Researchers plan attack on fish-threatening 'rock vomit' organisms

Daily Mail: Sludge report: Researchers plan attack on fish-threatening 'rock vomit' organisms
It’s not the kindest nickname for a sea squirt. But, then again, they are rather invasive organisms.

Alaska researchers are planning a strategy on how to attack ‘rock vomit’, which spreads over hard surfaces such as piers, ship hulls and rocks - and is causing problems to the fish industry worldwide.

The state’s first discovery of the sea squirt was in Whiting Harbour near Sitka last June and it can be lethal to other creatures, including commercially important fish.

If allowed to spread it could pose a serious threat to Alaska’s mariculture business of farming fish and aquatic plants, which is valued at around $500,000 per year.

‘It’s a crazy organism,’ National Oceanic and Atmospheric Administration (NOAA) biologist Linda Shaw said of the light brown mass, scientifically known as Didemnum Vexillum.

‘It smothers other creatures while producing acidic toxins that in turn prevent anything from growing on it.

‘Rock vomit creates a type of barrier between groundfish and their food. It’s been causing problems worldwide.’

The NOAA and state officials will launch an attack campaign on the species after the review.

Maine was the first state to detect rock vomit in 1993 and it is believed to have been introduced by ships dumping their water ballast, reported MSNBC.

The species has since spread to other parts of New England and there are other infestations on the U.S. West Coast in California, Oregon and Washington states.