Interactions between arsenic species and marine algae

Technical Report · Sun Jan 01 04:00:00 EST 1978

DOI:https://doi.org/10.2172/5875271· OSTI ID:5875271

Sanders, J. G.

The arsenic concentration and speciation of marine algae varies widely, from 0.4 to 23 ng.mg/sup -1/, with significant differences in both total arsenic content and arsenic speciation occurring between algal classes. The Phaeophyceae contain more arsenic than other algal classes, and a greater proportion of the arsenic is organic. The concentration of inorganic arsenic is fairly constant in macro-algae, and may indicate a maximum level, with the excess being reduced and methylated. Phytoplankton take up As(V) readily, and incorporate a small percentage of it into the cell. The majority of the As(V) is reduced, methylated, and released to the surrounding media. The arsenic speciation in phytoplankton and Valonia also changes when As(V) is added to cultures. Arsenate and phosphate compete for uptake by algal cells. Arsenate inhibits primary production at concentrations as low as 5 ..mu..g.1/sup -1/ when the phosphate concentration is low. The inhibition is competitive. A phosphate enrichment of > 0.3 ..mu..M alleviates this inhibition; however, the As(V) stress causes an increase in the cell's phosphorus requirement. Arsenite is also toxic to phytoplankton at similar concentrations. Methylated arsenic species did not affect cell productivity, even at concentrations of 25 ..mu..g.1/sup -1/. Thus, the methylation of As(V) by the cell produces a stable, non-reactive compound which is nontoxic. The uptake and subsequent reduction and methylation of As(V) is a significant factor in determining the arsenic biogeochemistry of productive systems, and also the effect that the arsenic may have on algal productivity. Therefore, the role of marine algae in determining the arsenic speciation of marine systems cannot be ignored. (ERB)

• Research Organization: North Carolina Univ., Chapel Hill (USA)
• DOE Contract Number: EY-76-S-09-0890
• OSTI ID: 5875271
• Report Number(s): SRO-0890-T1
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALGAE
AQUATIC ECOSYSTEMS
AQUATIC ORGANISMS
ARSENIC
BIOGEOCHEMISTRY
BIOLOGICAL ACCUMULATION
CHEMICAL REACTIONS
CHEMISTRY
DATA
DATA FORMS
ECOSYSTEMS
ELEMENTS
EXPERIMENTAL DATA
GEOCHEMISTRY
HYDROGEN COMPOUNDS
INFORMATION
ISOLATED VALUES
METABOLISM
METHYLATION
NUMERICAL DATA
OXYGEN COMPOUNDS
PHYTOPLANKTON
PLANKTON
PLANTS
POLLUTION
PRODUCTIVITY
REDUCTION
SEAWATER
SEMIMETALS
TOXICITY
WATER
WATER POLLUTION