Population Dynamics of the Clam, Chamelea gallina, in the Adriatic Sea (Italy)

In the western Adriatic Sea the fishery for the clam, Chamelea gallina, by means of hydraulic dredgers is by far the most important bivalve fishery, having reached landings of over 100000 t in the early 1980s. Owing to this intense fishery, the clam population has undergone profound modifications and substantial reductions in biomass throughout the years. Thus, between 1984 and 2001 the scientific community was given the task of annually assessing the state of this resource. This paper is aimed at presenting the results obtained from the surveys carried out in the Ancona (AN) and S. Benedetto (SB) Maritime Districts between 1984 and 2001. The results are indicative of a resource and a fleet heavily dependent on stochastic substantial recruitment events. A stressed resource was revealed which was unable to cope with the intense exploitation. Large recruitment events followed by significant natural mortality episodes and the paucity of older individuals may suggest a shift in the allocation of energy, from growth to reproduction. Following the collapse of the resource in 2001, in SB especially, part of the vessels were redistributed in the nearby AN district. This caused a considerable increase in fishing effort and a further depletion of the resource as highlighted by the long closure periods. Despite this no further surveys were funded. Its is our hope that this contribution may, somehow, act as a catalyst for the resumption of the assessment of a crucial coastal resource