Periodic, unpredictable spikes in mortality of commercial oyster crops in spring and summer are a longstanding problem in the industry. While the causes of many of these events are clear (steep changes in salinity, disease, heat waves, etc.), there appears to be an increasing number of high mortality events that occur suddenly (over a matter of weeks) in the spring/summer that are unusual (mortalities of 70% or more in a crop) and, critically, unexplained by obvious causes.
A working group that met at the Virginia Institute of Marine Science (VIMS) in 2024 has deemed this Sudden Unusual Mortality Syndrome, or SUMS. One of the recommendations that came out of this meeting was to improve monitoring of where and when SUMS events were occurring and where they weren’t, see final workshop report here.
An effort led by Dr. Bill Walton at VIMS was launched this year with a short survey (average time to complete the weekly survey is 32 seconds!) that oyster farmers get every Thursday to indicate their level of concern about any mortalities observed in their crop over the past week: green means everything is typical, yellow means something has them paying closer attention, and red means there’s a big problem. Responses are confidential and reporting only occurs for areas with at least three reports in any given week.
To date, 50 responses have been charted from around the US weekly for over 16 weeks. These are posted on Instagram every Monday (@doctor_oyster) and available upon request (see below). If interested, you can sign up at https://tinyurl.com/sumsindex and you’ll get a weekly text or email with a simple stoplight survey to complete.
