Factors Influencing the Distribution of the Bivalve Macoma Balthica of the Intertidal Mudflats of Cobequid Bay, Nova Scotia

Abstract

<p>Population studies on the bivalve Macoma balthica L. in the intertidal mudflats of Cobequid Bay, Nova Scotia show some of the highest recorded densities; maximum density was 3492/m2. Direct bacterial counts of 40 surface sediment samples gave an average bacterial density of 5.9 X 10^9 bacteria/g. dry wt. sediment. Macoma densities correlate significantly with bacterial densities (r = .880). The organic carbon contributed by the bacteria represented an average of one-third of the organic carbon in the sediment; organic carbon was found at an average of .4% by weight in the sediment. Calculations of daily protein requirements of Macoma balthica show that there is insufficient protein present in the sediment. The bivalve probably filter feeds to supplement its diet. No correlation was found between Macoma densities and either organic carbon distribution or vertical position on the mudflat.</p>