28 replies to this topic

[ehanauer]

I've posted my anti Shark Week video on YouTube. It's entitled "In Search of a Man Eating Shark," and was shown at the San Diego UnderSea Film Exhibition this year.

Narration and statistics state that sharks have more to fear from humans than humans from sharks.

Here's the link:

[Autopsea]

Nice work : ) I guess you could get a better voice quality from the video ? it sounds "oldish", not sure it's on purpose ?

another comment that i've previously trying to make :
This '100 millions sharks are killed by man each years' comes from nowhere, and using it makes "you", but then "us" as sharks protectors, not trustable for politics that would eventually learn the truth.
They might think "Okay these guys are just overmaking it to make their point, I'm not listening to activists anymore".

I recommend you to read this, consider what is really said here, and remember when was it done and what have been done to protect sharks since, plus how many area are not usable anymore because there is no more sharks left :

Clarke S, McAllister MK, Milner-Gulland EJ, Kirkwood GP, Michielsens CGJ et al. (2006) Global estimates of shark catches using trade records from commercial markets. Ecology Letters 9:1115-1126

saying this very friendly : )

Thomas

[ehanauer]

Since much of shark finning is illegal, I'm sure the fishermen don't report their "catch," so nobody has the real numbers. I've seen estimates ranging from 70 million to 100 million. I used the larger figure.

One is too many.

[Autopsea]

Of course one is too many, but lying, even not on purpose, on the facts doesn't help : it potentially has the opposite effect to discredit people fighting for sharks : /

Edited by Autopsea, 12 October 2012 - 07:25 AM.

[ehanauer]

If you can prove to me that the 100 million figure is false, I'll admit to lying.

[Oceanshutter]

Eric,

I agree with you. One is too many. Argueing over how massive the number doesn't stop it.

I flew down to the sdufex show for the first time and my wife and I really enjoyed. I also enjoyed your films. Congrats.

Dustin

[errbrr]

Prove to me that it's true and I'll believe the rest of your video...

It's not about lying. It's about convincing a wider audience of your message, and convincing them enough that they take action. The first step in being persuasive (and persuading people who don't want to be persuaded) is being believable beyond any shadow of doubt. It's a higher standard than the hysterical anti-shark coverage is held to, that's for sure.

Congrats on getting your video in the exhibition. I especially like the shots of the seal and the great white.

[Steve Williams]

The 100 Million number I’m familiar with appears to have come from the report; Status and Conservation of Sharks in the Mediterranean Sea, by Ameer AbdullaIUCN Global Marine Programme, Published online: October 2004In this report he states;“Every year, 100 million sharks and related species are caught in fisheries. Some species have been reduced by more than 80% over recent years, and some may become extinct before long. In 2000, FAO reports put total catches of shark at 828,364 tons. This was 20% more than in 1990. Indonesia had the largest recorded shark catch in 2000 at 111,973 ton. Spain had the second largest recorded shark catch total at 77,269 ton (FAO Fishstat). The FAO estimates that in 1997 world production of shark fins was 6 million kg. Hong Kong handles 50- 80% of the world trade in shark fins.”You can find other numbers but the source data always has the same problems. Just a couple of examples; Another more recent study I read estimates between 38 and 78 million sharks go through Hong Kong were taken annually earlier in the decade to support the fin soup industry. Untold millions more go through other Chinese ports. The Chinese govt has a duty on Shark fins so much of the true shark impact is under reported to avoid the “tax”. These numbers do not include sharks taken world wide for meat, or sharks removed from our ocean as by catch, or sharks taken that go unreported. Sadly, the estimates of sharks killed for soup are easily 3 times the documented number through Hong Kong. That gets you a number between 114 and 234 million sharks a year being taken from the world’s ocean. Whichever way you go Eric’s number is unfortunately very believable. Granted the data is almost always four or five years old as the studies seem to take far too long to publish so one can argue the data isn’t current. But the reality for me is that if the numbers are less recently it’s because the people killing the sharks have decimated the populations to the point that they are simply no longer out there to catch.I think Eric's video does a great job of getting some peoples attention, I was there and heard the electricty go through the crowd as they saw the film. And Thomas that's not "oldish" voice quality, it's experience talking. ;-)Cheers,Steve

Edited after reading the referenced report

Edited by Steve Williams, 14 October 2012 - 01:12 PM.

[Drew]

First of all, I applaud Eric's effort in making the video. Autopsea's advice on using accurate statistics unfortunately directly affects only one small aspect of Eric's video. However, it is an issue that needs addressing.

The 100 million number, as Autopsea says, is really contentious for many reasons. I believe the original "100 million" number came from Michael Lemonick's article "Under Attack"in Time. His source was apparently the "estimates" from the Audubon Society's extrapolations from FAO data. Except NOWHERE in the FAO numbers actually gives a number for sharks killed, instead it estimates weight by metric tons. Now there are many ways to extrapolate fish numbers based on weight ratio of fin vs body weight but then the type of sharks aren't detailed in many FAO countries nor are they accurately reported. I personally think the 100 million number was an oversimplified extrapolation and over-enthusiastic rounding since there was no data to support this number. And since it sounded so dramatic, it was repeated by conservationists.

Steve, Shelley Clark's numbers of 26-73 million estimate was her extrapolation of data for the global market, not just Hong Kong. However, even she has an issue with the numbers being quoted which she eloquently explains here:

http://www.seaweb.or...hellyClarke.php

So Shelley finds the numbers suspect for the reasons she stated and I agree. Autopsea's caution in using that number is fair because there really isn't any scientific basis behind it except that Audobon Society report using extrapolated numbers based on really incomplete FAO figures, conflating inaccuracy with a bit of hysteria in reporting.

So what's the big deal? After all. "over 100 million" sounds a lot more dire than "about 20-40 million" as a sound bite for the "low information" audience. However, when one has to present the science as an argument for conservation to government officials, that sort of unfounded rhetoric loses traction quickly. Anyone with any statistical knowledge will want to see the source of such claims, and there isn't any scientific basis for that number. How convincing can someone spouting unproven numbers be to people who put laws down to protect sharks?

Earlier this year, there was an open forum on the merits of shark fin soup in Singapore. The first thing shark fin advocates did was attack the lack of scientific evidence for the statistics stated by certain anti-fin advocates. That lost quite a bit of traction in getting the public support for a ban on shark fin. In fact, Shark Savers has stopped using the 100 million figure and uses "millions of sharks" to avoid this issue.

Bottom line is there is very little data, yet big numbers are being used without real basis.

Eric, if you wish for this discussion to be moved to another topic, please let me know and I'll move the posts so we don't dilute your video and its purpose. I hope you does not see this as an effort to disparage your work but as a suggestion to be more accurate.

[Steve Douglas]

Anyone ever read Stuart Chase's 'How to Lie with Statistics'? I did in '69 and never forgot it. Though some studies do not agree with eachother nor come to the same conclusions, I, never the less, have no reason to doubt Eric's research. -Steve

[Steve Williams]

The bottom line I would argue is that far far too many sharks are being taken from our ocean. The suggestion to be more accurate appears to be an impossible goal. What would you folks have the "environmentalists" use as an acceptable number? I understand the fisheries and shark fin advocates attacking any numbers put forth but the sad truth for me is the only time we will have real accuracy is when the last shark dies in a sea world tank. Then we'll know.

Drew do you have a link to Ms Clarks paper? I can't find it now and I'm sure what I read did not include the global market in her number of 38 million, but I might have had an excerpt.

Steve

[Drew]

Steve, that's the problem. Shelley's study has been misquoted in such awful ways that it's almost hysteria. It's not an impossible goal when one can ACCURATELY quote Shelley's paper (which I believe is available on PubMed). Problem is instead of the figure she uses of 38 million, people choose to quote the high end of 73 million because of effect. Autopsea mentioned the paper in his post.
There are very real efforts right now going on working on governmental support in key countries to hit shark fin bans/restrictions, based on Shelley's research. Sounding hysterical allows naysayers to marginalize proper conservation efforts in getting measures passed in governments. It's really that simple. The 100 million number has been called to doubt since 2008/9 by many learned sources. It's not a new thing. Unfortunately, now that solid organizations like PEW etc have used the 100 million number repeatedly, they really don't want to admit inaccuracy and recant.
In any scientific source, if there's no peer reviewed published paper, then it's just people throwing a number out there. No one is faulting Eric, it's the "sources" that are the issue. Anyone who understands statistics would know this. I happen to know that many people in the conservation circles use inflated numbers for effect, and believe it's the right thing to do. I totally disagree with this form of "logic."

[Drew]

I finally got the ok to post this possible explanation of events from certain principals so here it goes:

The origin of the "100 million" number comes from Dr. Ramon Bonfil, more accurately, his technical paper "Overview of World Elasmobranch Fisheries", published in 1994. In it, Ramon estimated that elasmobranch fisheries landed about 700k tons in 1991, based on FAO fisheries data. Ramon further extrapolated that:

Official fisheries statistics do not properly reflect the amounts of sharks and rays harvested every year in the world's oceans. Although official figures report about 700 000t/yr of elasmobranchs caught at the end of the 1980's, the actual level is at least of 1 000 000t/yr and possibly 1 350 000t.

The extrapolated data of 100 million came from the estimated 1000k tons landings, which was roughly equated to 100 million animals by others. Unfortunately, this was an estimate and this figure included rays,skates etc as they are part of the Elasmobranch fisheries. Even Ameer Abdulla's IUCN report states this. Furthermore, Ramon concluded:

The by catches of sharks in large-scale high seas fisheries around the world are large, amounting possibly to almost 50% of the reported catches from commercial fisheries. The number of sharks caught annually in these fisheries during 1989–1991 is estimated at 11.6–12.7 million. The longline fisheries for tunas of Japan, Korea and Taiwan (Prov. of China) account for most of these bycatches. More detailed information is needed to address the magnitude of this problem and its effects upon shark populations. Observer programmes must be implemented for these fisheries to obtain reliable information about yields, discards, and the extent of finning practices. There are serious deficiencies in both the reporting and handling of the catch statistics. Of particular concern is the poor species discrimination which complicates appraisals.

So 100 million sharks number appears to be a conflated figure of Elasmobranchs and further estimates number of animals based on tonnage. Worst of all, that number has been pushed on by various shark advocate organizations like PEW, which uses another conflated number from Shelley's paper (the high number of 73 million) and filled the rest with unsubstantiable by-catch estimates to make the 100 million number they'd used before.

Hope this further confuses people!

[ehanauer]

Drew, I appreciate the intelligent discussion. It's advanced considerably from the first guy who called me a liar.

However, let's not lose track of the message in the details. How many sharks killed by finning is too many? Is it 20 to 30 million, or 73 million, or 100 million?

I stand by the statement that one is too many. If this discussion keeps that message from being buried, it's worthwhile.

[Steve Williams]

Thanks you for showing me the errors in my previous comments. I have edited them based on my own reading of Ms Clark’s paper.

“It's not an impossible goal when one can ACCURATELY quote Shelley's paper.”
Ok partner let’s try this. The paper Shelley Clark authored is titled Global estimates of shark catches using trade records from commercial markets, it’s in the Wiley Online Library for $35(US)

In the paper the authors explain how they “ applied Bayesian statistical methods to trade data in combination with genetic identification to estimate by species, the annual number of globally traded shark fins, the most commercially valuable product from a group of species often unrecorded in harvest statistics. Our results provide the first fishery-independent estimate of the scale of shark catches worldwide and indicate that shark biomass in the fin trade is three to four times higher than shark catch figures reported in the only global data base”
So for those who have not read the paper let me attempt to summarize. They measured fins in the Hong Kong market and based on this and some impressive models estimated the global number of sharks taken worldwide for the soup trade. From the paper;

From the section titled Estimation of the number of sharks represented
“To relate estimates of auctioned fin weights to whole shark equivalents, a series of conversion factors was applied in an integrated Bayesian estimation framework using WinBUGS software. To produce estimates of the number of sharks present, we estimated the mean weight of a single fin in each species-fin position category (e.g. blue shark-dorsal fin) and used it as the divisor for the total weight of fins in that category. The resulting estimate of the number of fins present in each category was assumed to be equivalent to the number of sharks for either dorsal or caudal fins, or twice the number of sharks for pectoral fins”.
From the Introduction
“Building upon these previous studies, we now convert species-specific fin weights in the Hong Kong market to worldwide estimates of shark catch in numbers and biomass. Our Bayesian modelling framework accounts for joint uncertainties arising from each step and the resulting probability intervals (PIs) for estimated quantities thus summarize the total uncertainty in the estimates, providing an objective means of judging the overall reliability of the estimation. Our results represent the first fishery-independent estimate of the global shark catch for the shark fin trade”,
From the section titled Estimates of shark numbers and biomass
“Estimates of the total number of sharks traded annually worldwide, based on all fin positions combined, ranged from 26 to 73 million year⁻¹ (95% PI), with an overall median of 38 million year⁻¹. Pectoral- and dorsal-based estimates were relatively similar with median values of 29–38 million year⁻¹ (95% PIs of 25–36 and 30–47 million year⁻¹, for pectoral and dorsal respectively) but caudal estimates indicated a considerably higher median of 62 million year⁻¹ (95% PI of 50–79 million year⁻¹). Application of point estimate (e.g. mean) conversion factors from the same data sets produced estimates of the numbers of sharks represented in the fin trade of 30–52 million year⁻¹ over the three fin positions for the base extrapolation scenario.”

For me personally it’s sad to think that this is the best number we have for the shark fin trade. It is somewhere between 26 and 73 million with a mean of either 38 or 62 million per year. (This was six years ago) Does anybody actually define this as an accurate number? The word “estimate” appears in the ten page paper ninety six times. I would hope that anyone who understands statistics would know the difference between data and estimates. I would also restate my earlier comment that this study does not attempt to include sharks taken for food or killed as by catch.
I understand that our opponents are going to take issue with “hysterical” numbers (I’ll bet that’s their word) but I fear any number used against the commercial interests would get the same treatment. Here is a truly hysterical number for you; when I came into this life there were about 2.5 Billion people on the planet. Now we’ve just crossed over the 7 Billion mark.

So one more time all, what number can I use when I’m standing up in front of a classroom of 6^th graders to explain that my generation is systematically wiping out one of the most beautifully designed and biologically successful creatures in the last 400 million year history of this planet so we can have a tasteless bowl of soup? I’m serious; I need to know what to say. I’m not trying to use inflated numbers for effect. What number would you use if you were making Eric’s video?
Steve

[Nick Hope]

"Tens of millions".

[Drew]

Steve
These sort of studies will always be estimated and extrapolated by their very nature reliance of reported numbers. Shelley admits herself that more data is needed for a more accurate assessment on the shark fisheries. Is using the hard to get fin trade figures a more accurate assessment versus FAO fishery data with its notorious under/non reporting from various countries?

I question the need for a "sound bite" number in the first place. There are more dire numbers to represent the consequences of over harvesting sharks like the loss of apex predators whose populations have been decimated in areas etc:

Myers, R.A., Baum, J.K., Shepherd, T., Powers, S.P. & Peterson, C.H. (2007). Cascading effects of the loss of apex predatory sharks from a coastal ocean. Science, 315, 1846–1850.

While sound bites may have an effect in garnering public awareness, all that traction is lost when it comes as proof in legislation. The conflation and obfuscation of figures by certain people (whether intentional or by mistake) may well have delayed important legislation in quite a few key markets where there is resistance to legislation.

To directly answer your question, I'd avoid using an exact number in my script. I think Nick's "tens of millions" works, as does "over 90% of apex predators lost". It's a different way of presentation, but one that can withstand criticisms of hyperbole and inaccuracy, something that some very big organizations who have much resources in this fight to save sharks now cannot do because of the sound bite numbers used.

[Autopsea]

Drew, I appreciate the intelligent discussion. It's advanced considerably from the first guy who called me a liar.

Eric, maybe it is because my english is not so good, or because I have no time right now to do such a good post as Drew did, but I never meant to offend you.
I did like the video and your work, and my remark was just a little "pointing it out". Let me explain:

As Drew explained, this number is (for all these reason) very questonable.
I would add on that, that I'm a scientist working on shark's populations, so I am very aware of all this discussion. In my work, I sometimes have to interact, and it's a very nice part of it, with fishermen, especially on markets from poor countries, which is where most of the sharks are killed.
On some market, shark finning is a real industry. I've seen a lot of sharks killed, and spoke to the fisheremen that did / sell them (i.e. https://fbcdn-sphoto...254528840_n.jpg )

And what is always, always, always coming back ?

"Yeah, we now have around 200-500 sharks a days landing in here, but we are very worried because 10 years ago is was 2000-5000. and my income is getting lower, and I don't know how I'll feed my children. And there is no more fish around to be fished, they all disapeard, partly because we fish them as sharks bait."

so, appart from the dramatic information of this, if we are back in the number thing, this mean the global catch of sharks is probably getting lower and lower every single year, and very fast. It is sad, I'm on of the first aware of how dramatic it is.

now, of course it is not such a big deal for an audience.

BUT, when we come to meet president and politics of some countries, and this very respectable man look at you and say "I'm not sure I want to hear what you have to say, I've seen other like you before, and they lied to me", it's not nice. And you feel your work is being wasted because some organisation thing they do good and rush into things without really being sure of what they say, and knowing the way to say it for each particular country's phylosophy (i.e. in Tuvalu, the spoken is more reliable than the written. If you arrive with papers, statistics and nice graphs, they just say "yeah yeah right" and smile to you, but then totally ignore it when you leave. You need to take that aspect into account).

So that is why we all should be a little carefull when we give numbers.
One last time, I'm no ennemy, and I really appologize if I've hurt you. It was not my goal. My goal is simply to say, over-using these numbers can make it harder for the people actually meeting the politics to try to stop all this.

However, let's not lose track of the message in the details. How many sharks killed by finning is too many? Is it 20 to 30 million, or 73 million, or 100 million?

I feel that one of the most acurate things to say it that the majority of sharks (individuals) are already gone, and a lot of populations will probably never recover. When you put it close to the sharks life traits, how old they are (hey, another number issue here : people say numbers like 400 millions years and all that. Most modern sharks appeared less than 100 millions years ago. Still a lot, but... : ) ).

I stand by the statement that one is too many. If this discussion keeps that message from being buried, it's worthwhile.

And I do agree.
How sad it is that a simple thing like this, that everyone knows for sure (let's say "overexploitation is bad for everyone including us") have to go through SO MANY years, money, scientist, paper, peet-review, organisation, association, politics, etc... to finally often very poor, or too late, results...
WHEN WE ALL JUST KNOW IT.

sad system, trying to make things too complicated when they in fact are very simple. It's a shame.
I'm jealous of the time, hundreeds years ago, where they were a few specialist, and kings would listen to them, and act. It did have some good sides : )

Edited by Autopsea, 15 October 2012 - 01:30 AM.

[ehanauer]

Thanks, Autopsea, Steve, and Drew.

We are all on the same side of this issue, and if my video triggers thought and discussion, it has served it's purpose.

[Autopsea]

Steve, to go further into your last question, who can actually imagine the difference between 10 millions and 100 millions ?
These number are so high that they don't really speak to most of us.
I think finding good metaphor sometimes helps. how many people live in the city where you talk ? how many days before all of them gone if there were killed at the shark's rate ?

and about numbers, just give the truth : we don't know, but it's huge, estimates speaks about tens of millions every years. It is very hard to know how many because of illegal / mafia / bycatch / local eating (I've seen a few places where people would eat the whole shark they would fish).
But I think what is important to understand is WHY, as Eric said, "one is too much".
And this goes back to the biology and ecology of sharks. How fragile they are because of all we know (time before sexual maturity, number of newbors / years with low survival rates in the wild, not all adults can reproduce once a years, very long gestation perdiod, etc..).
This mean, killing ONE sharks is a very big deal compared to killing the same weight in parrotfish for exemple. You can make, for child, paralels with sport. In your team of 11, if I take 3 aways, will they do good next season?
and then how important they are: more sharks => more fish, how fragile are relation in a ecosystem, how dynamic it is and change all the time, with or without us.

Well you know all that, but I'll be interested to know what works the best for you in passing the message. I found that using pictures with funny comments usually helps !
I'll try more ways, have a talk in a month ! : )