Asian Green Mussel
The Asian green mussel is native to the south-western Pacific Ocean. It was first identified in 1962 at Sydney Harbour in Australia.
They attach themselves with thread-like byssus filaments to hard surfaces, where they are well camouflaged against predators that cannot enter the shell aperture or prise them from their moorings. They have been reported widely in the Atlantic and Pacific Oceans,
In Hawaii, they have been reported from more than 200 of the islands' harbors and on a number of piers. In Europe, they have been found along more than 1,000 kilometers of coastline within a few years.
They have high growth rates and long-lived planktonic larvae that are widely distributed by currents. The larvae settle preferentially on hard surfaces, where they attach with byssus threads. They form dense populations, up to 35,000 individuals per square meter on a variety of hard marine structures.
The biology of the mussel has been the focus of many studies, with over 10,000 scientific reference articles published on them. They are widespread in distribution due to their fast growth rates, longevity, and lack of known predators outside their native range.
The mussel has long been considered a pest species worldwide but is especially prominent in Hawaii. It was first found there in 1993 and has since reached densities of 30,000 per square meter.
The mussels are completely protected by their shells (1-2 cm thick) and do not feed as adults; they rely on food reserves during larval development. Such high densities result in significant changes to nearshore communities where the mussel is present; there is very little macroalgal growth, few native invertebrates, and low species diversity.
The mussels also provide a habitat for small fish that feed on their mucous and larvae; these in turn are consumed by larger fishes that prey on the small fish populations. On reefs where there has been mussel infestation, sea urchins have multiplied and consumed large amounts of algae.