Transsexual eels invade New Jersey

It's too bizarre to be true. Slimy, invading eels that survive drought, and can change sex if needed to reproduce.

It's the invasion of the Asian swamp eels. One more in a series of unwelcome creatures that are replacing native fish because they can.

The Asian swamp eel is a protandrous hermaphrodites. Those are big words that mean

beginning life as males but able to change into females if the need arises.

Wonder what that means, if the need arises?

hat tip: Zooillogix

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Do healthy reefs protect themselves?

The idea that intact trophic structures and diverse ecosystems are more resilient than their depauperate over-extracted kin has been tossed around in scientific circles for many years. The diversity = resilience hypothesis is getting new scrutiny in the oceans today because of the threats of acidification and warming temperatures. Can the seas survive better if they get to keep all their parts (even if we don't understand exactly how they work)?

The August issue of Current Biology has new evidence saying yes. Dr. Hugh Sweatman and many brave associates spent ten years being towed around the Great Barrier reef counting crown-of-thorns starfish. COTs are nasty, poisonous little buggers that swarm in waves, eating corals. Researchers found that areas open to fishing were 3.75 times more likely to have COTs outbreaks than no-take marine reserves in the same area. Adult fish aren't direct predators on the starfish -- since almost nothing can eat a 10" diameter helping of neurotoxins -- but having them around may protect invertebrates that prey on juvenile COTs. Time for more manta tows to figure out the causal mechanism and in the meantime, keep those marine reserves going.

You can get the full paper through the Australian Institute of Marine Science website.

Crown of Thorns photo © Alexey Bogdanov

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Your lionfish don't want to be free

Lionfish get a primetime spotlight tonight on NBC News for their ability to deliver powerful stings and eat their way through Florida's reefs.
According to the article, OSU's Dr. Mark Hixon will be releasing a new paper showing that "one lionfish can deplete 79% of a reef in five weeks."

Let this be a reminder that, like puppies and babies, lionfish are a long-term commitment and you can't just abandon them when you get bored. Florida's grouper thank you.

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Ugly American invader detected with DNA testing

How to find and eradicate the boorish, bullying ugly American invader in sensitive French environs? French scientists used DNA tests to find bullfrogs that threaten more refined French frogs. The DNA testing works where it's hard to find the actual culprit.

Why go to such great lengths to find and hopefully get rid of this ugly American invader? The bullfrog is

"one of the world’s most harmful invasive species, since it is responsible for the decline of natives by direct predation, competition, diffusion of diseases and complex biotic interactions."

This approach is useful since finding invasive species can be difficult, especially when invasions are new and perhaps capable of being reversed. Early detection is important in mounting an early response.

Image: bullfrog (below) green frog (above)

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The bluegill that ate Japan

Or at least ate Japan's fish. The problem is so bad that the Emperor is apologizing for bringing bluegill into Japan in the 1960s.

Chicago mayor Richard Daley gave bluegill, the state fish of Illinois, as a gift to the current Emperor in 1960. Hoping to create a new delectable food source, Japanese fish biologists established the bluegill in lakes. Now, bluegill are eating and depleting some native species, and they've become an official nuisance. "Its cultivation started as there were great expectations of raising them for food in those days. My heart aches to see it has turned out like this," Emperor Akihito said.

To control the bluegill, there is a "catch and eat" policy for bluegill. Who knew that these nice little fish could be such a scourge. How long until we have a Bluegillzilla horror movie?

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Scary invaders in Long Island Sound

Venomous and scary-looking Pacific lionfish are invading the US East coast, as far north as Long Island Sound.

Divers have captured hundreds of lionfish this summer. “For us to be finding that many, there must be thousands and thousands more out there,” said Todd R. Gardner, a biologist at Atlantis Marine World aquarium in Riverhead. “It’s a population explosion.”

Nobody knows how the lionfish arrived, what the impacts are, and whether they'll survive winter's cold water (doubtful).

Increasing Atlantic sightings suggest that lionfish are in the Atlantic to stay, at least in the warmer waters further south.

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Invasion of the scary ocean blob creature

A mysterious rubbery "blob" creature that resembles scrambled eggs is smothering the ocean bottom in New England and beyond, and scientists are worried.

"This thing is ugly. It has no socially redeeming virtues," said Ivar Babb, after a recent study of the blob near Long Island.

The blob is an invasive sea squirt that reproduces quickly and forms large mats covering the ocean bottom, sometimes resembling scrambled eggs. Like some sort of scary ocean monster, it can change shape and has no known predators. At the first international conference on the blob, scientist Mary Carman even wondered if it's something newly evolved.

Invasive species smothers George's Bank, threatens valuable fish and scallops. It sounds like science fiction but it's real.

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