Florida Department of Environmental Protection

November 03, 2016

CONTACT: DEP Press Office, 850.245.2112, DEPNews@dep.state.fl.us


Charlotte Harbor Aquatic Preserves Staff on the Hunt for Green Mussels


Report sightings of this exotic species to help preserve natural aquatic life and vegetation


PUNTA GORDA, Fla. – Florida Department of Environmental Protection staff at Charlotte Harbor Aquatic Preserves have reported a distinct increase in the presence and distribution of exotic green mussels and are asking the community to report sightings. 

Green mussels are native to the Pacific Ocean, not to Florida. They were first reported in Tampa Bay in the 1990s, when a mat of mussels fouled water intake filters at a power plant, causing it to shut down temporarily. Since then, the mussels have spread around the state. Mussels can be found on dock pilings, navigational markers, rock piles and jetties, and often foul boat bottoms. They are sometimes covered in barnacles, but their tell-tale bright green outer edge usually remains visible.

“We have observed green mussels over the past few years while doing other monitoring, but this year we have seen at least 50 mussels, which has caught our attention,” said Melynda Brown, Charlotte Harbor Aquatic Preserves manager. “We have a large area and can’t possibly survey every hiding place, so any sightings people can report are appreciated.”

Brown’s staff routinely conducts water-quality and sea grass surveys in the bays around Charlotte Harbor. When green mussels are observed, their locations are recorded, along with the depth at which they were found and water-quality conditions at the site. Staff also take measurements of each mussel before manually removing them.

“Green mussels can, at times, compete with barnacles for space, and probably oysters and other native species,” said Steve Geiger, a research scientist with Florida Fish & Wildlife Research Institute. “In the past, the presence of green mussels in Tampa Bay and Sarasota Bay proved problematic because they can form dense mats very quickly.”  

Staff removed 30 mussels during their surveys this summer, and are planning to return to the observed locations to remove any others. Staff have also reported finding mussels in new locations this year, including Pine Island Sound, Cape Haze, Gasparilla Sound-Charlotte Harbor, and near the passes to the Gulf. To supplement ongoing staff efforts, the public is encouraged to report sightings so that aquatic preserves staff can record the information and work to remove the additional reported mussels.

To report sightings, call 941-575-5861 or contact the Charlotte Harbor Aquatic Preserves on Facebook.