University of Florida

What are Green Mussels?

Green mussels (also known as Perna Viridis) are non-native bivalve mollusks which have recently invaded the coastal marine waters of Florida, USA. Evidence for the presence of this invasive species has been found on both the Gulf coast, from the panhandle to Naples, and the northern and north-central portion of the Atlantic coast.

Invasive Green Mussels

This cluster of green mussels was found growing on a derelict crab trap pulled from Tampa Bay in January, 2009. (Florida Sea Grant Photo) Click on image to enlarge.

The Problem With Green Mussels

Like other mussels, green mussels attach to hard surfaces with tough byssal threads, and can form dense layers. In Florida, green mussels have already caused problems for some coastal industries. These dense assemblages of mussels can be costly problems when they clog seawater intakes, weigh down navigation buoys and foul the hulls and engines of boats. Green mussels can also have serious effects on Florida's native fauna. In Tampa Bay, some native oyster reefs have died off after being smothered by green mussels.

The Future of Green Mussels

Fortunately for most of the United States, green mussels are tropical mollusks and are killed by cold weather. Even in Tampa Bay, Florida, green mussels have experienced cold-related die-offs. They may not spread much further north than they already have, although global warming may expand their potential habitat. It is too early to say whether green mussels are safe to harvest for human consumption, and we recommend against it until further information is available. They are edible in their native range, but in Florida, green mussels mostly grow in waters that are either polluted or prone to harmful algal blooms.

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