Hatcheries:
Irecently explored the benefits that North America’s shellfish aquaculture industry has accrued from their community centred and funded restoration work, and this has led me to think more about what needs to come first for the growth of shellfish aquaculture, the hatchery or the grow-out.
The eastern seaboard of the USA has a long history of restorationIconservation. On Cape Cod many of the small towns have their own shellfish constables who police the shellfish resources, and part of their annual activities are to run seasonal hatcheries for restocking the shellfish public beds.
Hatcheries can be funded by local municipalities as is the case in one shellfish hatchery I visited in October in Martha’s Vineyard.
It is very small yet their annual production for last year was 30 million eyed oyster larvae, 10 million quahogs at 1mm siYe and 20 million scallop set.
These were all for putting in the public beds to enhance the population, which can then be harvested by the local people (under licence).
The hatchery can still apply for and obtain other funds but their long-term survival is underwritten by the municipalities and it has been operating there since 1976.
Its existence has meant potential farmers on the island have been able to obtain initial seed for start-up businesses.
On the Chesapeake Bay there has been a catastrophic loss in oyster harvests over the last century, partly caused by overfishing but also due to significant disease problems with Dermo and MSX.
That is not so different from our own scenario in the UK, where harvests of our native oyster have been devastated by overfishing and disease, in our case, bonamiasis.
The US response to their problem has been geared towards restoration and led to the establishment of an oyster breeding programme in 1997. This was from an initiative of the Virginia General Assembly wanting to address the problem of the diseases by breeding lines of oysters that would be resistant.
The Aquaculture Genetics and Breeding Technology Centre (ABC) led by Stan Allen is now the largest breeding programme for oysters in the US and one of the largest in the world.
They succeeded in producing lines that could thrive in the presence of the disease – three lines to suit the different salinity regimes found within the Chesapeake Bay - and this was done with the aim of restoring stocks and helping the oyster fishery.
But in the process, they have also produced faster growing oysters that make aquaculture more attractive, such that now Virginia is the largest producer of farmed oysters in the US.
ABC can supply the disease resistant brood stock and have also produced triploid and tetraploid oysters for the aquaculture industry. Producing improved genetic lines takes years of patient work and having public funds would seem to be essential.
The restoration itself has also provided benefits in terms of the ecosystem services in the Chesapeake Bay that come with restored oyster reefs.