Fuzzy numbers?

[dizzy]

Peter,
I made the fatal error of trying to explain to Hy, what I thought kalk meant. I agree that fish probably die in hobbyist tanks from cyanide related problems. I don't know if the percentages are correct or not, but 95% seems high. Maybe that wasn't even what kalk was referring too. Even if all the fish caught from cyanide died prior to reaching hobbyists tanks it wouldn't make the practice of killing the corals to capture them somehow acceptable. From now on kalk can do his own explaining.

 

[hdtran]

Dizzy,

It's not a fatal error. You're still alive, right? :lol: Your computer hasn't suddenly gotten the dreaded blue screen of death? Your tank doesn't suddenly have a family of mantis shrimp, aiptasia, and xenias fighting it out with zoanthids? 8) (oh, and I forgot--a school of damsel!)

But please do let Kalk try to explain in words that I can understand. I have a very hard time understanding him; I don't know if it's just me (non-native speaker of English here), him, or some combination.

Regards,

Hy

 

[Kalkbreath]

Its not that hard to follow, Peters data for the five years concluded that 75% of the fish in the supply are "clean". So now we have to shave off another fifteen percent of Peters data to arrive at 90%. {which is what I conclude} Sixty percent of the fish exported from Pi are Damsels. Damsels , during the last three years of Peters testing showed 10% positive for cyanide. Because 60% of the three million fish exported are testing at 10 % and the remaining forty percent are at 25%.......................... that pulls the actual percent of the total fish down to about 80% to 90% CLEAN!. See, Peter did not sample the fish in the ratios that are being collected in the real world. Of the twelve million fish imported to the USA, fifty percent are damsels. But , in the Philippines sixty to seventy percent of the total fish collected are damsels . Slightly more then the other collection countries, because PI is the tiny fish king. No other country can ship damsels as cheaply as PI. The cheaper Airfreight and cheaper labor has kept other countries from competing .....for sales of cheap fish like damsels {about twenty cents in PI but one to two dollars from fiji or Tonga}

 

[hdtran]

Sixty percent of the fish exported from Pi are Damsels. Damsels , during the last three years of Peters testing showed 10% positive for cyanide

(by the way, please chastise me if I'm quoting out of context).

Rubec, Pratt, McCullough, et al. (2002). (Too lazy to type a formal citation, sorry...)

Table 3-B, 1996-1999 data (can't find 2000-2003, when Kalk writes "the last three years" I assume he means the last three years reported here). I find the line for Pomacentridae, which is chromis, damsel, clown. I see 1807 fish tested, 345 with cyanide ion detected. That's 19%?

Help me out here. I can't find 10%. What am I missing?

 

[mkirda]

Help me out here. I can't find 10%. What am I missing?

Math Kalk-style?

 

[Kalkbreath]

Sixty percent of the fish exported from Pi are Damsels. Damsels , during the last three years of Peters testing showed 10% positive for cyanide

(by the way, please chastise me if I'm quoting out of context).

Rubec, Pratt, McCullough, et al. (2002). (Too lazy to type a formal citation, sorry...)

Table 3-B, 1996-1999 data (can't find 2000-2003, when Kalk writes "the last three years" I assume he means the last three years reported here). I find the line for Pomacentridae, which is chromis, damsel, clown. I see 1807 fish tested, 345 with cyanide ion detected. That's 19%?

Help me out here. I can't find 10%. What am I missing?

Thats because Peter wont release the data. BUT , If the average for damsels was 16 percent for all five years. the average for the three most current years would be less then 16%. I am estimating 10%{.....it might be five percent? Damsels are easy to catch and there has never been a shortage of them despite the huge collection numbers for twenty years. If the ten percent is correct......... then sixty percent of the fish leaving PI are have only a one in ten rate of cyanide exposer. Even Peters 25% for all species means that 75% of the fish leaving the Philippines have not been exposed to cyanide. Then account for the fact that Peter states that cyanide collected fish have a higher DOA rate and that means that at retail some of those twenty-five percent cyanide exposed fish have died before reaching the retailer and in turn the hobbyist. So the chances of a hobbyist actually buying a cyanide exposed fish from PI is even less then the testing results.So in the real world , only ten to fifteen percent of the fish leaving PI have been exposed to cyanide. In part because most of the fish being exported are not commonly collected with cyanide.{confirmed in peters data} then the fact that most of the fish that are collected with cyanide never reach the consumer because they die along the chain of custody. {also confirmed by Peter....ie 30% here 30% there etc.}

 

[hdtran]

Kalk (a couple of posts back)

Damsels , during the last three years of Peters testing showed 10% positive for cyanide.

Most recent post here

If the average for damsels was 16 percent for all five years. the average for the three most current years would be less then 16%. I am estimating 10%

Hy (am I allowed to quote myself?)

I see [Rubec et al.(2002)] 1807 fish tested, 345 with cyanide ion detected. That's 19%?

I'm willing to stipulate that 1996-1999 is 4 years, not 3, or 3 years, not 4. (Depending on how you count, where you start counting from, etc., you can get a fencepost error). But I guess I'm not willing to stipulate an estimate going from 19% (average from 1996-1999) to 10% without seeing any numbers. I'm willing to accept your arguments that the %clean coming into the US is higher than %clean tested, because of (a) death in transports, and (b) proportion exported to US is different than proportions tested, but until I see actual numbers stating % loss on transport and (b) % proportions exported, I will still say that your (paraphrasing here) "80-90% net caught" doesn't hold water.

Regardless of the exact numbers, even accepting your hypothesis of 1.8 million Filipino Pomacentridae and 10% not-net-caught, that's 180,000 cyanide-caught Pomacentridae, which is a frightening number. (BTW, I'm not agreeing that it's 10%, I'm just saying that if I were to do so, along with 60% of 3 million, I'd come up with 180,000 cyanide-caught damsels)

Until then, back to lurking!

Kalk, thanks for your patience going thru your arguments for me (and taking most of the ....'s out of your posts). Greatly appreciated. Peter, thanks for the preprint! Very interesting! Mike Kirda; Dizzy; thanks for your inputs, ultimately to someone who doesn't matter (I'm just an amateur here, after all :wink: )


Hy

 

[Kalkbreath]

The averages for 1998 thru 2000 was 8%, 18% and 29% respectively. Thats 15% for all species during those years. Damsels being so esy to collect and plentiful makes it seem that they would be below the average of 15%. Yes 10% is not a great number for cyanide collected fish. But , expecting better then ten percent from a country like PI is more then likely a dream. Even here in the USA..........then percentage of every motorist on the hiways are breaking the law, at least Ten percent of all Americans cheat on there taxes..........Ten percent cheat on there wives .......Ten percent of Americans steal music from the Internet...........ten percent do illegal drugs ..........etc. Are we so pompous that we demand more fortha Philippines then we demand at home?

 

[mkirda]

The averages for 1998 thru 2000 was 8%, 18% and 29% respectively. Thats 15% for all species during those years.

15%??? Now that is "fuzzy math"...

8 + 18 + 29 = 55

55/3 = 18.33, not 15.

We've already gone through any number of simple reasons why these numbers are actually likely to be low. I've yet to see a single coherent reason why they should be high.

Regards.
Mike Kirda

 

[hdtran]

Can't resist...

Let's accept, for the moment, 8% cyanide collected in 1998, 18% in 1999, 29% in 2000.

That's an increasing trend. I can do a straight linear extrapolation, and assert that in 2001 (no data reported), there would be 30% cyanide collected, 2002, 41%, 2003, 51%, 2004, 62%. Why I should I believe your assertion that in 2002-4, the percentage of cyanide collected would drop down to 10%? Unless one has a model in mind, one should not extrapolate from a data set. So, I still am not convinced of the "only 10% of the Pomacentridae coming into the US from the Phillipines are cyanide collected" (paraphrase here, not direct quote).

Second argument: Crime is everywhere, 10% level, pompous do-gooding Americans, etc. This is fallacious, as you take no account of the severity of the act. If one were to carry your argument to its logical extreme, one would have to find it acceptable to have 10% of all drivers on the highway to be inebriated? Please, no. I'm more than happy to accept 10% of drivers speeding 10% above the speed limit, but would advocate throwing any driver with a detectable blood alcohol level in jail. (Yes, I know the law says .08%, but my opinion on this is more draconian).

Thanks for hearing me out!

(Back to lurking. Really!).

p.s. Edit done, because Mike Kirda posted while I was replying. Maybe Kalkbreath did a weighted average, based on the numbers tested in 1998, 1999, and 2000. Then again, maybe not, since he did not put down details of his calculations. Or perhaps you want to chip in and buy him a calculator?

p.p.s. Final edit (really!!): Quoting myself (sort of), regardless of the exact numbers (I'm willing to live with the numbers being off by 10% or even 20%, so if someone reports 15%, I'd be willing to accept a 3-sigma uncertainty between 12% and 18%)--The sheer total number which would be collected using damaging means (e.g. blast, cyanide) still horrify me.

 

[Kalkbreath]

The averages for 1998 thru 2000 was 8%, 18% and 29% respectively. Thats 15% for all species during those years.

15%??? Now that is "fuzzy math"...

8 + 18 + 29 = 55

55/3 = 18.33, not 15.

We've already gone through any number of simple reasons why these numbers are actually likely to be low. I've yet to see a single coherent reason why they should be high.

Regards.
Mike Kirda

whoops your right , There is somewhere on these threads that Peter miss typed 8% -8% and 29 % Thats why I have the fifteen in My head.

 

[Kalkbreath]

Can't resist...

Let's accept, for the moment, 8% cyanide collected in 1998, 18% in 1999, 29% in 2000.

That's an increasing trend. I can do a straight linear extrapolation, and assert that in 2001 (no data reported), there would be 30% cyanide collected, 2002, 41%, 2003, 51%, 2004, 62%. Why I should I believe your assertion that in 2002-4, the percentage of cyanide collected would drop down to 10%? Unless one has a model in mind, one should not extrapolate from a data set. So, I still am not convinced of the "only 10% of the Pomacentridae coming into the US from the Phillipines are cyanide collected" (paraphrase here, not direct quote).

Second argument: Crime is everywhere, 10% level, pompous do-gooding Americans, etc. This is fallacious, as you take no account of the severity of the act. If one were to carry your argument to its logical extreme, one would have to find it acceptable to have 10% of all drivers on the highway to be inebriated? Please, no. I'm more than happy to accept 10% of drivers speeding 10% above the speed limit, but would advocate throwing any driver with a detectable blood alcohol level in jail. (Yes, I know the law says .08%, but my opinion on this is more draconian).

Thanks for hearing me out!

(Back to lurking. Really!).

p.s. Edit done, because Mike Kirda posted while I was replying. Maybe Kalkbreath did a weighted average, based on the numbers tested in 1998, 1999, and 2000. Then again, maybe not, since he did not put down details of his calculations. Or perhaps you want to chip in and buy him a calculator?

p.p.s. Final edit (really!!): Quoting myself (sort of), regardless of the exact numbers (I'm willing to live with the numbers being off by 10% or even 20%, so if someone reports 15%, I'd be willing to accept a 3-sigma uncertainty between 12% and 18%)--The sheer total number which would be collected using damaging means (e.g. blast, cyanide) still horrify me.

Please read Peters study {the link is on the first page}Keep in mind that the cyanide numbers for the early 1990s was 65% and 80%! The reason Peter gave for the decrease in 1998 was that an increase in anti cyanide awareness was curbing the use out on the reefs. Today in 2004 the awareness has never been greater. Even the local newspapers are talking about stopping cyanide use. There is also much greater competition from other countries. Places like Srilanka , Bali and Vietnam are forcing PI collectors to compete. Thi s combined with MAC breathing dowmn the backs of collectors ......it seems to reason that cyanide use might be at an all time low.... ten percent of 3 million is a large number.......but there are 25,000 square kilometers of reef we collect from in PI. thats only ten or so fish per year collected with cyanide every square mile . Even mother nature "Naturally " destroys a hundred times that each year on average. We in American clear cut 65000 acres each day to build on . Do you think Mother nature can keep up with our rate of habitat destruction? Many scientists consider ornamental collection as having zero effect on the reefs .......its the food fish industry they fear........here is an interesting study that even demonstrates how blast fishing over shadows cyanide food fish collection!

Abstract
According to three precautionary estimations, the reef-degrading capacity of the cyanide fishery for food
fish on Indonesia’s coral reefs amounts to a loss of live coral cover of 0.047, 0.052 and 0.060 m 2 per 100 m 2
of reef per year. These estimates for the rate of coral cover loss are low compared to published rates of nat-ural
coral recovery. Differences in growth rate between species of hard coral will cause coral reefs to take
longer to recover from the effects of cyanide fishing than a direct comparison of the rate of coral cover loss
with published rates of natural coral recovery would suggest. Still, the cyanide fishery for food fish may
not be as threatening to Indonesia’s coral reefs as is sometimes assumed, especially not as compared to
other threats such as blast fishing (responsible for a loss of live coral cover amounting to 3.75 m 2 per 100 m 2
of reef per year, (Pet-Soede, Cesar & Pet, 1999)), or coral bleaching caused by global climate change (cf.
Hoegh–Guldberg, 1999). Setting the input variables for the estimates at extreme values did not change
these conclusions substantively. The depletion of grouper stocks by the trade in live reef food fish, how-ever,
is worrying from both fisheries and conservation perspectives. Strategies to abate the depletion of
these grouper stocks should not only consider cyanide fishing, but also other fishing methods.
Cyanide fishing on Indonesian coral reefs for
the live food fish market – What is the problem?
Peter J. Mous 1 , Lida Pet-Soede 2 , Mark Erdmann 3 ,
Herman S.J. Cesar 4 ,Yvonne Sadovy 5 & Jos S. Pet 6

http://websearch.cs.com/cs/boomframe.jsp?query=Mous+P%2CPet-Soede+L%2CErdmann+M%2CCesar+H%2CSadovy+Y%2CPet+J+%282000%29&page=1&offset=0&result_url=redir%3Fsrc%3Dwebsearch%26amp%3BrequestId%3D4841400c9b5f9664%26amp%3BclickedItemRank%3D4%26amp%3BuserQuery%3DMous%2BP%252CPet-Soede%2BL%252CErdmann%2BM%252CCesar%2BH%252CSadovy%2BY%252CPet%2BJ%2B%25282000%2529%26amp%3BclickedItemURN%3Dhttp%253A%252F%252Fwww.komodonationalpark.org%252Fdownloads%252FMous%252520et%252520al%2525202000.pdf%26amp%3BinvocationType%3D-%26amp%3BfromPage%3DCSroll&remove_url=http%3A%2F%2Fwww.komodonationalpark.org%2Fdownloads%2FMous%252520et%252520al%2525202000.

 

[Anonymous]

what is your point kalk?

(i've actually been wondering for a long time)

 

[Kalkbreath]

The point is that there is very little evidence that our hobby is having an impact.Even what we have thought was evidence seems to be little more then sound bites. Yet the message that our hobby is killing reefs is being played loader and more often [most often by people that directly benefit from falsely denigrating the industry}......Kinda like Kent Marine making false claims against Seachem just to boost their stronghold........Its just not right! And all this hype may be having an impact on the number of people entering the hobby and may falsely persuade governments to end the trade. We need more hobbyists ... only with more reef consumers can there be enough money to properly reeform the collection industry and increase the total dollars spent on Aqua culture. Not until the reef hobby has enough total purchasing power can we as an industry reeform air freight and thus decrease the time and stress on the livestock. Not until the hobby has enough influence to tward of food fishing on the reefs can the reefs really be saved. Not until the majority of Americans have seen first hand and experienced the wonder of "captive" reefs .......will the majority of Americans care enough about the wild reefs to bring about change......We as a hobby cant help the reefs directly ........We can only use our hobby to influence as many people as possible. Painting our hobbyists as a group of reef rapists ..will not do much in the way of the b welcoming us to teach them about the need to save the wonders of the reefs.............. . The truth is the truth.......Find it and only then can any real solutions be found. :wink:

 

[Kalkbreath]

double

 

[Kalkbreath]

triple

 

[hdtran]

Kalk,

Most excellent citation (Mous P.J., Pet-Soede C., Erdmann M., Cesar H.S.J., Sadovy Y., & Pet J.S., 2000. Cyanide fishing on Indonesian coral reefs for the live food fish market – what is the problem? Secretariat of the Pacific Community Live Reef Fish Information Bulletin 7, 20-27. (pdf; 76 Kb) Also appeared in: H.S.J. Cesar (ed.) 2000. Collected essays on the economics of Coral Reefs. CORDIO, Dept. of Biology and Environmental Sciences, Kalmar University, Kalmar, Sweden. pp 69-76.)

Web publication downloadable as a PDF from http://www.komodonationalpark.org/downl ... 202000.pdf

(Not sure that the link will be 'live').

Excerpting from the article:

The damage done by the cyanide fishery for the much smaller sized, ornamental fish is probably much greater than that for food fish, as the number of target fish per unit of reef area is much higher. Also, mechanical reef destruction in the fishery for ornamental fishes may be more extensive, as branching corals are broken apart over large areas, in order to retrieve the small fish (pers. observ.). A relatively high estimate of reef loss inflicted by the fishery for ornamental fish (0.4% reef loss per year) was also suggested by McManus, Reyes & Nanola (1997).

and

...Mortality in non-target fishes caused by cyanide fishing is even more difficult to quantify. Because of their higher metabolic rate per unit of body weight, smaller fish that were in the direct vicinity of the target fish at the moment of capture most probably die. The mortality probably depends on the rate of dilution of the squirted cyanide, and on the amount of fish that were in the direct vicinity of the target fish. This unknown collateral damage is one of the reasons why we think that cyanide fishing should not be tolerated.

Quoting Kalkbreath, now:

Many scientists consider ornamental collection as having zero effect on the reefs .......its the food fish industry they fear

Quoting from the very interesting article Kalk pointed me to (just repeating quote above) The damage done by the cyanide fishery for the much smaller sized, ornamental fish is probably much greater than that for food fish, as the number of target fish per unit of reef area is much higher

Thanks for pointing out the article to me! I'm not familiar with the literature in fish collection ecology, so this is a treat! (Now, if you want citations on, say, compensation of laser interferometers, I'd be happy to point you the right way :wink: )

 

[Kalkbreath]

Kalk,

The damage done by the cyanide fishery for the much smaller sized, ornamental fish is probably much greater than that for food fish, as the number of target fish per unit of reef area is much higher. Also, mechanical reef destruction in the fishery for ornamental fishes may be more extensive, as branching corals are broken apart over large areas, in order to retrieve the small fish (pers. observ.). A relatively high estimate of reef loss inflicted by the fishery for ornamental fish (0.4% reef loss per year) was also suggested by McManus, Reyes & Nanola (1997).

Yes , The number of hits on a reef being fished by MO juice fishermen will be more numerous......but the concentration of cyanide used by food fish collectors is much more intense {being that it takes more cyanide to knock out a five pound grouper then a three ounce blue tang. Food fish are collected at a rate of two thousand pounds per square kilometer per year ........yet pet fish only at the rate of 120 fish per square kilometer! Thats about five hundred to one ! When Damsels and Blue tangs are collected with cyanide they are usually collected in multiples....that is the whole school at at time {ten to twenty} But fish like food groupers ....One at a time.Yes , the net collectors whom crowbar the live coral to get to the hiding fishes , do much more harm then cyanide collectors. When the coral is laying at the bottom of the reef , there is no place for new coral recruitment's

and

...Mortality in non-target fishes caused by cyanide fishing is even more difficult to quantify. Because of their higher metabolic rate per unit of body weight, smaller fish that were in the direct vicinity of the target fish at the moment of capture most probably die. The mortality probably depends on the rate of dilution of the squirted cyanide, and on the amount of fish that were in the direct vicinity of the target fish. This unknown collateral damage is one of the reasons why we think that cyanide fishing should not be tolerated.

This is precisely why when food fishermen fish with high doses of cyanide they create a plume of death that is quite large.......hobby collectors fish with cyanide levels that dont kill the targeted fish outright.......there is no sense in going after a blueface angle only to over stun and kill it . The majority of Food fish collectors dont care if their target dies .......its going to die after they throw it into the boat .......!

 

[Kalkbreath]

OK I gota know .....what does a laser interferometers......do?

 

[Anonymous]

The point is that there is very little evidence that our hobby is having an impact.Even what we have thought was evidence seems to be little more then sound bites. Yet the message that our hobby is killing reefs is being played loader and more often [most often by people that directly benefit from falsely denigrating the industry}......Kinda like Kent Marine making false claims against Seachem just to boost their stronghold........Its just not right! And all this hype may be having an impact on the number of people entering the hobby and may falsely persuade governments to end the trade. We need more hobbyists ... only with more reef consumers can there be enough money to properly reeform the collection industry and increase the total dollars spent on Aqua culture. Not until the reef hobby has enough total purchasing power can we as an industry reeform air freight and thus decrease the time and stress on the livestock. Not until the hobby has enough influence to tward of food fishing on the reefs can the reefs really be saved. Not until the majority of Americans have seen first hand and experienced the wonder of "captive" reefs .......will the majority of Americans care enough about the wild reefs to bring about change......We as a hobby cant help the reefs directly ........We can only use our hobby to influence as many people as possible. Painting our hobbyists as a group of reef rapists ..will not do much in the way of the b welcoming us to teach them about the need to save the wonders of the reefs.............. . The truth is the truth.......Find it and only then can any real solutions be found. :wink:

hobbyists fund aquaculture?

seems to me the amount of aquaculture ops funded either directly, or indirectly, by hobbyists(if such a critter really exists) is a small (miniscule)fraction of aquaculture funded by private enterprise, or grants, both private, and governmental.


how do hobbyists fund aquaculture?

by 'fund' do you mean 'support through patronization'?

they aren't the same thing

The point is that there is very little evidence that our hobby is having an impact.Even what we have thought was evidence seems to be little more then sound bites

little evidence to you, i've seen more than i've ever cared to, including direct personal observation

you might wanna change that 'we' to 'i'