Possible impacts of ozone depletion on trophic interactions and biogenic vertical carbon flux in the Southern Ocean

Technical Report · Sun Mar 01 00:00:00 EST 1992

OSTI ID:7264152

Marchant, H J; Davidson, A

Among the most productive region of the Southern Ocean is the marginal ice edge zone that trails the retreating ice edge in spring and early summer. The timing of this near-surface phytoplankton bloom coincides with seasonal stratospheric ozone depletion when UV irradiance is reportedly as high as in mid-summer. Recent investigations indicate that antarctic marine phytoplankton are presently UV stressed. The extent to which increasing UV radiation diminishes the ability of phytoplankton to fix C02 and/or leads to changes in their species composition is equivocal. The colonial stage in the life cycle of the alga Phaeocystis pouchetii is one of the major components of the bloom. The authors have found that this alga produces extracellular products which are strongly UV-B absorbing. When exposed to increasing levels of UV-B radiation, survival of antarctic colonial Phaeocystis was significantly greater than colonies of this species from temperate waters and of the single-celled stage of its life cycle which produces no UV-B-absorbing compounds. Phaeocystis is apparently a minor dietary component of Antarctic krill, Euphausia superba, and its nutritional value to crustacea is reportedly low. Phytoplankton, principally diatoms, together with fecal pellets and molted exoskeletons of grazers contribute most of the particulate carbon flux from the euphotic zone to deep water.

• Research Organization: Alaska Univ., Fairbanks, AK (United States). Geophysical Inst.
• OSTI ID: 7264152
• Report Number(s): AD-P-007315/5/XAB
• Resource Relation: Other Information: This article is from 'Proceedings of the International Conference on the Role of the Polar Regions in Global Change Held in Fairbanks, Alaska on 11-15 June 990. Volume 2', AD-A253 028, p397-400. See also Volume 1, AD-A253 027
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ANTARCTIC OCEAN
CARBON CYCLE
OZONE LAYER
ECOLOGICAL CONCENTRATION
PHYTOPLANKTON
PRODUCTIVITY
ALGAE
CARBON DIOXIDE FIXATION
CLIMATIC CHANGE
ENVIRONMENTAL IMPACTS
ICE
LIFE CYCLE
NUTRIENTS
SEASONAL VARIATIONS
ULTRAVIOLET RADIATION
AQUATIC ORGANISMS
ELECTROMAGNETIC RADIATION
LAYERS
PLANKTON
PLANTS
RADIATIONS
SEAS
SURFACE WATERS
VARIATIONS
540120* - Environment
Atmospheric- Chemicals Monitoring & Transport- (1990-)