Development of a Recirculating Seawater System to Cool Farmed Mussels from Semi-Open Water Held in Live-Wells during their Spawning Period

Summary:
The requirements of the fresh mussel market in Québec oblige conditioning plants to maintain a year-round mollusk production calendar. Consequently, keeping the supply stable throughout the year is a major issue in mussel marketing. The summer period, when it is impossible to keep mussels in conventional live wells and when their physiological condition (spawning) makes it harder to handle the mussels, is the most critical. The characteristics of blue mussels farmed deep (10 m) in semi-open water (Gaspé Peninsula) differ from those of mussels farmed in the Maritimes. In fact, mussels reared in semi-open water experience partial spawning from June to September, which makes it harder to handle them. The ultimate goal being to secure mussel supply during the summer time, this project aims to develop a system of live wells with an integrated seawater cooling mechanism that is suited to the characteristics of mussels farmed in semi-open water.

The system developed through this project is composed of a buffer tank, a refrigeration unit and a heat exchanger, which together serve to cool the seawater. The cold water exiting the tanks is pumped back through the heat exchanger, which recovers the energy before dumping the seawater back into the sea.

The system designed around a 20-HP cooling unit was able to maintain the water at a temperature that was 7°C cooler than the water in the sea at a flow rate of 120 l/min. and a cost of $0.004 to $0.008 per pound of stored raw mussels. The heat exchanger proved to be quite efficient, although efficiency can be limited by the presence of spat if there is no well-established cleaning process.

Recipient: MenuMer Ltée

Total Project Cost: $111,856

DFO-AIMAP Contribution: $57,214.80

Other Financial Support:

• Recipient : MenuMer Ltée
• Industry : Société de développement de l’industrie maricole (in French only) (SODIM)

For more information on this project, please contact the regional coordinator.

Quebec Region: Pierre.Lauzier@dfo-mpo.gc.ca