Lionfish

[Tobnpr]

What I don't understand is her comment that they could wipe out entire reefs.

True, they have few natural predators. But that holds true as well in the tropical Pacific where they're native.

So why the population explosion, and why don't they wipe out the reefs off the Phillipines?

[rchanner]

What I don't understand is her comment that they could wipe out entire reefs.

True, they have few natural predators. But that holds true as well in the tropical Pacific where they're native.

So why the population explosion, and why don't they wipe out the reefs off the Phillipines?

I wondered about that too. It makes sense to me that the ecosystem would make a substantial shift with a change in the predatory hierarchy, but wiped out reefs does sound a bit extreme. Maybe there's a marine biologist on here that can explain it to us.

[robbiedon]

I think that happens a lot when a non-native species comes in to an ecosystem. Kudzu is not native here and is rampant but I don't know if it is as dominant in its natural habitat or those snakehead fish that have been reeking havoc in Maryland. my guess is that in their natural habitat a predator has evolved that might eat their young or eggs. I did some googleating on habitat decimation by non-native fish species.

This is from an article from the National Invasive Species Information Center.

http://alic.arid.arizona.edu/invasive/sub5/index.shtml

"Habitats that are invaded by non-indigenous vertebrates generally have low biodiversity, meaning that the variety of life currently present in the area is low. Observations of past animal invasions throughout the world have revealed that small, isolated habitats, for example Hawaii, seem to be more susceptible to animal invasion than larger landmasses, for example the continental U.S."

That would suggest to me that isolated habitats like reefs and wrecks would be susceptible.

This is from about.com. http://animals.about.com/b/2008/07/25/reef...h-fall-prey.htm

"Scientists from Oregon State University report that coral reef communities throughout the Caribbean are being devastated by the invasive lionfish. The predatory fish feeds on unsuspecting native fish with alarming efficiency. The study revealed that in a single 30-minute period, one adult lionfish consumed 20 smaller fish. Additionally, within a five-week period, the lionfish reduced the population of juvenile fish within the study plots by 79 percent.

The message is clear: shortly after lionfish invade a reef, nearly 80 percent of the other reef fish species disappear. To compound the problem, many of the native fish that fall prey to lionfish are herbivorous and feed on seaweed that otherwise crowds the reef. With many of the herbivorous fish gone, seaweed growth explodes, derailing the delicate balance of the reef."

Another part of the article said that in its native habitat prey fish develop evasive tactics but the fish in the "new" habitat aren't familiar with the danger the lionfish poses.

"The lionfish is native to the tropical regions of the Pacific and Indian Oceans. In its home range, its numbers remain in check thanks to natural predators such as groupers. Also, prey fish in its native habitat are well adapted to eluding the lionfish. But in the Atlantic, the lionfish has few predators. Prey species are unfamiliar with the danger lionfish pose to them."

I wondered about that too. It makes sense to me that the ecosystem would make a substantial shift with a change in the predatory hierarchy, but wiped out reefs does sound a bit extreme. Maybe there's a marine biologist on here that can explain it to us.

[Wolakrab]

Non-native species invasion is serious stuff....just ask any Great-Laker about zebra mussels, or ask any South Floridian about cichlids, peacock bass, and piranha.

[rchanner]

Probably like the first guy to ever eat an oyster. I am sure his "buddies" were standing around watching to see what happened.

That's kind of like the comedian that asked: Who was the first guy to eat an egg? Seriously...who was the first guy to look at a chicken and say 'I'm eating the next thing to come out of that bird's @$$'?