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Article
Annual Cycle of Primary Production in the Cariaco Basin: Response to Upwelling and Implications for Vertical Export
Journal of Geophysical Research - Oceans
  • Frank E. Muller-Karger, University of South Florida St. Petersburg
  • Ramon Varela, Estacion de Investigaciones Marinas de Margarita
  • Robert Thunell, University of South Carolina - Columbia
  • Mary Scranton, State University of New York at Stony Brook
  • Richard Bohrer, University of South Florida St. Petersburg
  • Gordon Taylor, State University of New York at Stony Brook
  • Juan Capelo, Estacion de Investigaciones Marinas de Margarita
  • Yrene Astor, Estacion de Investigaciones Marinas de Margarita
  • Eric Tappa, University of South Carolina - Columbia
  • Tung-Yuan Ho, State University of New York at Stony Brook
  • John J. Walsh, University of South Florida St. Petersburg
Document Type
Article
Publication Date
3-15-2001
Keywords
  • Cariaco Basin,
  • Caribbean Sea,
  • bacterial production,
  • oceanography,
  • marine science
Digital Object Identifier (DOI)
dx.doi.org/10.1029/1999JC000291
Disciplines
Abstract

Monthly hydrographic, primary production, bacterial production, and settling particulate carbon flux observations were collected between November 1995 and December 1997 at 10.5 degreesN, 64.67 degreesW within the Cariaco Basin, off Venezuela. Upwelling of Subtropical Underwater (SUW) started around October and lasted through approximately May of the following year. Wind speeds >7 m s(-1) were observed between January and June, with weaker winds (s(-1)) between July and December. The upwelling cycle was therefore out of phase with that of the trade winds by 2-3 months. A seasonal cycle punctuated by transient extremes associated with subsurface ventilation events was observed in primary production. High bacterial activity and organic carbon recycling rates were observed near the oxic-anoxic interface. Integrated primary production was 690 gC m(-2) yr(-1) in 1996 and 540 gC m(-2) yr(-1) in 1997. Settling carbon flux measured with sediment traps was about 5.6% of integrated primary production at 275 m and about 1.7% at 1225 m, with no seasonality in the proportion of vertical flux to primary production. In total, between 10 and 11 gC m(-2) yr were delivered to the bottom sediment of Cariaco, which suggests that between 4 x 10(5) and 1 x 10(6) t of C yr(-1) were delivered to sediments within the upwelling area of the Cariaco Basin. This represents permanent sequestration of carbon previously entrained in the North Atlantic gyre in the area of formation of SUW. Results suggests that upwelled inorganic nitrogen, rather than nitrogen fixation, is responsible for the large productivity and particulate carbon settling flux in the Cariaco Basin.

Citation / Publisher Attribution

Journal of Geophysical Research - Oceans, v. 106, no. C3, p. 4527-4542.

Citation Information
Frank E. Muller-Karger, Ramon Varela, Robert Thunell, Mary Scranton, et al.. "Annual Cycle of Primary Production in the Cariaco Basin: Response to Upwelling and Implications for Vertical Export" Journal of Geophysical Research - Oceans Vol. 106 Iss. C3 (2001) p. 4527 - 4542
Available at: http://works.bepress.com/john_walsh1/13/