Shellfish Culture – American Oyster (Crassostrea virginica) *¹  

We find around 55-60 business that culture the American oyster in New Brunswick;

We count 534 active sites (area: 3,020 hectares);

We count 523 sites licensed for the culture of American oyster (area: 2664 hectares);

We count 324 sites for bottom culture only (area: 1,253 hectares);

We count 210 sites allowed for suspension or off bottom culture (area: 1,767 hectares);

Live stock is estimated at ±120 million units of different year class;

Farm gate price is from 0.28 $ to 0.38 $ per unit;

Sale is evaluated of 11 million units, including cocktail oysters (63 mm) and commercial oysters (76 mm and more). 

Biology – American Oyster (Crassostrea virginica)*²

In the Maritimes, good oyster bottom is found in the lower portion of the intertidal zone and in subtidal areas down to water depths of 5-8 m;

An adult oyster can circulate up to 34 l of water per hour; 

The average oxygen consumption of healthy adult oysters ranges between 3.0 and 5.3 mg per oyster per hour; 

American oysters often reach sexual maturity at a shell length of 2.5 cm; 

The average female can produce up to 70 million eggs per year, and males even greater numbers of sperms; 

In the Maritimes oysters with ripe gonads will spawn if the water temperature rises above 20^oC; 

In our latitude, oysters spawn intermittently over a period of up to six weeks; 

Eggs measure from 55-75 µm, straight-hinge larvae 70-75 µm, and umboed larvae 300 µm; 

Oyster larvae reach maturity at sizes ranging from 280-370 µm; 

Their mean size at fixation is 340 µm; 

The production cycle is reached in 3 to 5 years.

Shellfish Culture – Blue Mussel (Mytilus edulis) *¹

We found 2 main businesses that culture blue mussels in New Brunswick;

We count 29 sites licensed for the culture of blue mussel (area: 664 hectares);

The production is stable since 2000, i.e., ± 500 metric tons;

Farm gate price is from 0.50 $ to 0.60 $ per lbs.

Biologie – Moule bleue (Mytilus edulis) *³

A substantial volume of water is moved through the mussel by the beating of the lateral cilia on the gills – up to 100 l per day for a 60-mm mussel;

A rise in temperature above 10^oC to 12^oC is generally thought to be essential for mussels to spawn; 

During a single spawning, a large female can release up to 20 millions eggs (0.065 mm in diameter), which may constitute up to 50 percent of its body weight; 

Two-year-old mussels in the Magdalen Islands were observed to lose 32 percent of their body weight by the release of 3 to 4 million eggs; 

When the larvae reach a shell length of ~250 µm to 300 µm, they develop a foot, which they use to locate a suitable settlement substrate; 

Juvenile mussels less than 2 mm can easily detach themselves from the substrate and change locations; 

Mussels can tolerate a wide range of salinities, varying from 0 ‰ to 31 ‰, although shell growth is severely reduced at salinities below 13 ‰ and under widely fluctuating salinity conditions; 

Acceptable growth rates are recorded at salinities above 18 ‰, with an optimum at 26 ‰; 

In Atlantic Canada, cultured mussels are often exposed to temperatures ranging from -2^oC to more than 25^oC; 

Temperatures higher than 28^oC are known to cause mass mortality in wild mussel populations.

*¹ data 2007

*² informations from Lavoie, R. E. (1995). Culture of the American oyster, Crassostrea virginica.  In A. Boghen (Éd.), Cold-water aquaculture in Atlantic Canada. (p. 189-224). Moncton, NB: The Canadian Institute for Research on Regional Development.

*³ informations from Mallet, A. et B. Myrand (1995). The culture of the Blue Mussel in Atlantic Canada. In A. Boghen (Éd.), Cold-water aquaculture in Atlantic Canada. (p. 254-296). Moncton, NB: The Canadian Institute for Research on Regional Development.