Coral Reef paper on clownfish collection

[spawner]

Population impacts of collecting sea anemones and anemonefish for the marine aquarium trade in the Philippines

Craig S. Shuman1, 2 , Gregor Hodgson2 and Richard F. Ambrose1
(1) Environmental Science and Engineering Program, Department of Environmental Health Sciences, University of California Los Angeles, Box 951772, CA 90095-1772 , USA
(2) Reef Check Foundation, P.O. Box 1057, 17575 Pacific Coast Highway, Pacific Palisades, CA 90272-1057, USA
Received: 27 October 2003 Accepted: 10 June 2005 Published online: 7 September 2005


Abstract
Tropical marine ornamentals comprise an increasingly important fishery worldwide. Although the potential for overexploitation of marine ornamentals is great, few studies have addressed the population-level impacts of ornamental exploitation and few ornamental fisheries are managed. Analysis of catch records obtained from collectors over a four-month period in the vicinity of Cebu, Philippines, showed that anemonefish and anemones comprised close to 60% of the total catch. Underwater visual census surveys revealed that both anemone and anemonefish densities were significantly lower in exploited areas than in protected areas. The low density of anemones on exploited reefs accounted for over 80% of the reduced density of anemonefish at those sites. There were similar numbers of anemonefish per unit area of anemone in protected and exploited sites; however, biomass of anemonefish per unit area of anemone was lower in exploited areas. Reduction of anemone removals is recommended to support the sustainable harvest of anemonefish from this region.

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If you want a PDF let me know.

andy

 

[mkirda]

Population impacts of collecting sea anemones and anemonefish for the marine aquarium trade in the Philippines

The most remarkable thing about this paper is how unremarkable it is.
Even MAC knew this years ago, and put it into every management plan I have been able to lay my hands on...

One of the first things you will notice about clownfish behaviour is how dependent they are on their anemones in the wild. You will not see one stray from an anemone... Unless it is to run away to another one! They will rise above it in search of food, but rarely stray more than 3-4 meters.

Never once have I seen a clownfish swimming around the reef without an anemone in sight.

Remove the home, the fish find a new one. Remove them all in a given reef, you won't find a single clownfish in the area.

Of course, this should be inherently obvious.
<humor> Like having an astronomer write a paper about how the sun rises in the east... </humor>

Regards.
Mike Kirda

 

[clarionreef]

In Mexico a certain biologist found that fishes tend to be more abundant in the current zones on the North and South ends of the offshore islands in the Sea of Cortez.
Although it filled no need, he trumpeted it as a revelation.
Of course there were no fisherman in the region that did not know this since 15 years old, but to have it validated by science....well, somehow its now a certified truth instead of just a regular one.
There are so many truths waiting for science to catch up, show up and chip in.
Steve

 

[PeterIMA]

I seem to recall that Steve Robinson wrote an article in Marine Fish Monthly (in about 1989) that discussed the fact that cyanide was being used to capture clownfish and was also spayed upon the anemones. Carpet anemones were noted to be scarce in the areas where cyanide was used and so were the clownfish (partly because their host anemones were disappearing). So, I agree that this is a case where the scientists from ReefCheck are rediscovering what was documented long ago.

When is ReefCheck going to publish some data that shows how their underwater surveys (funded through MAMTI) are related to assessing sustainability? I am still waiting for an answer to my questions concerning how the MAC is tying net-trainings to the underwater surveys conducted by ReefCheck. Is the MAC using the ReefCheck data to limit the number of collectors trained in unsustainable areas? How does the ReefCheck surveys support better management of the aquarium fish fishery and conservation of the coral reefs? Isn't that what ReefCheck is being funded to do through MAMTI?

Peter Rubec, Ph.D.

 

[nanocat]

Cyanide to catch clownfish? I'd always heard they swam so slowly that cyanide wasn't used? :?:

 

[clarionreef]

Theres is a handicap in using whats 'logical' to us here.
IF, a squirt bottle is whats in hand...a squirt bottle is what you use on everything.
You know, like an amatuer mechanic who uses vice-grips for everything and strips all the bolts.
I watched divers all day long doing this..day after day.
If a clownfish came into the picture...so be it.
Nothing special for him.
Steve

 

[PeterIMA]

Another comment about carpet anemones and cyanide. During the late 1980s, I had the opportunity to visit a pet shop in New York City. The owner complained that the carpet anemones from the Philippines were lousy (they were dying in his tanks). The survival of the carpet anemones may have been poor because they had been doused with cyanide, and then collected and exported.

I should also note that a spatial correlation between low abundances of clownfish and low abundances of carpet anemones in the same area does not prove they were overharvested. They could have died from cyanide exposure on the reef (since the research of Dr. James Cervino has demonstrated that even one exposure to cyanide led to mortalities of 8 genera of corals and one species of anemone).

I believe that anemones in the Philippines have disappeared both from being over harvested and from being exposed to cyanide used by cyanide fishermen on the reefs.

Peter Rubec

 

[Kalkbreath]

Oh boys.......... Seems you over looked that there are the same number of clownfish per host in the protected and unprotected areas.[just less anemones around] that means even in the collection area where they collect amost entirely clownfish,the number of clownfish per host are still in a natural balance. No sign of over collection at all. If the hobby was collecting too many fish then the number of fish per anemone would fall. If they were over collecting the anemones then the number of fish per anemone would increase. You really think the collectors are collecting both the fish and the Anemones in a perfect ratio?Being that clownfish out sell anemones several thousand to one , I sure doubt it! Unless those Cebu anemones each hold a thousand or more fish each!
I am sure that even fish species our industry doesn't collect are less numerous in the unprotected waters. The protected areas are always healthier and all animal life is more abundant.There were most likely less fish and anemones in that area two hundred years ago . Thats why they chose the OTHER area to protect.
In the Florida Keys there are less fish living in the grass beds and more animals living around the reefs....which did the Gov decide to protect? :roll:

 

[Kalkbreath]

Speaking of Grass beds.......Did I hear carpet anemones? They live in sandy grass areas not reefs > Whats the protected area like ? The area they used to compare side by side to the collection zone ?
You need to compare apples and apples in order to have any substance.
Further more, If I collect five hundred clownfish in an area.......then yes
there are less clownfish in the area.Its only when the numbers dont stabilize that over collection is taking place. Its impossible to collect fish without having the fish you collected missing from the area.

 

[Kalkbreath]

Its like mowing the yard.
Yes, there is less grass the day I cut it ....and if I keep cutting it ,
it will never get as thick as it would if I never mowed it.
But as long as it continues to remain the same week after week.......then I'm not cutting it too short.

 

[Kalkbreath]

Lastly, Peter thinks anemone collectors collect carpet anemones with juice!
Whats next Peter, live rock collectors must be using cyanide as well because you once saw some bleached out live rock in a retailer in Ohio? :lol: :wink:

 

[mkirda]

Cyanide to catch clownfish? I'd always heard they swam so slowly that cyanide wasn't used? :?:

Not that they are built for speed, but they can swim faster than you or I.
Normally though, they will only leave their anemone for another nearby one.

Cyanide is absolutely not needed for clownfish, that much is sure, especially for the six or seven different species I saw taken last month. Nets work just fine.

That being said, the very fact that clownfish tested positive repeatedly for cyanide tells us that cyanide is in fact used for their capture by some juice collectors. Which is sad given how easy it really is to capture them. Anyone, and I do mean anyone here who can dive, could learn to capture clownfish with nets within 10 or 15 minutes of observing a Filipino collector.

Kalk is also quite incorrect about carpet anemones. While some do reside in sandy areas, many others reside directly on rock surfaces, typically with their foot in a crevice or hole. One particular carpet species lives in the sandy areas, and it only hosts a single particular clown species not all that common in the trade. This is probably where he gets his flawed generalization from. I saw many more carpets on the reef than on the sand.

And lastly Kalk, if you want your questions answered about Reef Check, I'd suggest that you call Gregor Hodgson directly. His number is listed.
He loves talking to hobbyists.

Regards.
Mike Kirda

 

[Kalkbreath]

the very fact that clownfish tested positive repeatedly for cyanide

they tested in around ten percent and most likely that was in 1995 ......."repeatedly"?
Your spinning to furture your cause.
Two fish testing positive would count as repeatedly with you guys.

 

[clarionreef]

Colored carpets have been decimated everywhere the trade exists.
Only Sri Lanka still has any real numbers coming in and those are to be regarded with reference to the unprecedented distances they are coming in from and the greater efforts as well.

Old anemones that the trade wants get taken and they don't grow back like the yearly clownfish crop.
Without anemones...the clownfishes decrease....
With anemones not taken...sure, the numbers of younger clownfishes increase...in the anemones that are there to house them.
As the population is totally dependant upon available anemone population...there can be more young clownfish per surviving anemones and fewer clownfish in general thruout the area. There are no clowns if the anemones go.
Now Kalk. Cut and paste that...twist it a bit, and make it come out as good news.
Steve
Peter never said that carpets were taken w/ cyanide. They have however been poisoned with cyanide incidental to the collecting of the fish.