Shellfish beds on Cape Cod's warm south-facing Nantucket and Vineyard Sounds are closed until further notice. The Massachusetts Division of Marine Fisheries found evidence of a toxic algae bloom and shut down the beds to commercial and recreational shellfishing.
Algae exists normally in both fresh and saltwater, but prolonged hot temperatures can cause the plankton to grow out of control. This can cause toxic symptoms in both people, fish and birds, according to the National Oceanic and Atmospheric Administration.
Affected Cape Cod towns are Falmouth, Mashpee, Barnstable, Yarmouth, Dennis, Harwich, Chatham, Orleans, Aquinnah, Chilmark, West Tisbury, Tisbury, Oak Bluffs, Edgartown and Nantucket.
Coincidentally the annual Wellfleet Oyster Festival takes place this weekend. Shellfish beds in Wellfleet, as well as Cape Cod Bay, Pleasant Bay and Town Cove are unaffected by the emergency order.