Low specific nitrate uptake rate: A common feature of high-nutrient, low-chlorophyll marine ecosystems
- Univ. of Southern California, Los Angeles (United States)
The authors have searched for common features of three high-nutrient, low-chlorophyll (HNLC) regions of interest - the Southern Ocean, the eastern equatorial Pacific, and Station P in the northeast Pacific. In each of these areas, the rates of specific NO{sub 3} uptake, whether normalized to particulate organic nitrogen (PON) or chlorophyll, are low compared to coastal upwelling systems with comparable nutrient concentrations. When maximum values of NO{sub 3} concentration and maximum values of PON-specific {sup 15}NO{sub 3} uptake, V{sup 15}NO{sub 3} track for the coastal systems, and a low V{sup 15}NO{sub 3} track for the three HNLC regions which have V{sup 15}NO{sub 3} values consistent with oligotrophic regions and so are functionally oligotrophic. These values of V{sup 15}NO{sub 3} are too low to allow biomass accumulation and the formation of blooms of diatoms. One possible reason for the lack of high V{sup 15}NO{sub 3} values in the HNLC regions is that seeding of the large, fast-growing, fast-sinking diatoms is inadequate and primarily due to the lack of a bottom or other recirculation system to assure a supply of these diatoms to the surface regions. Grazing control limits biomass development and may function to hold V{sup 15}NO{sub 3} to low values resulting in conditions certain to appear as HNLC. Comparison with model results suggests that deep mixed layers in the Southern Ocean and at Station P may limit V{sup 15}NO{sub 3} and that in much of the eastern equatorial Pacific NO{sub 3} concentrations are too low for VNO{sub 3} to develop to coastal upwelling values.
- OSTI ID:
- 7250608
- Journal Information:
- Limnology and Oceanography; (United States), Vol. 36:8; ISSN 0024-3590
- Country of Publication:
- United States
- Language:
- English
Similar Records
Miocene-Early Pliocene diatomaceous sedimentation patterns in the Pacific: A response to paleooceanography and paleoclimatic change
Oceanic upwelling and productivity in the eastern tropical Pacific
Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
29 ENERGY PLANNING
POLICY AND ECONOMY
ANTARCTIC OCEAN
BIOGEOCHEMISTRY
NITRATES
UPTAKE
PACIFIC OCEAN
PHYTOPLANKTON
ECOLOGICAL CONCENTRATION
PRODUCTIVITY
AQUATIC ECOSYSTEMS
CHLOROPHYLL
NITROGEN 15
NUTRIENTS
OCEANIC CIRCULATION
TRACER TECHNIQUES
UPWELLING
AQUATIC ORGANISMS
CARBOXYLIC ACIDS
CHEMISTRY
ECOSYSTEMS
GEOCHEMISTRY
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
NITROGEN COMPOUNDS
NITROGEN ISOTOPES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
PHYTOCHROMES
PIGMENTS
PLANKTON
PLANTS
PORPHYRINS
PROTEINS
SEAS
STABLE ISOTOPES
SURFACE WATERS
540320* - Environment
Aquatic- Chemicals Monitoring & Transport- (1990-)
560300 - Chemicals Metabolism & Toxicology
290301 - Energy Planning & Policy- Environment
Health
& Safety- Regional & Global Environmental Aspects- (1992-)