Snakefish (left), Lion fish (right)

Two recent articles about alien invasive species: The New York Times reports on efforts to stop the smuggling of the Chinese snakehead fish. The fish is considered to be  a delicacy in New York’s Chinatown, but is a voracious predator that can wipe out entire schools of fish and destroy an ecosystem when released outside of its natural habitat.   Likewise the BBC reports on  the ‘Godzilla’ lionfish and its threat to Caribbean waters, where it has no natural predators.

A Delicacy on Chinatown Plates, but a Killer in Water

In China, the snakehead is a sweet, meaty staple harvested in farms, and when boiled into soup, it is reputed to possess remarkable healing properties. But once outside of its natural river habitats in China, Korea and Russia, it is a rapidly reproducing predator with such a voracious appetite it can wipe out entire schools of fish and destroy an ecosystem.

That the snakehead has been illegal to import into the United States since 2002 when it was found in a pond in Maryland has not diminished its demand — and perhaps has only fueled it. The fish, which has also been illegal to possess in New York State, has been sold in other markets like Boston and is also available through the Internet, officials with the United States Fish and Wildlife Service said.

‘Godzilla’ lionfish threatening Cayman paradise

An explosion in the population of the predatory lionfish in Caribbean waters, where it has no natural predators, is posing a widespread threat to marine wildlife.

The facts about lionfish are frightening.  Lionfish have red-brown stripes and long venomous spikes.  A female can produce 30,000 eggs every four days. The eggs are unpalatable to other fish.  And lionfish are growing larger than they do in their native waters – up to 18in long (47cm), and they are stealthy ambush predators.

No-one knows how lionfish got into the Caribbean.

One theory says they escaped from a Florida aquarium during a hurricane about 10 years ago.

Others believe that tropical fish keepers released their pets into the sea when they grew too large to keep at home.

One study in the Bahamas showed that lionfish reduced native species populations on one reef by almost 80%

It does not really matter how they got here, but since 1992 they have spread from Florida up the east coast of the United States as far north as Long Island in New York.