Someone came into the office today and asked me, “How are the oysters Charlie?” Sadly, I didn’t have a simple answer for them. Back in 2002 it was confirmed that MSX, an oyster parasite, was detected in some key oyster-producing areas of the Bras d’Or Lakes. At first, small mortalities were reported and questions arose as to how much of the Bras d’Or Lakes was infected. Again, not an easy question to answer. So UINR partnered with Eskasoni Fish and Wildlife Commission (EFWC), Fisheries and Oceans Canada (DFO), Nova Scotia Fisheries and Aquaculture and the National Research Council-Industrial Research Assistance Program to find some answers.
We learned that MSX originated in the United States in Delaware and Chesapeake Bays in the 1950s. Research included assessing areas affected by MSX, researching the biology of the parasite, trying to determine the origin of the infected oysters, determining if other shellfish would carry MSX if they were moved around and identifying how we could work around the problem.
UINR and EFWC have taken part in most, if not all, of the MSX projects in the Bras d’Or Lakes and spearheaded the “Initiation of a breeding strategy for an MSX tolerant oyster.” Some of the children of the oysters that were used in this hatchery work are growing in the Bras d’Or Lakes now. Sadly, there is not a lot of funding for these types of projects and little work is being now being done.
Today the oyster in some parts of the Bras d’Or Lakes is doing fine. Each summer we see spat on eel grass in areas like Denys Basin which means there are larger oysters around. Mothers and fathers produce young despite oyster diseases like MSX and Malpeque (a disease that I have not touched on today). Other areas of the Bras d’Or Lakes are not so lucky. Beds that were once an oyster fisher’s salvation are no longer producing. Is this because of disease, over-fishing, pollution or loss of habitat? At times it’s hard to tell. We do know that the oyster in the Bras d’Or Lakes is not as plentiful as it once was. It is no longer able to feed the Mi’kmaq as it once did. This is a shame.
There are still areas, like the waters near Potlotek, where MSX is found but not causing problems… yet. DFO has precautions in place so that it is not spread by humans. This includes cleaning boats between launching sites (spraying with an iodine solution is the best method) and fishing from least infected to most infected areas so as not to spread MSX through oyster fishing activities.
Instead of asking, “How are the oysters?”, perhaps we should be asking, “How are the humans?” How are humans going to survive without the oyster as a source of food? How are humans going to survive without the oyster filtering the waters of our swimming and fishing areas? In the end, I believe the oyster will survive and thrive once again. In our lifetime? Only time will tell.