The Asian green mussel (Perna viridis) was found in Tampa Bay in late 1999.
The Asian green mussel (Perna viridis) was first found in Tampa Bay in late 1999. The Asian green mussel is not native to Florida's waters. The Florida Fish and Wildlife Conservation Commission (FWC) is concerned about the presence of this mussel and the effect that it may have on native Tampa Bay species and Tampa Bay's ecosystems. This mussel should also be of concern to boat owners; electric utilities; and anyone who maintains structures such as sea walls, docks, navigational markers, bridges, and intake and discharge structures. As larvae, the green mussel settles on hard, submerged surfaces and can form large masses of mussels. The mussel larvae are capable of swimming, and even in swift currents, they are able to settle onto surfaces. The mussels can restrict water flow in pipes and increase drag on other structures, such as boat hulls. The green mussel, which has a brown, yellow and bright emerald green or blue-green shell, apparently grows rapidly and can exceed six inches (160 mm). The green mussel has become widely distributed in Tampa Bay and Sarasota Bay. This invasive species had spread to Charlotte Harbor by 2000, Ten Thousand Islands and the Mosquito Lagoon by 2002, Jacksonville and Savannah, GA in 2003, and has been reported as far north as Charleston, S.C.
The green mussel is originally from the Indian and Pacific Oceans. It came into the Gulf of Mexico about ten years ago, presumably as larvae in the seawater ballast tanks of a large ship. Scientists suspect that the same method of transportation brought the green mussel to Tampa Bay. In China, the Philippines, and Malaysia the green mussel is highly prized as food. Note: Shellfish, including mussels, from most of Tampa Bay are not safe to eat: Shellfish harvesting in a large part of Tampa Bay is prohibited. There are two areas of Tampa Bay that are considered "conditionally approved." These two areas are usually open but periodically closed to shellfish harvesting based on pollution events, such as rainfall or increased river flow. See maps on the Department of Agriculture and Consumer Services Web site for Boca Ciega Bay and South Tampa Bay for current status.
The FWC wants to prevent green mussels from becoming a nuisance species in other Florida habitats. It is possible for boaters to inadvertently move mussels from Tampa Bay to other waters. The mussel larvae may be in bilge water and adult mussels may be attached to boat hulls.
To help prevent the spread of these mussels, boaters can follow these suggestions:
- Inspect any boat that has been in Tampa Bay unprotected (without fresh bottom paint); remove and dispose of mussels if you see them.
- Prior to transporting boats to other water bodies, drain the bilge at an appropriate disposal station or, if no oil is present in the bilge water, into Tampa Bay.
- Spread the word; make others aware of the problem non-native species can cause in our natural ecosystems.
The Molluscan Fisheries project at the Florida Fish and Wildlife Research Institute will be surveying the distribution of green mussels in Tampa Bay and conducting investigations on the reproductive cycle of the mussels. Research staff members are distributing informational posters to various user groups around Tampa Bay.
The FWC is particularly interested in reports of this mussel from the Panhandle and western Gulf of Mexico as well as southeastern Florida. If you suspect that you have seen green mussels or have questions, please call:
Florida Fish and Wildlife Conservation Commission
Florida Fish and Wildlife Research Institute
Dr. Steve Geiger
For more information about this species or other non-indigenous species:
University of Florida: Green Mussels in Florida
USGS: Establishment of the Green Mussel, Perna viridis