Copepods link quahog growth to climate

From samples collected in 1983, 1991 and 2000, a long-term growth record for the bivalve Arctica islandica from the northern North Sea was constructed with methods derived from dendrochronology. Subsequent response-function analyses demonstrated that shell growth was mainly influenced by the abundance of copepods as recorded by the CPR survey. In years with dense copepod populations a major part of the downward flux of food particles is intercepted by the copepods before it reaches the seafloor. This may lead to a shortage of food for A. islandica resulting in a depression of shell growth. Although the abundance of copepods in the northern North Sea is linked to climate there is only a weak statistical relation between shell growth and climate.