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Rocha

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Posts posted by Rocha


  1. Maybe the spearfishers could satisfy their bloodlust (hunting tradition) by shooting tame Lionfish instead of tame Grouper? Could create awhole new sport and save the economy?

     

    Spearfishers in the Caribbean mostly shoot fish for food, and who would trade a grouper for a Lionfish? But as Bart says, even if we gave a spear to every diver in the Caribbean, eradication at this scale is virtually impossible. I am sorry to say that Lionfish is here to stay, the local fauna will just have to get used to it.


  2. Hi Jim, I jumped the gun here because I was curious too and asked some people. Just got an answer from Jack Randall, who suspects the fish in your picture is Apogon monospilus, or the Moluccen Cardinalfish (aka Yelloweyed Cardinalfish). You can find more information about it here:

     

    http://fishbase.de/Summary/speciesSummary.php?ID=60354

     

    The strong red coloration of the fish in your photo is what was confusing me, but Jack says the background color in this species is variable from pale yellow (like the one shown in Gerry Allen's book) to vivid red like yours.


  3. Bart is correct, number 1 is a juvenile Scorpionfish, very hard to ID at that size without a full view photo, if I had to guess I would also say Barbfish (Scorpaena brasiliensis), it is not a Toadfish, of that I am sure.

     

    All others are color variants of the Seaweed Blenny (Parablennius marmoreus) as Bart has already said.


  4. I love the last couple of paragraphs:

     

    Commercial whaling has been banned worldwide since 1986 but Japan justifies its annual hunt as scientific research.

     

    Meat not used for study ends up in restaurants and shops.

     

    In other words, 99.9% ends up in restaurants and shops.


  5. Congratulations and good luck! If she plans on getting into grad school (which is pretty much the only option unless you want to work for places like SeaWorld), ask her to contact me, I am a marine biology professor at University of Texas, Austin.

     

    Cheers,

     

    Luiz


  6. In fact, the Japanese have argued that whales (some of them are now 1% of their pre19th century population) are competitors for fish, and thus need to be regulated, an argument many fishermen will support, whether the science is there or not.

     

    Exactly Drew. Coincidentally, that's the same argument fishermen in Florida are using to try to re-open the Goliath Grouper fisheries, they say the groupers are competing with them for the fishes. I think we talked about this before in some other topic, but to me, it's like killing Cheetahs because they are competing with humans for Gazelles, senseless.


  7. Haha, we are totally off! You are right James, there are a lot of studies that indicate the survivalship of mouthbrooders versus broadcast spawners is actually very similar because of the parental care investment of mouthbrooders. But that is in a perfectly balanced ecosystem. The ability of a population to recover (or even maintain its numbers) from impact is much higher in broadcast spawners, there is a direct correlation between the number of juveniles that survive and the numbers of adults in the area. In other words, competition influences it a lot, especially in reef fishes.

     

    Real world example: the Banggai Cardinal has the capacity to "make" 10 new cardinals per month, 5 of which survive. The clipperton angel has the capacity to make 300, but only 5 survive because the reef is already saturated with angels. Say you fish out 100 cardinals and 100 angels, now a lot more of the 300 angels (say 50 or so) will survive because of newly open suitable habitat, versus the constant 5 from the cardinals.

     

    Drew, the IUCN is horrible when it comes to website updates. They take ages, in the last 2 years a group of specialists (inlcuding Ross Robertson, Howard Choat, Jack Randall, and myself) evaluated and put more than 500 species in red list categories (most least concern), but none of that was uploaded yet... I will look into the Banggai cardinal case and see what is going on.


  8. This discussion is getting very interesting, James, what I meant to say with the BC case was that the Banggai is not your typical reef fish, most reef fish are broadcast spawners with much higher fecundity, so even if we had, say a wrasse or angelfish, with the same distribution as the BC, those extraction levels would probably not deplete the population the way they did the BC. Now, don't take me wrong, I am not defending the aquarium industry and I know for a fact that it has an impact. What I am trying to convey is that the impact of the aquarium industry is the least of our problems when we compare it to the impact of fisheries or even El Ninos or global warming.

     

    Back to the case at hand, the estimate on Clipperton angels that I got from Ross was tens of thousands distributed throughout the island. This is what usually happens to endemic fish in small isolated locations, they are usually released of competition (because of the impoverished fauna) and have large populations.

     

    About Clippo's quote below:

     

    I also think it is unethical and inhumane given the likelihood of high mortalities in shipments as evidenced by previous commercial attempts.

     

    How is the above different from any other location? There is mortality and inhumane treatment in all reef fish collections, this is by no means restricted to Clipperton. Fish are taken from beautiful natural reefs and put in small plastic bags for days, and then in small glass containers for the rest of their lives (if they survive). Maybe you should start a petition to stop all reef fish trade :drink:

     

    Drew:

     

    I'm pretty sure that the BC deserve to be on that list, especially in the Banggai Islands where I think only half of the islands have populations and many are dwindling due to collection and habitat destruction.

     

    We have two IUCN lists, a global threat list and a regional list. The Banggai is off the global list since it is very unlikely that it will go extinct now. But it is regionally threatened at the Banggai islands... We do this all the time, there are a lot of large parrotfish that are endangered in the coral triangle only (due to overfishing) but doing fine elsewhere.


  9. I'm not sure I agree about the self-regulating facet though Luiz - if that was the case then the Bangaiis wouldn't be in trouble. I think it's the remote location that helps so much in this case.

     

    Cheers

    James

     

    Bangais were in trouble because they were cheap (so the collectors wanted to sell a lot for profits)! And a *very* small natural population limited to an easily accessible place 100X smaller than Clipperton. And the fact that they are mouth-brooders with much smaller clutches than angelfish... Self-regulating works for rare species in isolated (or deep) locations, nobody wants to go to Clipperton to collect fish and sell them for $50 when they can do that at the coast, but if they sell thousands of them the price will inevitably drop....

     

    Now back to the Bangais, they are almost completely out of trouble thanks to captive breeding. Captive bred stocks were even released in the wild and the populations are much bigger now than they were a few years ago. I have been doing assessments and evaluating conservation status of reef fishes for the IUCN for the last 10 years, and I cannot think of a single case of extraction for aquaria being the main cause of a species getting into the red list, with the exception of the Bangai Cardinal, which is recovering now.


  10. Hi Clippo,

     

    I was one of the experts on the recent IUCN workshop to evaluate this species. We asked Ross Robertson (with whom I work closely) about his feel for what the population levels were in the 90's and he said that the fish was very abundant. We did, however, leave it as Vulnerable, as we did all species with such a small range.

     

    As far as collection goes, consistent (but sustainable) collections are much better coped with by fish populations than single large collections, and that's what I am trying to say regarding reef fish in the aquarium trade, that extraction levels are probably not going to be a threat for most species. 50/year certainly is not...


  11. Hi Clippo,

     

    You are correct, the fish is Holacanthus limbaughi, I have no idea where my head was when I wrote Holacanthus clippertonensis :drink: . The source for the news that the ship was removed is this:

     

    http://www.lloydslist.com/ll/news/viewArti...eId=20017756065

     

    And also an e-mail that I received from Tahitian authorities last week.

     

    So, in your post above you mention several things other than reef fishes. Why protect only the fishes? I would be much more inclined to sign it if it was a petition to transform Clipperton in an off limits biological reserve. Nothing allowed, no tourism (which it doesn't support anyways), no shark fishing, etc. That I agree would protect the ecosystem as a whole, but I don't see a lot of advantage in protecting only the reef fishes (which as I mention in my first post, are very safe with current levels of extraction).

     

    Even though I have never been to Clipperton, I have traveled extensively and made reef fish populations surveys throughout the planet, including many locations very similar to Clipperton in size and isolation. Everything I know about population dynamics in fishes indicates that extracting 50 angels (or even 500) would not make a dent in the population. If the population is small enough that extracting 50 is a problem, then that population is genetically doomed anyways.

     

    Cheers,

     

    Luiz


  12. Hi Drew, it is possible, but not very likely. The investment to catch (and keep alive) 2000 of these guys is just too high. Think about it, you need a much bigger boat, more divers, a better infrastructure on land, etc, and most collectors don't have that. Remember, we are speaking about angelfish, we can't just cram 100 of those in a small tank. And you have to have a distributor willing to take the risk too... Lots of variables.


  13. Just to clarify, the tanker that they refer to in the link above was safely removed from the reef. There was minimal reef damage and no chemicals leaked.

     

    On a secondary note, and I am sure this will cause some discussion, I really don't think we should worry too much about reef fish collection in Clipperton. There is only one species that is valuable to the aquarium trade there, which is Holacanthus clippertonensis, an angelfish. Also, there is only one collector that goes there with any type of regularity, a Mexican-based operation that goes there once a year at the most, but he hasn't been there for three years. It is VERY expensive to go collect reef fish in Clipperton, the place is very isolated (about 1300km from shore).

     

    Now, since we are talking about the extraction of reef fishes, in this case for the aquarium trade, here is a thought. The aquarium reef fish trade is one of the best self-regulating fisheries that I know. Reef fishes (especially the rare and expensive ones) are NOT like food fish. If you dump 1,000 pounds of grouper on a the market one day, they will sell for $6 a pound, if you dump 20,000 the next day, they will sell for the same $6 because people eat grouper and food prices don't vary much. Now, if you spend thousands of dollars to organize an expedition to Clipperton and capture a few dozen Holacanthus clippertonensis, you will be able to sell them for say $500 each. If, instead of collecting a few dozen you get hundreds or thousands you will quickly saturate the market and Holacanthus clippertonensis prices will drop like rocks (there are not a lot of people out there willing to pay $500 for an aquarium fish). For this simple reason aquarium collectors don't over-collect rare species; for their own benefit they want to keep the prices high.

     

    My point is, conservation, like everything else, should work around priorities. There are many, many other places in need of much more urgent protection (Philippines, Indonesia, don't get me started). Clipperton is very well protected by its isolation and the fact that there is no source of freshwater (hence no settlement) on the island. So I say in this case leave it alone.

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