Natural Predation on invasive Lionfish!

Source - read it!

And I cite.

Seen any Fish population explode as of late?
Yes we have: Lionfish in the Caribbean! But those are invasive introduced species that so far lack any predators - betcha that in 10 years, the picture will be vastly different!

That was yours truly three years ago.

And now, it appears, some Caribbean predators are already, slowly slowly, developing a taste for those Lionfish.

Watch.

Stories here and here. 

Pretty cool - but of course for that to work, we need predators! 

And when it comes to the latter, sobering research reveals that matters in the Caribbean are far from ideal, and yes that would be a gross understatement. But I stick to my prediction - coupled with human intervention that is effective and remains vital, this issue is likely to resolve itself.

Fingers crossed!

Feeding Lionfish to Bull Sharks?

Source.

Watch this.

So Cassell is back.

Which immediately begs the question, with or without Spot's fins?

But I'm obviously digressing.

The uncontrolled feeding of Lionfish to Sharks is a bad bad bad idea - the more as contrary to Playa where they encounter female Bull Sharks that are indeed conditioned and rather mellow, the Bulls in Cancun are feisty males that have already bitten people. With that in mind, does anybody think that the authorities are gonna be as delighted as Cassell appears to suggest?

Having inquired with a friend, his answer is

Hola Mike. I tried to feed lion fish to the bulls and they spit them out. Nobody is feeding in Cancun because it is a marine park and it is not permitted. Actually i don't think these guys have a permit to do what they want.

And why am I not surprised - caveat emptor!

To be continued no doubt!

PS! - less than a day after posting this, the video has been made private...
As I said, caveat emptor!
PPS - as per the comment below, the video has been re-edited and re-posted!
PPPS - and now the video has been retracted. Wow.
 

Sharks eating Lionfish!

Cool story, cool pics.
Caribbean Reef Sharks are being taught to eat invasive Indo-Pacific Lionfish (more details here).

Story and slide show here.

Scanning the Horizon

Caribbean Lionfish Hunter (yup this is a link)

A large group of smart people have gotten together this September and defined some nascent conservation issues for 2010, both threats and opportunities.

The resulting paper is called A Horizon Scan of Global Conservation Issues for 2010 and you can download it here, and yes, as you should, you would have to pay for that. Or, you may want to consult the useful synopses posted on Conservation Bytes and Planet Earth Online.

It spans a list of 15 topics, some of which surprising like International Farmland Acquisitions by foreign governments, some somewhat obscure and eclectic like the effects of Nanosilver in Wastewater, some visionary as in Synthetic Meat or releasing Aerosols into the Stratosphere to combat Global Warming to outright scary as in Artificial Life.
In very general terms, they all illustrate the complexity of our environment and the vast, and often totally unexpected ramifications of our actions upon it.

As in the case of the Lionfish invasion of the Western Atlantic.
Likely the progeny of aquarium pets that escaped or were discarded in Florida during the early nineties, they have completely overrun the Caribbean and are inexorably threatening South America.

You can check out the progression here.

This what the paper says (links are mine).

Invasive Indo-Pacific Lionfish.
Small numbers of predatory Indo-Pacific lionfish (mainly Pterois volitans) were first recorded in waters along the eastern coast of the United States in 1992 .
The source of introduction is uncertain. The rate of lionfish range expansion was initially slow, but increased markedly after the colonisation of Bahamian coral reefs in 2004.
Lionfish are now established throughout most of the northern Caribbean and have been recorded as far north as Rhode Island and south to Colombia. Where they are established, lionfish are found at densities far exceeding those reported for their native range (e.g. > 390 lionfish/ha in the Bahamas compared to about 80/ha in the Red Sea).
Lionfish grow to a maximum length of about 45 cm, and prey on a wide variety of fish and invertebrates. On experimental reefs in the Bahamas, young lionfish reduced the recruitment of native coral reef fish by nearly 80%; the effects of lionfish on natural reefs are still unmeasured.
Lionfish are protected by venomous spines, and while small lionfish can be eaten by large groupers, such predators are rare throughout the Caribbean.
Lionfish are, however, now being fished and offered on the menu of some Bahamian restaurants.

The pests obviously have no "natural" predators in the Caribbean and the local predators that could fulfill the role of regulating their population, like the larger Groupers and the Sharks, are severely depleted. I fear that despite of the valiant efforts of those who promote fishing and eating them (nice collection of recipes here), they are there for good, like, say, the cane toad in Oz (and alas, in Fiji as well).
Maybe, eventually, the Lionfish populations will somewhat balance out, the more as there is evidence that all individuals are the descendants of very few females and that, at least in theory, after experiencing such a severe population bottleneck, they would eventually have to crash back to their effective population size, like the Cheetahs. Maybe, some local predators, parasites or pathogens will learn to exploit the new resource and thus keep the numbers in check.
But it sure is a very very long bet and not likely to happen anytime soon, at least not soon enough to be of real practical use.

Thing is that ever since we've "evolved" to become a global nuisance, these migrations and infestations have become so frequent to constitute the norm rather than the exception.
Just think about our animal baggage, be it domesticates, many of which have gone lethally feral, stupidly introduced species like Fiji's ubiquitous and invasive Minah and Mongoose, or unwanted followers like the Norvegian Rat or the Bedbug. Or the plants, be it agricultural or ornamental, like the Traveller's Palm I'm looking at whilst writing this is Fiji - originally, endemic to Madagascar!

And recently and as always, mostly unwittingly, we've started meddling on a truly epic scale.
By building canals we've created highways for marine invasions between the Med and the Red Sea and between the Pacific and the Caribbean. By heating up the planet, tropical pests like disease-bearing Mosquitoes, Rodents and Fire Ants and pathogens are ever expanding (and check out this example of how anthropogenic marine invasions are affecting Great Britain) and according to the above mentioned paper, there's a risk that as the Arctic melts, it will lose its function as a barrier between the Atlantic and Pacific Oceans, with unknown consequences for those two ecosystems - as in: adios Deadliest Catch!

Anyway, I'm ranting as usual.
All I wanted to say is that it sure is complicated and always interconnected - and that we should never forget that Marine, and Shark Conservation are but one facet of a much bigger and alas, equally bleak picture.

OK, back to the Sharks.

Connected!

Have you read Predators as Prey?
If not, download it now!

Here's another very actual example from the Caribbean.

Sharks, barracuda and other large predatory fishes disappear on Caribbean coral reefs as human populations rise, endangering the region's marine food web and ultimately its reefs and fisheries, according to a sweeping study by researcher Chris Stallings of The Florida State University Coastal and Marine Laboratory.

“I examined 20 species of predators, including sharks, groupers, snappers, jacks, trumpetfish and barracuda, from 22 Caribbean nations,” said Stallings, a postdoctoral associate at the FSU Coastal and Marine Laboratory. “I found that nations with more people have reefs with far fewer large fish because as the number of people increases, so does demand for seafood. Fishermen typically go after the biggest fish first, but shift to smaller species once the bigger ones become depleted. In some areas with large human populations, my study revealed that only a few small predatory fish remain.”

“Large predatory fish such as groupers and sharks are vitally important in marine food webs,” Stallings said. “However, predicting the consequence of their loss is difficult because of the complexity of predator-prey interactions. You can't replace a 10-foot shark with a one-foot grouper and expect there to be no effect on reef communities. Shifts in abundance to smaller predators could therefore have surprising and unanticipated effects."

Surprising indeed!
Did you read the post over at Shark Diver about the Lionfish invasion of the Caribbean?
It proposed that one should start marketing them as food, a suggestion that ties in beautifully with centuries of Southern French cuisine where any self-respecting bouillabaisse contains a generous helping of delicious rascasse, or Mediterranean Scorpionfish.

Here's what the original paper (read it!) says.

Predicting the ecological consequences of changes to the structure of predator communities is difficult. Different sized predatory fishes may perform various functional roles and can have drastically different effects on the diversity and abundance of prey species. Furthermore, loss of functional roles can lead to decreased ecological stability and ecosystems can become both less resilient to catastrophic phenomena such as cyclones and less resistant to invasions by exotic species.

The recent invasion of Indo-Pacific lionfishes (Pterois volitans and P. miles) in the Caribbean may have been facilitated by overfishing large predators capable of controlling their rapid spread and population explosion and is alarming considering the strong predatory effects lionfish can have on native fishes.
Management of human impacts on entire functional groups may therefore be more important than targeting specific taxa but tests of functional redundancy among predatory marine fishes is sorely needed. In addition, incorporating the effects of environmental variation, multiple human stressors, and linkages in interaction webs with socioeconomic factors that lead to overfishing may improve management and conservation in coral reef systems.

There you have it: everything is connected.
Next time anybody asks you, tell them 'bout the Lionfish!