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Title: Preliminary report to IDOE on the possible effects of the Ceratium tripos bloom, in the New York Bight, March--July 1976. [Effects of dinoflagellate respiration on rate of oxygen depletion]

Conference ·
OSTI ID:7330281

From March to July 1976, the occurrence of a subsurface chlorophyll a maximum at a depth of ca. 30m, over a large area of the New York Bight, extending from the eastern end of Long Island, New York to southern New Jersey, was attributed, in large part, to the predominance of the dinoflagellate, Ceratium tripos. Direct evidence from field observations indicates the organism is capable of reducing inorganic carbon, in the presence of light, and has light-independent nitrate reductase activity. However, the maximum abundance of C. tripos was observed below the 0.3 percent light depth, which is coincident with the base of the thermocline. While it is probable that the cells in the overlying mixed layer are autotrophic, the majority of the population, below the compensation depth, and thermocline is suggested to be capable of phagotrophy. Observations of particle ingestion by Ceratia have been published. The sulcal opening in C. tripos is ca. 20 ..mu.. wide (Falkowski, unpublished data) and similar to the opening of C. lunula, a species known to be phagotrophic (Norris, 1969). If the myxotrophic hypotheses are true, the organisms below the thermocline did not contribute to the net productivity of the water column directly. Consequently, net community respiration below the thermocline would reduce the oxygen content of the bottom water. If the respiration rate of the Ceratia exceeded the renewal of oxygenated water, the net loss of oxygen could contribute to local pockets of low O/sub 2/. These regions would appear where benthic respiration was high, and/or there was little physical mixing. A computer simulation model was built to explore the combined effects of benthic respiration and Ceratium respiration on the rate of oxygen depletion below the thermocline.

Research Organization:
Brookhaven National Lab., Upton, NY (USA)
Sponsoring Organization:
USDOE
DOE Contract Number:
EY-76-C-02-0016
OSTI ID:
7330281
Report Number(s):
BNL-21944; CONF-760908-3
Resource Relation:
Conference: Ocean 76 symposium, Washington, DC, USA, 13 Sep 1976
Country of Publication:
United States
Language:
English