An energy budget for a Macoma balthica (mollusca) population living on a tidal flat in the Dutch Wadden Sea

Abstract

Seasonal and annual energy budgets were compiled for individuals and for a tidal flat population of Macoma balthica in the western part of the Dutch Wadden Sea, based on independent estimates of their numbers, biomass, food consumption and absorption, production and respiration. The consumption of food reached a maximum in late winter and remained high during spring. The absorption of food was maximal in spring and minimal in autumn and early winter. The absorption of food related to chlorophyll a was high only during April, May and June. The respiration was high during spring and summer and reached a minimum in winter. Somatic growth and gonad output were high only in the months April, May and June, whereas weight. Indeed, estimates for the absorption of chlorophyll a related food minus respiration were only high during the three months. The production of Macoma appears to depend primarily on the concentration of chlorophyll a related food in the water. The maintenance ration on basis of total consumption amounted to 1.3% of the body weight per day or, when based on the absorbed chlorophyll a related food to 0.4%. The net growth efficiency was 19% on the basis of all absorbed food, and 28% on the basis of chlorophyll a related food.