Article - Releasing Nemo a Disaster for Native Fish

[John_Brandt]

Releasing Nemo a disaster for native fish


By Amitabh Avasthi
New Scientist Magazine
June 30, 2004


Exotic predatory fish that could devastate local marine ecosystems are appearing off the US coast. These and other ornamental fish are thought to have been released by careless aquarium owners, and could harm fisheries, introduce parasites and endanger native species.

In a worrying development in June, scientists at the Florida Keys National Marine Sanctuary found a pair of orbicular batfish, a popular aquarium fish endemic to the Pacific Ocean. The fish were captured to stop them breeding and competing with local fish.

The move follows increasing sightings of exotic species not native to the area, including popular aquarium fish such as orangespine unicorn fish, raccoon butterfly fish, several varieties of tang and angel fish, and the predatory lionfish. All come from the west Pacific, the north-west Indian Ocean and the Red Sea, yet they have been seen at 32 sites off Florida.

"It's a Finding Nemo story," says Brice Semmens, a marine biologist at the University of Washington, Seattle. "Individuals are releasing their pet fish with the best of intentions, but in the wrong ocean. It is a really bad idea."

Alien species

The aquarium trade has long been suspected of introducing alien species, but the link has never been proved. So a team led by Semmens compared figures from imports of tropical marine fish into the US with sightings of exotic fish in the wild recorded by REEF, a non-governmental organisation, between 1993 and 2002.

Statistical analyses on random samples confirmed that fish species imported in the highest numbers are those mostly likely to have been sighted off the US coast. The researchers ruled out the ballast water picked up and discarded by ships to maintain stability as a cause for the introduction of exotic fish. "Their home ranges do not overlap with shipping routes," Semmens says.

Most of the exotic fish have yet to establish a viable population, but scientists are worried about the ecological and economic impact of the increasing numbers of lionfish. Once found at only three sites in Florida, this highly venomous fish has recently been seen in waters from North Carolina to New York.

In their native habitat, lionfish prey on a wide variety of fish, shrimps and crabs. "Introduction of the lionfish is an ecological quantum leap for local fishes that have no experience dealing with this voracious predator," Semmens says.

Dumping danger

Walter Courtenay, a research fishery biologist with the US Geological Survey, suspects that dive boat captains hoping to attract more customers were more likely at fault than pet owners. But biologists agree that now the fish is established, it may be impossible to eradicate.

In the coming weeks, the US National Oceanic and Atmospheric Administration and representatives from the aquarium industry will join forces to educate the public about the dangers of dumping pet fish into the ocean.

Congress is also considering setting up screening for fish imported by the aquarium trade, by extending legislation aimed at preventing the introduction of invasive species via ballast water.

http://www.newscientist.com/news/news.jsp?id=ns99996093

 

[Anonymous]

By Amitabh Avasthi
New Scientist Magazine
June 30, 2004


. "Introduction of the lionfish is an ecological quantum leap for local fishes that have no experience dealing with this voracious predator," Semmens says.

I don't agree with releasing any organism to the wild outside of it's natural habitate, nothing good ever comes from it. However the above point is a bit silly. Show me an ocean anywhere in the world without obligate piscivores. There are plenty of native voracioius predators in the Florida waters. Furthermore, I seriously doubt the release, and even establishment of a Pterios species in those waters will make much of an impact. It's not like the establishment of the nile perch in lake Victoria in Africa. There is a lake with NO large native piscivore. Once it was introduced, the native cichlid populations were/ are being demolished.
Hardly the situation here. However, I disagree with the practice, and wish it didn't happen.

Did you know that here in California, only ONE of our game fish species is native? The Sacramento perch. All the rest, Largemouth, spotted, smallmouth, redeye basses - all the different sunfish, trout, catfish etc were all introduced by Fish and Game.

Jim

 

[John_Brandt]

Jim,

The point being made is that American coastal marine fish have never seen anything like a lionfish, neither in real time nor in any meaningfully recent ancestry. They may not react to it as a predator because natural selection has not altered their behavior to avoid these fish. Lionfish evolved in different oceans.

The impact it will have is yet to be seen. But obviously it will have some, as it is a new predator that has appeared in a geologic instant.

 

[Anonymous]

Good points John, I agree.

 

[Mihai]

Well, I think that the fish should be able to avoid it anyway. I doubt that the small fish keep a list of predatory fishes encoded in their DNA. I think that it's rather: "if it's big enough to eat me, I'll stay away". I'm no specialist, but I see that the creatures in my tank are scared of my hand and I never predated on them .

M.

 

[John_Brandt]

Well, I think that the fish should be able to avoid it anyway. I doubt that the small fish keep a list of predatory fishes encoded in their DNA. I think that it's rather: "if it's big enough to eat me, I'll stay away". I'm no specialist, but I see that the creatures in my tank are scared of my hand and I never predated on them

It is encoded in their DNA. Or rather, the DNA builds a brain that has unique preconceptions about the world. Those preconceptions and pattern recognitions are directly related to the evolutionary history of any given fishes ancestry.

Reef fish present us with a profound scientific mystery. How do they know what they know? And why do they seem to know details about the world without anything like culture to teach each other? They have no opportunity to build any sort of autobiographical concepts. They cannot know their parents, nor have any idea of something like origins or destinations. They simply are.

Yet they act like they know about reefs and other fishes and invertebrates. They cannot simply hold a metaconcept like "if it's big it will eat me", because otherwise they would avoid necessary associations with larger fish. The male clownfish is 1/5 the size of his mate. Why doesn't he avoid her for fear of being torn apart and eaten? And even if avoiding large things were the only encoded imperative it would still need fine distinctions because otherwise fish would avoid reefs themselves entirely - a reef is a very big thing.

Yes, predatory recognition patterns (templates) are built into the brain structure, as well as a degree of plasticity to learn from experience. But this is nothing simple at all. A learning mechanism has to be highly sophisticated because a fish has to already have a 'notion' of what would be a good thing and what would be a bad thing. The more you begin to think about what a reef fish must accomplish the more complicated it gets.

Caribbean and Atlantic fishes presumably do not have a mental template to avoid lionfish. Additionally, the lionfish form is so drastically different from their neighbors that for all we know - fish might be attracted to lionfish.

Experiments have been conducted on many kinds of animals in which novel predators are presented to potential prey species. Usually the predator is not recognized as such. There is a lag time (sometimes many many generations) before the population of prey animals comes to recognize the new predator.

The question that reef ecologists must ask is what will be the overall affect on native ecosystems of having a novel predator such as a lionfish on these reefs?

 

[SpicyBalls]

Guess finding nemo did some good and bad for the industry..
_________________
Honda CBF1000

 

[Mihai]

Thanks John, this is enlightning. I have no counter-arguments to what you say, except that from an information theory point of view it's easy to encode something like "avoid big fish" then put a list of exceptions (e.g. nice, big, juicy female or a big fish to clean) than exhaustively list all potential threats (besides is also safer to do it this way). The only problem is that they might not know about information theory .
I'm not trying to argue with you, I'm in absolutely no position to do that: I'm an engineer - I know computers and networks, not animals. But I'm eager to learn.

Thanks for the lesson.

Guess finding nemo did some good and bad for the industry..

Huh? What was the good part?
M.[/b]

 

[SpicyBalls]

Guess finding nemo did some good and bad for the industry..

Huh? What was the good part?
M.[/b]

let's see.. good for the industry.. more interest in saltwater fish, corals, inverts... means LFS or online may carry more varieties, selling more goods, books as people want to learn more etc... more people visiting the aquariums to learn more.. which in turn they learn about the need for coral reef conservation, understand the care required to keep fish (as the doc's office tank exemplies), more revenue for the aquariums also means more dollars for research and conservation, lessens the stress to find grants/donations... more people keeping fish/corals/inverts means better understanding of the intricate needs of these organisms as someone may find what the care requirements are for say goniopora stokesi.. or for blue linkia etc..., increase demand means more research and development by aquarium suppliers or whoever, to better the reef keeping experience, whether it's a maintainence improvement, new additive, food supplement, better lighting, filtration process/technique, etc....

of course, good for the industry can mean bad for reefs/saltwater populations... over collecting of corals and fish to meet growing demand... every good above can be looked at another way as being bad for the industry or reef conservation......

and, if people are actually trying to release fish, that's saying they're trying to conserve the widlife... which as stated before, is good and bad as well.

I guess you saw nemo as being all bad eh?...
_________________
us recession 2009

 

[Modo]

Jim,

The point being made is that American coastal marine fish have never seen anything like a lionfish, neither in real time nor in any meaningfully recent ancestry. They may not react to it as a predator because natural selection has not altered their behavior to avoid these fish. Lionfish evolved in different oceans.

The impact it will have is yet to be seen. But obviously it will have some, as it is a new predator that has appeared in a geologic instant.

Kinda like the Cambrian Explosion? :wink:

 

[nanocat]

Walter Courtenay, a research fishery biologist with the US Geological Survey, suspects that dive boat captains hoping to attract more customers were more likely at fault than pet owners.

Exactly. And this is a reefer's problem, how? :roll:
What next, they'll blame the shortage of tuna on reefer's instead of canning plants and sushi bars :lol:

 

[John_Brandt]

I have no counter-arguments to what you say, except that from an information theory point of view it's easy to encode something like "avoid big fish" then put a list of exceptions (e.g. nice, big, juicy female or a big fish to clean) than exhaustively list all potential threats (besides is also safer to do it this way).

It is? What is big? What is fish?

Artificial Intelligence (AI) seems straightforward until you actually try to do it.

Just how easy is information theorywhen a free-will entity has to make a decision? We could get way off topic but this is foundational for the agument that Florida ecosystems could be 'blindsided' by things like lionfish.

 

[John_Brandt]

Guess finding nemo did some good and bad for the industry..

Well the phrase 'Releasing Nemo' is used metaphorically in the title, not literally. There have been no reports of clownfish being released in the USA, and AFAIK all the exotic fish being reported were sighted prior to the release of the film.

Nonetheless, more Americans have seen the movie than have owned marine aquariums. It will probably be used as a popular 'hook' for any news story about the aquarium trade for a long time.

 

[John_Brandt]

Kinda like the Cambrian Explosion? :wink:

Hmm.... what do you mean?

 

[Anonymous]

The Cambrian Explosion:


For most of the nearly 4 billion years that life has existed on Earth, evolution produced little beyond bacteria, plankton, and multi-celled algae. But beginning about 600 million years ago in the Precambrian, the fossil record speaks of more rapid change. First, there was the rise and fall of mysterious creatures of the Ediacaran fauna, named for the fossil site in Australia where they were first discovered. Some of these animals may have belonged to groups that survive today, but others don't seem at all related to animals we know.

Then, between about 570 and 530 million years ago, another burst of diversification occurred, with the eventual appearance of the lineages of almost all animals living today. This stunning and unique evolutionary flowering is termed the "Cambrian explosion," taking the name of the geological age in whose early part it occurred. But it was not as rapid as an explosion: the changes seems to have happened in a range of about 30 million years, and some stages took 5 to 10 million years.

http://www.pbs.org/wgbh/evolution/library/03/4/l_034_02.html

 

[John_Brandt]

I'm familiar with the 'Cambrian Explosion'. Many evolutionists wish it weren't described as an explosion as it makes the lazy-minded think of instantanous evolution (as if by saltation), and hence causes them to misinterpret Darwinism.

But what does the CE have to do with dumping a lionfish in Biscayne Bay?

 

[Anonymous]

I think a better description would be the impact that some rocky mountain BigHorn Goats has on the Olympics in WA a while back. Disrupted the local food chain and thretened to displace indiginous species, as well as destroying (nearly to the point of extinction) some local flora

:edit: goats sheep whatever, I'm not a farmer

 

[Mihai]

let's see.. good for the industry.. more interest in saltwater fish, corals, inverts... means LFS or online may carry more varieties, selling more goods, books as people want to learn more etc... more people visiting the aquariums to learn more.. which in turn they learn about the need for coral reef conservation, understand the care required to keep fish (as the doc's office tank exemplies), more revenue for the aquariums also means more dollars for research and conservation, lessens the stress to find grants/donations... more people keeping fish/corals/inverts means better understanding of the intricate needs of these organisms as someone may find what the care requirements are for say goniopora stokesi.. or for blue linkia etc..., increase demand means more research and development by aquarium suppliers or whoever, to better the reef keeping experience, whether it's a maintainence improvement, new additive, food supplement, better lighting, filtration process/technique, etc....

True, true. However, I'd argue that the people that got into the hobby because they saw the movie are the wrong sort of people to get in the hobby: they "nemo and dory in the fishbowl" kind of people. Nothing good can come out of this (fish killed, no research on blue linckias, etc).

I guess you saw nemo as being all bad eh?...

Don't get me wrong: I love the movie... it's just the effects that I don't like.

M.

 

[GSchiemer]

FWIW, MANY lionfish were caught in New York last summer. Last time I visited my friend Joe Yaiullo at Atlantic Marine World Aquarium in Long Island, he had a tank FULL of lionfish that were captured locally. It's doubtful that they survived the NY winter, but I really don't know. I've heard that there are established year-round populations of lionfish as far north as the Carolinas.

Greg

 

[leftovers]

I have no counter-arguments to what you say, except that from an information theory point of view it's easy to encode something like "avoid big fish" then put a list of exceptions (e.g. nice, big, juicy female or a big fish to clean) than exhaustively list all potential threats (besides is also safer to do it this way).

It is? What is big? What is fish?

Artificial Intelligence (AI) seems straightforward until you actually try to do it.

Just how easy is information theorywhen a free-will entity has to make a decision? We could get way off topic but this is foundational for the agument that Florida ecosystems could be 'blindsided' by things like lionfish.

You could toss in some evolutional theory there that would show that within as few as 3 generations the fish would figure out that that slow moving rock isnt a rock and pass that knowledge along while it might take 3 i wouldnt want to bet an ecosytem on that.... another non-trivial exercise would have to be a bigger fish seeing that the lion too is a tasty and SURVIVEABLE snack and the lion fish having to also adapt its hunting habits and colorations to a non-native environment...all of which are non-trival in terms of information encoding and reproduction in a system with no post partem education or imprinting...though it is far easier for the TOP of the food chain to move in than the bottom....

another example would be the snakefish in VA/MD it will reap disaster on the native fish and utterly destroy the ecosystem since its the top of the food chain....

the AI folks would love to be able to codify with the efficiency mother nature is able to...