SEDL / STP / STP988-EB / STP26256S

A Rapid Bioassay Using the Green Alga Selenastrum capricornutum to Screen for Toxicity in St. Lawrence River Sediment Elutriates

Ross, P
Associate aquatic toxicologist, Illinois Natural History Survey, Champaign, Il

Jarry, V
Agent de recherche, Université de Montréal, Montréal, Québec

Sloterdijk, H
Survey scientist, Inland Waters Directorate, Environment Canada, Longueuil, Québec

Pages: 6    Published: Jan 1988

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Abstract

A toxicity bioassay using the green alga Selenastrum capricornutum and measuring inhibition of photosynthetic carbon-14 (¹⁴C)-labeled carbon dioxide (¹⁴CO²) assimilation is described. The essential test specifications are the following:

(a) experimental vessels: 16-mL test tubes;

(b) exposure and incubation times: 20 h exposure plus 4 h incubation;

(c) dilution water: demineralized H²O;

(d) algal cell density: 1.9 × 10⁵ cells mL⁻¹;

(e) radioactivity: 0.072 µCi mL⁻¹, as ¹⁴C-labeled sodium bicarbonate [Na²(H¹⁴CO³)²];

(f) nutrient enrichment: 1 mL of × 10 provisional algal assay procedure (PAAP) medium; and

(g) isotope partitioning: acidification and bubbling.

The resulting method is rapid, sensitive, and reliable (coefficient of variation < 10%) and is applied to elutriates of St. Lawrence River sediments in an ongoing research project.