Invasive Species: North Pacific Seastar

Asterias amurensis, also known as the Japanese starfish

 The North Pacific seastar is another invasive on the list of 100 World's Worst Invasives at #21.

This rather striking Echinoderm is native to much of the Western North Pacific. It is now an invasive off of the coast of South-Eastern Australia. There is no real known use of the species for humans, though it has been suggested that drying for collectibles could be a possibility. In their native range, there are several known predators, including the king crab, but no such predators are seen in its invasive range.

There are numerous ways in which larvae and adults of this seastar can be transmitted to new waters, including in the transport of live fish, ballast water, and they can also attach to the hulls of boats and to equipment. Normally, the larvae are only passed along through normal water currents. Their diet is wide-ranging and can include countless other species, as well as other members of its own species when necessary. This is the cause of the majority of its negative impacts, both in its native range and its introduced range. They also like to feed off of mariculture (i.e. farming of ocean life), which is a great burden on the industry.

There isn't much information on management methods for this species, however studies have shown that this species has the potential to become a major invasive species in the future due to the potential damage they can cause to an area.

Image is from Wikimedia Commons and is copyright free.