Ballast Waters Introduce Invasive Species to Tampa Bay

In Tampa Bay the introduction of Asian Green Mussel is competing with native species of Eastern Oysters for prime real estate throughout the Bay Area’s estuaries. Green mussels clog the pipes of power plants and desalinization plants and compete with native species. (Florida Fish and Wildlife Conservation Commission, 2011) Juvenile mussels have been noted to bed in at several thousand individuals per square meter in Tampa Bay. This suggests that the green mussel is a formidable spatial competitor (Power, 2004). Large non-native green mussel populations may also represent a significant source of competition for planktonic food resources. In Tampa Bay, some native eastern oyster reefs have died off after being smothered by green mussels.

When ships leave foreign ports, they take on water into their ballast tanks for stability. They normally will de-ballast water at sea or home ports. Ballast water has been known to contain fish, mollusks and various bacteria and algae species that can crowd or overtake native species. These inductees are called invasive species. In their native habitats they are benign as part of their natural ecosystem. Introduced into a foreign ecosystem, some taxa find their “new home” to be bountiful and without the constraints of their previous niche to keep their population in check.

The native range of the green mussel is along the Indian coast and throughout the Indo-Pacific and Asian Pacific. Green mussels were first observed in the Caribbean in 1990. Within 10 years, green mussels had been found along the coasts of Venezuela and Jamaica and in Tampa Bay, Florida. (University of Florida, 2007) Because the currents are not a factor in the transport, but ship ports are common factors in these countries, that ballast water is the most likely conduit of the green mussel.

While removing the green mussel manually is the only direct solution, preventative measures to keep the species from being re-introduced are the best measure of...