OF THE NORTH PACIFIC GYRE
 
Biogenic silica production along the eastern boundary of the North Pacific Ocean was studied on four cruises. Profiles of silica production rates were obtained in the Santa Barbara Channel, the Monterey Bay region and the continental margin of Vancouver Island. In addition, a transect of surface-only measurements was conducted from Monterey to Vancouver. All data was collected during spring under upwelling favorable conditions (highest surface silicic acid concentrations >10 uM at each site) and specific rates of silica production often implied doubling times < 1 d. Kinetic experiments indicate that significant limitation of biogenic silica production by low silicic acid concentrations occurs in each study area. The mean surface silica production rate during the four cruises was 1.6 mmol m-2 d-1. Mean integrated Si production rates were 30, 205 and 14 mmol m-2 d-1 in the Santa Barbara Channel, Monterey Bay area and Vancouver Island coastal current, respectively. These rates are comparable to Si production rates in the upwelling zones of Peru and West Africa (surface mean = 2.3 mmol m-2 d-1; integrated mean = 46 mmol m-2 d-1) indicating that high rates of silica production are more widespread along eastern boundary margins than previously thought.
 
Day: Friday, Feb. 5
Time: 04:30 - 04:45pm
Location: Sweeney Center
 
Code: SS13FR0430S