Photophysiology and cellular composition of sea ice algae

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:5526920

Lizotte, M P

The productivity of sea ice algae depends on their physiological capabilities and the environmental conditions within various microhabitats. Pack ice is the dominant form of sea ice, but the photosynthetic activity of associated algae has rarely been studied. Biomass and photosynthetic rates of ice algae of the Weddell-Scotia Sea were investigated during autumn and winter, the period when ice cover grows from its minimum to maximum. Biomass-specific photosynthetic rates typically ranged from 0.3 to 3.0 {mu}g C {center dot} {mu}g chl{sup {minus}1} {center dot} h{sup {minus}1} higher than land-fast ice algae but similar to Antarctic phytoplankton. Primary production in the pack ice during winter may be minor compared to annual phytoplankton production, but could represent a vital seasonal contribution to the Antarctic ecosystem. Nutrient supply may limit the productivity of ice algae. In McMurdo Sound, congelation ice algae appeared to be more nutrient deficient than underlying platelet ice algae based on: lower nitrogen:carbon, chlorophyll:carbon, and protein:carbohydrate; and {sup 14}C-photosynthate distribution to proteins and phospholipids was lower, while distribution to polysaccharides and neutral lipids was higher. Depletion of nitrate led to decreased nitrogen:carbon, chlorophyll:carbon, protein:carbohydrate, and {sup 14}C-photosynthate to proteins. Studied were conducted during the spring bloom; therefore, nutrient limitation may only apply to dense ice algal communities. Growth limiting conditions may be alleviated when algae are released into seawater during the seasonal recession of the ice cover. To continue growth, algae must adapt to the variable light field encountered in a mixed water column. Photoadaptation was studied in surface ice communities and in bottom ice communities.

• Research Organization: University of Southern California, Los Angeles, CA (USA)
• OSTI ID: 5526920
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALGAE
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
CHLOROPHYLL
GROWTH
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
ICE
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
NITRATES
NITROGEN COMPOUNDS
NUTRIENTS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PHYTOCHROMES
PIGMENTS
PLANTS
PORPHYRINS
PRODUCTIVITY
PROTEINS
SEAS
SEASONAL VARIATIONS
SURFACE WATERS
SYNTHESIS
TRACER TECHNIQUES
VARIATIONS