Regeneration of nitrogen by the nekton and its significance in the northwest Africa upwelling ecosystem

Journal Article · Fri Jan 01 04:00:00 EST 1982 · Fish. Bull.; (United States)

OSTI ID:5848057

Whitledge, T E

Nitrogen and phosphorus excretion rates were measured for octopus and six species of fish in the northwest Africa upwelling region near lat. 21/sup 0/40'N. The nekton excretion rates ranged for 0.44 to 4.61 ..mu..g NH/sub 4/-N/mg dry weight per day and the whole body C:N (by atoms) of the specimens was 4.85. The calculated nitrogen turnover time in the well-fed specimens was about 65 days. The estimated rates of ammonium regeneration over the shelf (<200m) for all the nekton was about 3 mg-at/m/sup 2/ per day which was 27% of the phytoplankton ammonium uptake requirements. On the slope (>200m) the nekton regenerated 1.8 mg-at/m/sup 2/ per day which was 11% of phytoplankton ammonium uptake. The ammonium production by bacterioplankton, zooplankton, nekton, and sediments accounted for 226% of the ammonium utilized in the nearshore shelf region and 83% in the offshore region.

• Research Organization: Brookhaven National Lab., Upton, NY
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5848057
• Journal Information: Fish. Bull.; (United States), Journal Name: Fish. Bull.; (United States) Vol. 80:1; ISSN FSYBA
• Country of Publication: United States
• Language: English

Related Subjects

520100 -- Environment
Aquatic-- Basic Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
560305* -- Chemicals Metabolism &amp; Toxicology-- Vertebrates-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AFRICA
ANIMALS
AQUATIC ECOSYSTEMS
AQUATIC ORGANISMS
CLEARANCE
COASTAL WATERS
CONTINENTAL MARGIN
CONTINENTAL SHELF
CONTINENTAL SLOPE
ECOSYSTEMS
ELEMENTS
EXCRETION
FISHES
MINERAL CYCLING
NITROGEN
NONMETALS
PHOSPHORUS
PHYTOPLANKTON
PLANKTON
SEDIMENTS
SURFACE WATERS
UPTAKE
UPWELLING
VERTEBRATES
ZOOPLANKTON