Virginia Scientists Probe New Oyster Problem

 Bay Journal, Virginia scientists investigate mass oyster die-offs

The Virginia Institute of Marine Science released a new report in June on the unexplained massive die-offs at oyster farms. The report is from a two-day workshop in January. Over 25 oyster aquaculture experts discussed their latest studies on the Sudden Unusual Mortality Syndrome, or SUMS.

The syndrome was first reported in 2012. It affects farmed oysters during peak reproduction time between May and early July. According to VIMS, the mortality exceeds 70% at aquaculture locations across the Atlantic and Gulf coasts. But no one knows why.

The report ruled out common oyster diseases like Dermo and MSX as the sole or prominent culprit. Instead, researchers theorize that stressors from the environment and aquaculture cultivation methods play a large role.

One theory that emerged from the workshop focused on the oyster genetics. Triploid oysters have three chromosomes and can’t reproduce. Oyster farmers like to raise them because all the bivalves’ energy goes toward growth. So, some researchers from the workshop received a grant to compare how triploid and non-triploid oysters do under multiple stressors.

Researchers at the workshop also explored how salinity, water temperature and the presence of algae during cultivation affected oyster species differently.

In the future, scientists hope to understand these periods of mass deaths and analyze the genetics of oysters that survived. The group also suggested breeding oysters for general resilience instead of resistance to just one stressor.

The group agreed that the aquaculture industry and research community must collaborate and communicate more to solve the problem. They hope to share data on the occurrence of SUMS at oyster farms across the coast, genetic samples and more. They also want to create an emergency response network.

The syndrome does not appear to pose any risk to those buying or consuming oysters.

The triploid theory is interesting, but if triploid oysters have a weakness, why has it taken so long for the problem to emerge? Clearly, there must be something else in play. 

The Wombat has Rule 5 Sunday: Sydney Sweeney IS Black Cat! up and pining for attention at The Other McCain.