Reform?Ban?limit?.......Get your heads out of the araganite

[Kalkbreath]

Then lets be more precise......You tell me how many islands this hobby collects from out of the total number of islands in the world? :wink:

 

[mkirda]

Then lets be more precise......You tell me how many islands this hobby collects from out of the total number of islands in the world? :wink:

Kalkbreath,

You agree to my rate of $50/hr and give me the address I should send my invoice to, I'll be happy to research that number for you. You want those numbers at high tide or at low tide? And do you have a lower limit in square meters for what you would consider an 'island'?

Regards.
Mike Kirda

 

[blue hula 2]

Then lets debate those specifics.......YOU tell me what findings Leeds YOU to believe what you do.......Explain how collecting from less then 1% of the worlds reefs can effect the remaining 99%?

OK I'll bite.

Contentious point #1: Only 1% of the world's reefs are subject to aquarium collecting.

1. Indonesia has approximately 50,000 km2 of reef representing 17% of the world's total (www.reefbase.org).

Approximately 85% of this is considered at risk from human activities (Reefs at Risk, 2002).

A very common activity throughout the archipelago is likely aquarium fish collecting. This opinion is based on discussions with exporters with whom I have worked who were very frank about the fact that
(a) their boats travel far and wide collecting fish and
(b) their boats are having to travel further and wider to attempt to maintain collection levels

2. The Philippines has approximatley 25,060 km2 of reef representing approximately 8.5% of the world's total reef area (www.reefbase.org).

Approximately 97% of these reefs are considered at risk from human activities.

Aquarium fish collecting is very intense in a number of areas - for example, Danajon Bank, the second largest double bank reef in the world, is picked clean along much of its length. This opinion is based on the 3 years of field work I did in the area .

3. The total area of reef in the world is 306,000 km2 (approximately). So, if only 1% of the area is harvested, this would related to 3,060 km2

Now let's say conservatively that of the total reef in the Philippines and Indonesia that are "at risk" (69,000 km2 combined), only 50% of it is subject to aquarium collecting (rather than 97% and 85% respecitvely and totally ignoring the information provided by people in the field), this would make 11% rather than 1%. And it totally discounts all the collecting areas in Australia, US, Sri Lanka, Maldives and those few tiny islands in the South Pacific.

And I restate, I do not believe for a moment that only 50% of reefs are subject to aquarium collection given the wide ranging boats, scattering of villages / high population density throughout these archipelagos, and the strong village networds of the consolidators / exporters.

Contentious point #2: what you do in one small area doesn't matter to the rest.

It most likely does. Populations among locations are linked by larval recruitment dynamics (see for instance, research by Peter Doherty and Bob Warner). The degree of "connectivity" among populations depends on prevailing currents and the characteristics of the individual fish species (how long their larval stage is, how well they swim, where in the water column they lurk etc.). Some locations will be important supply areas and others important sink areas.

It is very simple. If you hammer a supply area, you will have a significant impact on the sink area as well. The problem is that generally, we're not too discriminating in terms of where we weald that hammer.

And this doesn't even address the issue of endemic species where hammering an area home to endemic species represents a major threat to global biodiversity (Banggai cardinals jump to mind).

So, one can hide behind the numbers and say "oh, but my contribution is just a tiny drop in an ocean of problems". This attitude is pretty reckless given how ignorant we are of most of the species we collect (age at maturity, growth rate, mating patterns etc.). When you think that almost 30% of fisheries worldwide are overexploited and in decline (www.fao.org), and I'd say ignorance and arrogance were contributing factors in many cases. Why would we think marine ornamentals are any different ?

 

[clarionreef]

Dear Hula,
We were having fun here in our little therapy group. A Kalk posting early in the morning is like a double expresso..., then you gotta show up with all that logic, reason, experience and science.
Steve
PS. I thought the Danajon Bank was depleted in 1982!
I can't imagine it today.

 

[blue_hula]

Dear Hula,
We were having fun here in our little therapy group. A Kalk posting early in the morning is like a double expresso..., then you gotta show up with all that logic, reason, experience and science.
Steve
PS. I thought the Danajon Bank was depleted in 1982!
I can't imagine it today.

Dear Steve,

Terribly sorry to have spoiled the fun. Nothing like an overly long post full of facts for killing a thread :wink:

Danajon Bank, among others, is terribly depleted. And one of the reasons why I think that attention to cyanide is essential but insufficient. I don't understand how an area can be certified as sustainable without focused attention on determining what LEVELS of exploitation are sustainable!

As of 2001, many of the coral reefs surrounding islands on the inner bank in the Barangays of Talibon, Getafe and on to the west are heavily overgrown with algae, primarily sargassum and very silted up. Visibility is poor and you can swim for 20 minutes and see fewer than a dozen (small) fish. The exceptions are some of the community-based marine protected areas where fish abundance of some species has rebounded very quickly. The reefs however remain in silty, overgrown condition. There are also a few exceptions outside community sanctuarios with good fish diversity but I'll leave it at that. They are in the precious minority.

If you are short on caffeine jolts I can still recommend diving on Danajon Bank as an alternative. Nothing like a neighbourly dynamite blast while you're underwater to give you that nescafe buzz.

Cheers,

Blue hula

 

[mkirda]

]

OK I'll bite.

{snip a great many facts...}

Blue Hula,

Thanks for 'blowing the doors off' Kalkbreath.

Ah, science. Like a breath of fresh air...

Regards.
Mike Kirda

 

[Kalkbreath]

Then lets debate those specifics.......YOU tell me what findings Leeds YOU to believe what you do.......Explain how collecting from less then 1% of the worlds reefs can effect the remaining 99%?

OK I'll bite.

Contentious point #1: Only 1% of the world's reefs are subject to aquarium collecting.

1. Indonesia has approximately 50,000 km2 of reef representing 17% of the world's total (www.reefbase.org).

Approximately 85% of this is considered at risk from human activities (Reefs at Risk, 2002).

A very common activity throughout the archipelago is likely aquarium fish collecting. This opinion is based on discussions with exporters with whom I have worked who were very frank about the fact that
(a) their boats travel far and wide collecting fish and
(b) their boats are having to travel further and wider to attempt to maintain collection levels

Lets see......less then 2000 boxes of fish come out of PI each week You really think collectors are collecting 2000 boxes over 25,000 square km2?............this would mean some of those boxes are comming from reefs 400 miles away from the Airports? If your going to include one fish per square kilometer as collection sites .........then yes 11% of the world reefs have collection........But only 1% of the worlds reefs have collection greater then one fish per square kilometer per week...........If there was one fish collected in the Acention islands this would fit {YOUR} conditions for "hobby collection" But if we limit "hobby collection " to mean collection levels greater then that of one grouper{ one fish per square kilometer} We would find either the areas of hobby collection to be very small in number or the number of fish removed per reef to be three fish per square MILE! :lol: So if your numbersare true.........then how could removing three fish per square mile ,per week effect Larval numbers :wink:

 

[blue hula 3]

I must be a glutton

Lets see......less then 2000 boxes of fish come out of PI each week You really think collectors are collecting 2000 boxes over 25,000 square km2?............this would mean some of those boxes are comming from reefs 400 miles away from the Airports?

Kalk - where does the estimate of 2000 boxes come from ?

Even this number would be an underestimate of the number of fish caught as it excludes mortality during collection and up to export ... Dr. Elizabeth Wood (www.mcsuk.org) in the most comprehensive review of the aquarium trade to date suggested that this mortality is around 20-30% in the Phils on top of your estimate.

I did say that I'd assume 50% of the reefs in the Phils supports aquarium collecting which would make the area 12,500 km2 rather than 25,000 km2.

However, it is certain that fish are transported long distances from collection point to exporters.

Bali export lists include Yellow striped Premnas (found only in Sumatra) and Banggai cardinals (found only in the Banggai islands of Sulawesi).

Sumatra => Bali - 800 miles as the crow flies (or 1300 km for you metric types)

Banggai Islands => Bali - 570 miles direct or 900 km.

Fish are also routinely caught in Irian Jaya which is a whopping 1150 miles from Bali.

If your going to include one fish per square kilometer as collection sites .........then yes 11% of the world reefs have collection........But only 1% of the worlds reefs have collection greater then one fish per square kilometer per week...........If there was one fish collected in the Acention islands this would fit {YOUR} conditions for "hobby collection" But if we limit "hobby collection " to mean collection levels greater then that of one grouper{ one fish per square kilometer} We would find either the areas of hobby collection to be very small in number or the number of fish removed per reef to be three fish per square MILE! :lol: So if your numbersare true.........then how could removing three fish per square mile ,per week effect Larval numbers :wink:

Where did the one to three fish per square kilometre come from?

My calculation was based on 6 million fish from the Phils exported annually (E. Wood). 12,500 km2 as estimated reef area subject to collection (my estimate assuming 25,000 km2 with 50% exploitation..

This equates to 350 fish per km2 per year. The question is whether this is sustainable?

Let’s assume that 15% of these 350 fish are clownfish (based on data from exporters) – that would mean 53 clownfish per km2 per year from the Philippines.

Now I don’t have data on clownfish densities in the Philippines and Indonesia. I did however find data on clownfish densities on the Great Barrier Reef collected across 15 reefs up and down the length, inshore and offshore, by the highly reputable Australian Institute of Marine Science (www.aims.gov.au). Their data suggest that the average density of Amphiprion species (all clownfish combined) on the GBR is approximately 2000 fish per km2. Now, based on my professional experience in the Philippines and Indonesia, I’d say that the abundance of fish in these countries is WELL below that seen on the Great Barrier Reef, where the aquarium fishery is heavily managed and there are a number of no-take sanctuary zones. I’d say that the abundance in the Phils is less than 25% of Australia but let’s be generous and put it between 25% and 50%.

That means in the Philippines that we are taking 53 fish per km2 per year from a standing stock of 500-1000 fish per km2. This translates to a fishing mortality of between 5 and 10% per year.

That sounds pretty small. But consider this – fisheries scientists have been aiming for a fishing mortality of 5% with standard food fisheries such as north atlantic herring etc. Herring are a fast growing, quick to reproduce that should be able to withstand relatively heavy fishing pressure. Yet what fisheries scientists have found is that aiming for a 5% fishing mortality for herring was too high. As it has been for cod and the other 25% of the world’s fisheries that are over exploited (www.fao.org).

So why would we think that clownfish can handle 5% fishing mortality per year. They have highly structured social behaviour (pairing), low reproductive output (500-2000 eggs per batch), are not particularly fast growing. All these characteristics make them vulnerable to overexploitation. Throw in the stress associated with major habitat damage due to nutrient runoff, dynamite and yes, cyanide, and we should be considering lowering fishing mortality to less than 1% IMHO.

Thus, if you want to talk "sustainability" exploitation levels should be cut to aim for 1% fishing mortality. This would equate to between 5 and 10 clownfish per km2 per year and 50 fish per km2 total rather than 350 fish. Pretty drastic huh?

Blue hula

 

[Anemone]

Why not challenge my math? ...

The country of Fiji is a group of about 1200 individual islands............... of these 1200 islands, fish collection for this hobby takes place on only five or so{and live rock on only one island!}{one out of 1200!} There is no way that collecting {even over collecting} can have any effect on the remaining 750 islands of Fiji............

Hmmm, 1200 - "five or so" = 750.

Interesting math indeed......

Kevin

 

[blue_hula]

Why not challenge my math? ...

The country of Fiji is a group of about 1200 individual islands............... of these 1200 islands, fish collection for this hobby takes place on only five or so{and live rock on only one island!}{one out of 1200!} There is no way that collecting {even over collecting} can have any effect on the remaining 750 islands of Fiji............

Hmmm, 1200 - "five or so" = 750.

Interesting math indeed......

Kevin

Gosh that was nice and to the point. I too will try and be a bit more succinct :wink:

Blue hula

 

[mkirda]

Gosh that was nice and to the point. I too will try and be a bit more succinct :wink:

Blue hula

LOL. Don't worry about it, Blue Hula.
Those two posts were about as informative as I have seen on this forum.

I would have to concur about the fish densities in the Philippines.
There is at least an order of magnitude difference between what I saw in various areas in the Philippines vs. Tukang Besi or Wakatobi... PI cannot even compare. And from what I have heard from Gregor Hodgson, Tukang Besi is a wasteland compared to some of the last truly pristine reefs.

Difficult to imagine that many fish...

Regards.
Mike Kirda

 

[Kalkbreath]

Lets see............where to begin? First, keep in mind that many of the collection areas in both the Philippines and Indo. {that hobby fish are collected} are not included in the total square miles of reef...........like lagoons and beach fronts..........so collection ares are actually twice as great or more as your 12,500 total collection coverage.......In fact it is most likely that half of the fish are not taken from actual reefs at all ......Damsels for example make up the top five collected fish .yet virtually none are taken from theactual reefs?..Second the 2000boxes a week , number is from LAX landings (80% of all PI exports)..............That 6,000,000...fish count from the WOODS report is in line with MY personal estimate ......as 2000 boxes with forty fish per box is 80,000 .........80,000x50 weeks equals 4 million?......Also notice that in the Woods report .........she has quite a lot of difficulty finding any collection areas with decimated fishing populations even after she has been tracking the collection areas for some twenty years!? Truth is that only the collection areas in which seafood collectors blast the reefs with juice.do the fish populations have a noticeable decline.......... Its not the hobby collectors, its the indiscriminate food fishermen that harm the reefs.....with their tremendously high levels of cyanide..............Lastly Lets assume you 354 total fish per km2 is correct ..........and that the 53clownfish per km2 is true...................ONE GROUPER EATS MORE FISH THEN THIS A YEAR!. :winkoes this hobby equal one grouper in fish intake? If so lets kill that grouper.............and the reefs are saved! :roll:

 

[blue_hula]

Lets see............where to begin? First, keep in mind that many of the collection areas in both the Philippines and Indo. {that hobby fish are collected} are not included in the total square miles of reef...........like lagoons and beach fronts..........so collection ares are actually twice as great or more as your 12,500 total collection coverage.......In fact it is most likely that half of the fish are not taken from actual reefs at all ......Damsels for example make up the top five collected fish .yet virtually none are taken from theactual reefs?..

I rechecked the estimate of reef areas from Reefbase. They indicate that reef flats are sometimes in / sometimes not depending on the source of the data. Because the Philippines data was from satellite, they will likely have much of hte shallow reefy areas included. Where they indicate they have more problems is discerning how deep the reefs go but for these shallow water species you refer to, this shouldn't make a difference.

On to the damsels. I checked Fishbase (www.fishbase.org) an excellent database that pulls together all the published literature on all fish globablly (see below for details). It includes habitat data for species where this is known. Of the 6 species of damsels in John's top ten (thanks for that mate), all are associated to varying degrees with corals / coral reefs. Only one is id'd as associated partly with rubble and 3 very clearly are associated with "thickets" of coral and "coral-rich" areas. These areas would have been picked up by the Reefbase mapping. None were associated with beachfronts - all would be collected from coral areas.

Here they are, directly quoted from Fishbase. The italics are mine.

Chromis viridis: Found in large aggregations above thickets of branching Acropora corals in sheltered areas such as subtidal reef flats and lagoons.

Chrysiptera cyanea: Found amongst rubble and coral of clear sheltered lagoons and reef flats

C. parasema: Inhabits coral-rich areas of sheltered lagoon and inshore coral reefs

Dascyllus araunua: inhabits shallow lagoon and subtidal reef flats. Forms large aggregations above staghorn Acropora thickets or in smaller groups above isolated coral heads.

D. trimaculatus Inhabits coral and rocky reefs, juveniles often commensal with large sea anemones, sea urchins, or small coral heads (Ref. 4391). Occurs in small to large aggregations.

D. melanurus Schooling species, inhabits sheltered lagoons, harbors and inlets. Often associated with small coral heads.

Second the 2000boxes a week , number is from LAX landings (80% of all PI exports)..............That 6,000,000...fish count from the WOODS report is in line with MY personal estimate ......as 2000 boxes with forty fish per box is 80,000 .........80,000x50 weeks equals 4 million?......Also notice that in the Woods report .........she has quite a lot of difficulty finding any collection areas with decimated fishing populations even after she has been tracking the collection areas for some twenty years!?

To quote Liz Wood: "In conclusion, there is currently no evidence of any species collected for the marine ornamental trade being at risk of global extinction, but there is evidence of local depletions". She goes on to say that continued depletion is serious particularly for species with narrow distributions or that are naturally rare (seahorses jump to mind again).

And while Liz has been looking at the trade for 20 years as you say, the problem remains that she / we have very little biological information on most of these species let alone abundance over time in the wild. She does refer repeatedly to anecdotal evidence of declines but hey, the exporters say it's all fine. Ignorance is bliss and we can happily maintain that no data exist to show declines. What's that old quote about Rome burning while Nero twiddled his thumbs?

Or should that be sticking his head in the old araganite?

Lastly Lets assume you 354 total fish per km2 is correct ..........and that the 53clownfish per km2 is true...................ONE GROUPER EATS MORE FISH THEN THIS A YEAR!. :winkoes this hobby equal one grouper in fish intake? If so lets kill that grouper.............and the reefs are saved! :roll:

The grouper is already dead. He was caught for a dentist's fish tank.

Why is it so difficult to understand that the issue is one of CUMULATIVE pressures? The reason we should keep fishing mortality low (e.g. below 5%) is because these animals face a host of other pressures (habitat degradation, predation, etc.). Local depletions are a bad thing for the ecological health of reef communities. We should be doing our best to ensure that we are not contributing to this, regardless of what buddy next door is doing.

Blue hula

 

[PeterIMA]

I agree that the published data concerning fish densities on Philippine coral reefs is generally lacking except in a few areas like Bolinao (studied by Dr. McManus and students from the University of the Philippines. But, the degree of reef degredation is real and there have been documented declines in fish abundance both from the commercial food fisheries and the aquarium fisheries. I suggest you get a copy of "The Values of Philippine Coastal Resources: Why Protection and Management Are Critical: by Dr. Alan White and Annabelle Cruz-Trinidad published by the Coasta Resource Management Project of the Dept of the Environment and Natural Resources (DENR) and the U.S. Agency for International Development (USAID) in 1998.

I estimated the numbers of marine aquarium fishes being exported in 1995 from the Philippines at about 6 million fish (based on IMA's monitoring of the numbers of boxes and averaged estimates on fish weights. 1995 was higher in total numbers of boxes exported than earlier and later years. So, I doubt that 6 million aquarium fish are presently being exported annually now. Can Kalk substantiate the 2,000 boxes a week entering the USA as being just from the Philippines, and not also from Indonesia? I would agree with John Tullock's and Elizabeth Wood's estimates that the numbers of marine aquarium fishes entering the USA is about 10 million fish (from all exporting countries).

I disagree with Kalk's claims that these fish come from only a few coral reefs. My information indicates that most reefs in the Philippines and in Indonesia are being exploited (as indicated also by Blue Hula). The Philippine coral reefs are being subjected to intense exploitation and are already overfished. Other than the ICLARM study in Bolinao there does not appear to be many estimates of fishing motality for aquarium fishes harvested from Philippine coral reefs. It is unlikely that there ever will be quantitative surveys long-term surveys conducted to provide this type of information. I believe that the reefs can withstand rates of exploitation of up to 15% (based on my experience with stock assessments in Canada).

Underwater surveys similar to the ones done along line transects by Ferdinand Cruz with fish collectors in the Philippines (e.g. CAMP reports for MAC in Palauig and Busuanga) are feasible and can be used to determine in general terms whether the reefs are overexploited or not. The methods used are simple means to rapidly determine fish densities and fish species composition (both food fish and aquarium fishes). MACTRAQ could be used but is probably too costly; since it would need to be done by professional biologists and analyzed by statisticians.

Kalk's arguements are mostly speculative. Enough data exists to support the contention that Philippine coral reefs are overexploited, heavily degraded, and need of protection and conservation measures. Actions are needed NOW.

Peter Rubec

 

[Kalkbreath]

Once again neither of you have demonstraighted that this hobby is responsible for the few areas in which reefs are somewhat comprimised......Yes, damsels live in the coral........but almost no collectors fish in the coral for damsels.....only in rock and coral rubble zones ........almost all of the top twenty fish are collected in non reef in eviroments. Clownfish ,damsels cromis gobies blennies{dart fish} are all collected in the rock zones {no not all ,but 90%} Yes, some fish are collected in the farr off islands {blue faces} but 80% of the fish are collected within 100 miles of of the two big airports..........Steve Knows this and so does Cruz....{funny how they stay away when they know im correct?} .............................................................. If all 6 million fish are collected fron half thetotal islands in PI...12,000 KM2 ......... this means only 350 fish are collected per square kilometer!!! From a fish density of several MILLION per square kilometer!!!!!

 

[Kalkbreath]

I estimated the numbers of marine aquarium fishes being exported in 1995 from the Philippines at about 6 million fish (based on IMA's monitoring of the numbers of boxes and averaged estimates on fish weights. 1995 was higher in total numbers of boxes exported than earlier and later years. So, I doubt that 6 million aquarium fish are presently being exported annually now. Can Kalk substantiate the 2,000 boxes a week entering the USA as being just from the Philippines, and not also from Indonesia? I would agree with John Tullock's and Elizabeth Wood's estimates that the numbers of marine aquarium fishes entering the USA is about 10 million fish (from all exporting countries).There are LESS then 2,000 boxes comming in per week

I disagree with Kalk's claims that these fish come from only a few coral reefs. there does not appear to be many estimates of fishing motality for aquarium fishes harvested from Philippine coral reefs. It is unlikely that there ever will be quantitative surveys long-term surveys conducted to provide this type of information. I believe that the reefs can withstand rates of exploitation of up to 15% (based on my experience with stock assessments in Canada).




Peter Rubec

Then problem solved= 350 fish out of a few million IS much Less then 15% How many total aquarium fish are there in the waters of PI? ..........6 million fish per year {actually less} is so tiny ............even if we double it to account for 50% mortality............ There are more fish in ONE square Kilometer then 6 miilion on some reefs!! so that translates into 1/ 12,000 th or one onehunredth of one percent? And you thought my ONE percent was too low :wink:...........................................{ 1/100th of one percent of the wild fish populations in PI are collected each year}THIS IS YOUR DATA

 

[PeterIMA]

Kalk, I don't follow your math. What does the 350 fish represent? Please provide estimates of the numbers of fish (by species) per meter square (or per hectare) on degraded coral reefs. Hint, start with a figure of 5 mt per square kilometer per year as a yield for everything (food and aquarium fishes) from degraded coral reefs. Please provide information on what reefs are still commercially exploitable (very few). Estimate the area of healthy reefs (less than 3% of the total area listed by Blue Hula). Use a yield of 20 mt per sq kilometer per year for healthy reefs in good to excellent condition (represents all exploitable species). Factor in about 50% mortality on the reef for cyanide use, and another 30% at the collector level and 30% at exporters' facilities. Then use a figure of 6 million (or less) survivors.

If you need further information for your assignment go to FishBase (like Blue Hula). Factor in habitat destruction and the mortalities from cyanide collection before you provide mean densities per square meter. Extrapolate the numbers per square meter or per sq kilometer from the literature to estimate population numbers by species in the healthy areas. Then calculate how many fish there would be by species (population number estimates) in the healthy areas. Then estimate by species what 15% or that number represents.

Please post your calculations so we can evaluate them.

Peter Rubec

 

[Kalkbreath]

Peter ,if your not following along in the tread.......then dont jump in......Blue_hula {is that php /} came up with the 350 fish per kilo ten posts ago.........He took the total of 6 million and divided it by the total square kilos of collection areas{which is what you should have done years ago}.......this simple math shows that the hobby , even from the most heavily collected country , this hobby collects 350 fish per square kilometer.........Wow thats not much ? wonder what all the fuss is about? Peter, how many fish per km2 in the Philippines? What percentage is 350 of that total? YES........... you can double it if you like, and it still end up squat {less then one percent}:wink: I know , "its the combined stresses on the reefs" Funny that one or two groupers can eat more then this hobby collects? Yet its our "unsustainable collection" that "harms the reefs"? Ferdi , how many of the top ten collected fish are even collected within the reefs themselves{as apposed to the rock and rubble zones}?Steve , how many of the top ten collected species can you even collect with cyanide? You have stated many times on this forum that mandarins damsels and gobies "CANT " be taken with juice" {its because they fall over dead with even the smallest dose} Seems the more we learn, the more the truth is painting a picture of deception and false accusations about this hobby ......... 8) Next batter please-> :twisted:

 

[PeterIMA]

Kalk,
Again, you oversimplify. Thanks however for explaining how Blue Hula derived the 350 fish per square kilometer figure. It was a good starting point. Apparently, she has quite credible scientific credentials. So have I.

My previous posting indicated that most of the aquarium fishes come from reefs that are in good to excellent condition. The densities on the degraded reefs is much less (e.g., reefs in good to excellent condition have yields of 20 to 37 mt/sq. km/yr while degraded reefs have yields of less than 5 mt/sq. km/yr). Taking this analogy further, if a healthy reef can produce 10,000 fish a degraded reef may support only 500 fish (figure obtained from McManus report concerning the coral reef off Santiago Island near Bolinao). Basically, I am saying that the extrapolation of a mean density of fishes of 350 is probably wrong. Most coral reefs in the Philippines support much less under their present degraded state. Perhaps 3% of the reefs support high densities of fishes. These remaining reefs are being targeted by collectors, the majority of whom still use cyanide as a collecting tool.

Without a detailed analysis using GIS that takes into account the different reef zonations (determined by remote sensing) and an attempt to tie the status (health/condition) of the reefs to these areas (could use data from underwater surveys conducted by Dr. Edgardo Gomez of University of the Philippines) I don't put too much credance in the 350 fish per sq. km estimate derived by Blue Hula (despite her impressive credentials and experience in the Philippines).

However, it is your spin on these matters with which I totally disagree.

Peter Rubec, Ph.D.
Research Scientist- Florida Fish and Wildlife Conservation Commission
(presently conducting fish habitat suitability modeling using GIS)

 

[John_Brandt]

Kalk,
Again, you oversimplify. Thanks however for explaining how Blue Hula derived the 350 fish per square kilometer figure. It was a good starting point. Apparently, she has quite credible scientific credentials. So have I.

Without a detailed analysis using GIS that takes into account the different reef zonations (determined by remote sensing) and an attempt to tie the status (health/condition) of the reefs to these areas (could use data from underwater surveys conducted by Dr. Edgardo Gomez of University of the Philippines) I don't put too much credance in the 350 fish per sq. km estimate derived by Blue Hula (despite her impressive credentials and experience in the Philippines).

Peter,

I don't recall blue hula ever making a self-reference to gender.