Optimizing hatchery-based sea scallop settlement

Description

During the life cycle of bivalves, the pelagic larval stages end with progression to benthic life via settlement and metamorphosis. Settlement is a significant limiting factor in the success of pectinid hatcheries. Although in some larval cultures, settlement success rates can reach up to 80% in good conditions, larval settlement and metamorphosis success rarely exceed 25 to 30%. Metamorphosis in bivalves is accompanied by the loss of their larval food collection system (velum) and the development of gills. This period is critical given larvae's limited ability to feed while undergoing metamorphosis. For metamorphosis to be successful, this change must be completed rapidly. Competent larvae will settle and undergo metamorphosis under the influence of various chemical, physical and biological signals that are still unknown for sea scallops. A project funded by the Government of Norway was undertaken in 2007 to identify signals that help to increase settlement and metamorphosis success in P. maximus. The results show the differences in the length of the settlement process, which can vary from one to four weeks depending on the size of the competent larvae. A shorter settlement duration favours faster growth of juveniles and represents an economic benefit for commercial hatcheries. The primary objective of this project is to increase settlement/metamorphosis success while reducing the time required to complete it. The ultimate objective is to establish a settlement rate of over 60%. To meet these objectives, the following combinations will be tested: Effect of size before transfer in the settlement system, effect of velocity and hydrodynamic conditions in settlement units and interaction between size and hydrodynamics.

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)

Year(s)

2010 - 2012

Ecoregion(s)

Atlantic: Gulf of St. Lawrence, St. Lawrence Estuary

Principal Investigator(s)

Jean-Marie Sévigny
Email: Jean-Marie.Sevigny@dfo-mpo.gc.ca