Balanus amphitrite is a common, broadly distributed coastal and estuarine biofouling organism found on hard natural surfaces such as rocks, in oyster beds, red mangrove (Rhizophora mangle) prop roots and mollusc shells. It is also found on artificial substrates like ship hulls, pilings, riprap, and seawalls.The native range of B. amphitrite is uncertain, but may be located in the Indian Ocean to the southwestern Pacific, based on its presence in the Pleistocene fossil record (Cohen 2005). It is now a dominant fouling organism found in warm and temperate waters worldwide (Desai et al. 2006).USGS collection information lists B. amphitrite as established in Florida coastal waters by 1975 (Henry and McLaughlin 1975, Carlton and Ruckelshaus 1997), but the initial introduction most likely occurred much earlier and the first reports of the species in Florida date to at least the 1940s. Mook (1983) reported Balanus amphitrite and B. trigonus as occurring in lesser abundances than B. eburneus is India River Lagoon settlement studies conducted in 1977-1978 in Fort Pierce in the vicinity of Harbor Branch Oceanographic. Boudreaux and Walters (2005) suggest B. amphitrite and the native B. eburneus are abundant in the Mosquito Lagoon portion of the estuary.