Factors influencing the survival and growth rate of Mercenaria mercenaria

Samenvatting

Shellfish are a healthy source of protein but more strict regulation for traditional shellfish fisheries and fluctuations in population size warrant a need for sustainable and more reliable alternatives. These alternatives can be, for example, the culturing of new species like hard clam (Mercenaria mercenaria). Recent experimental efforts in Zeeland have demonstrated significant potential in farming hard clams, offering a robust, adaptable species for aquaculture development in the Netherlands. In the project “Alternatieve perceelgebonden schelpdierkweek”, funded by RVO (subsidy SDVA), Stichting zeeschelp, Meromar Zeeland and HZ University of Applied Sciences (HZ) aim to develop a concept for sustainable aquaculture of M. mercenaria that encompass the whole production cycle; from the conditioning of the adult clams to the harvest and processing of the clams. The developed concept should serve as a viable alternative to existing bivalve aquaculture and fishing. This initiative is part of a broader effort to diversify and innovate within the fisheries and aquaculture sectors. As part of this project the HZ executed a literature study on the first step in the production cycle: the production of viable larvae from broodstock in a hatchery and subsequent settlement. These phases within the production cycle are particularly sensitive and should be given more attention. The aim was come to an optimal hatchery set up. The results of this literature study on factors that influence growth, survival and settlement success of hard clam larvae are the main focus of this report. In addition to this an experiment was designed to investigating the best diet for rearing juvenile hard clams based on the outcome of the literature study. However, the experiment was never executed due to failing settlement of the hard clams. The experimental set-up as well as the results of the pre-test executed, are included in this report (Annex I & II). Also include is an innovative method to measure growth of juvenile clams using Calcein staining (Annex III)