Deep-Sea Stowaways Could Be Invasive

A team of researchers unwittingly brought up stowaway limpets and mollusks from the California ocean bed that could adversely affect ecosystems not used to them. It is thought that they might already be colonizing in Washington State's waters.

It all started in 2006, when the deep-sea submersible Alvin conducted an expedition to some hydrothermal vents in California. The submersible collected sediment and rock and was then transported to Washington State for another dive two days later. The researchers were shocked to find limpets and mollusks similar to the ones from California in the samples from the Washington State dive.

"This was exciting and surprising at first, but then things stopped adding up," said expedition member Voight, an invertebrate zoologist at the Field Museum of Natural History in Chicago to National Geographic.

After some years of genetic research, the team confirmed that they were indeed the same limpets and the mollusks from California.

There is a chance of danger with both species. This particular species of limpets has evolved to carry bacteria in their gills that could be disease causing. The mollusks can harbor tiny copepods, which feed on limpet gonads.

The habitat where these two species come from makes them extremely adaptable and aggressive. 

Hydrothermal vents are situated on volcanic ridges which spread over time, changing the habitat of these deep-sea vents. In order to cope with an ever changing habitat, the inhabitants, inluding these species of limpets and mollusks, evolve fast and reproduce quickly.

"They're primed to exploit any open habitat. It's kind of a recipe for disaster," explained Voight.

The Alvin's protocol requires that it be flushed down properly before being moved to another site, but it seems that the California dive was the one time the team forgot to do it.

"It's really embarrassing that we did this," Voight said. "We should have known better, but it didn't seem like a clear and present danger."