Patterns of metal accumulation in Laminaria longicruris from Long Island Sound (Connecticut).

Laminaria longicruris de la Pyl. samples were harvested from Long Island Sound (Connecticut) from January 1985 to January 1986. Cadmium and copper content was determined by atomic absorption spectrophotometry from four tissue types; young blade, old blade, young stipe and old stipe. The results were statistically analyzed for differences in both type and age of tissue. Concentrations of cadmium were consistently lower than copper concentrations for all months and all tissue types. Statistically significant differences (p greater than 0.05) were found between the four tissue types for copper in the months of March, June, July, October and December, and for cadmium in the months of February, March, June, July, October and November. Young blade tissue and young stipe tissue were the tissues which most frequently found to be statistically different from the other tissues. Young stipe tissue had the lowest trace metal concentrations (1.3 mean ppm, dry wt. Cu, 0.22 mean ppm, dry wt. Cd). Young blade tissue had significantly higher metal values in comparison to the other tissues for the months of June and October. Old tissue of L. longicruris is the most suitable for use in biomonitoring of trace metals due to the relatively little variation in metal content that was found throughout the study period.