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International Conspiracy to Catch All Tunas

2 11 2008

Otherwise known as the International Commission for the Conservation of Atlantic Tunas (ICCAT) based in Madrid, ICCAT is charged with “the conservation of tunas and tuna-like species in the Atlantic Ocean and its adjacent seas”. However, according to a paper entitled Impending collapse of bluefin tuna in the northeast Atlantic and Mediterranean to forthcoming in Conservation Letters (read post about the journal here) by Brian MacKenzie of the Technical University of Denmark, they don’t seem to be doing their job very well.

In perhaps the best example of the plundering of the seas for overt profit instead of food provision per se, the north-east Atlantic and Mediterranean population of bluefin tuna (Thunnus thynnus) has been overfished and will continue to decline to near extinction if the harvest isn’t stopped immediately and for several years to come.

Chronically obese probability.

The demand (and money) associated with tuna harvest appears to negate all scientific evidence that the population is in serious trouble – because of us. The Economist recently featured the paper’s results and therein quoted the opinion of independent ICCAT reviewers who described the situation as “an international disgrace” (read full article here).

I want to list MacKenzie et al.’s paper forthcoming in Conservation Letters as a ‘Potential‘ here at ConservationBytes.com, but I doubt it will change the tuna’s situation that much, and it may only ruffle a few European (and Japanese) feathers (scales?). Who knows? Perhaps the paper will result in a massive down-scaling of the harvest and some serious commitment to REAL tuna conservation.

CJA Bradshaw

Comments : 6 Comments »
Tags: biodiversity, conservation, fisheries, science
Categories : conservation, decline, exploitation, extinction, fish, fisheries, population dynamics, threatened species

The yob factor in conservation

29 09 2008

I believe that I am like most people when I say that I am generally annoyed by, but can live with, the yob (a.k.a. bogan, booner, westie, bevan, chigger, chav) culture pervading our society. I can live with the hooning (Why do they believe that pressing the foot 1 cm closer to the floor increases their perceived virility? I extend my curled little finger in response), bad music, mullets (indeed, those are just plain entertainment), their appalling diet, smoking and fashion statements (even more entertaining), and I can even live with their conservative political perspectives. After all, we live in an open and democratic society where one can choose to live anywhere within the yob-wanker spectrum (apologies to T.I.S.M.).

What I find more problematic is the overt anti-environmentalism the yob culture embraces. Sure, every time the petrol price notches up, I smile inside just a little bit at every unheard curse emanating from yobs around the country as they painfully fill their petrol-sucking yob cars with the latest in potential GHG emissions (small justices are hard won). But the real problem lies in the over-exploitation of our already stressed environments from some of our less-than-conscientious fisher friends. Not all recreational fishers are the kind that sport the classic ‘I Fish and I Vote’ stickers (also very amusing¹) on the back of their utes, nor are they all convinced that fishing is an inalienable right granted by Poseidon himself. But a lot are.

Case in point, I found this little nugget in a certain state government’s ‘Recreational Fishing Guide‘ by a prominent producer of those petrol-guzzling yob cars:

Excuse me? Yes, you read correctly, the STATE GOVERNMENT’S Recreational Fishing Guide.

Is this really the kind of mentality that the state government is trying to promote amongst its recreational fishing community? Do we really believe that recreational fishing is so innocuous that plainly ridiculous acts that flout even the state’s own regulations are to be encouraged? I’d like to think otherwise, but I am clearly aware that there is high probability that I’ve hit the nail on the head.

Don’t get me wrong, I’ve fished many times myself and grew up with a father who would avoid any lake where another person was fishing just to have another lake to himself. I like fish and enjoy eating freshly caught ones when I can (which is not very often because I do not own a boat or fishing gear).

So, what’s the problem? This brings me to the core of this post and the reason I started with the uncharacteristic rant. Most fisheries around the world are already in big trouble (see previous post on this subject here), so when the number of intense-use recreational fishers is high, we have recipe for disaster.

A paper by Cooke & Cowx that appeared in 2004 entitled The role of recreational fishing in global fish crises gets my vote for the Potential list here at ConservationBytes.com. This paper identified that recreational fishing could account for as much as 12 % of the global fish harvest and lead to severe declines in fish populations, especially where participation is high and commercial fisheries operate in tandem. Again, a classic example of the tragedy of the commons. Lewin and colleagues in 2006 reiterated the point and demonstrated that recreational fishing must be tightly managed and good practices encouraged to avoid localised depletions and population declines.

So when state agencies encourage yobs to behave in ways our little advert implies (I can hear the ‘YEAHS and ‘WOOHOOS’ too clearly), we are failing to manage our tragic common goods correctly and to promote good practice. Indeed, for the very reason that good behaviour ensures a longer and more fulfilling future of angling for everyone, shouldn’t we be promoting the ‘less-is-more’ mantra more aggressively?

CJA Bradshaw

¹I’ve always wondered about how people who put ‘I XXXX and I Vote’ stickers on their cars work through the logic. I eat toast and I vote, and I like rugby and I vote, and I detest listening to country music and I vote. I just ‘vote’ for the least idiotic of the choices presented before me at each election.

Comments : 14 Comments »
Tags: biodiversity, conservation, science
Categories : animal welfare, Australia, decline, education, fish, fisheries, harvest

Classics: Fishing down the web

17 09 2008

A Classic…

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Daniel Pauly and colleagues’ classic paper in Science, Fishing down marine food webs, is one that merits citation in ConservationBytes.com Classics section. The trend identified by Pauly and colleagues is fairly simple – data from the Food and Agriculture Organisation (FAO) of the United Nations revealed that the average trophic level (i.e., the position in the food web relative to autotrophs – primary producers such as phytoplankton) has declined by an overall average of 0.2 units. In this case, a trophic unit varied from 1 (phytoplankton) to 4.6 (e.g., snappers, family Lutjanidae). The trends varied by region and whether or not one takes certain overrepresented species into account, but the average decline was more or less consistent across the dataset.

What does all this reveal? Put simply, it means that fishing on a massive and global commercial scale has essentially removed many of the larger species to the point where it has become no longer economically viable to sustain a targeted fishery. This does not necessarily mean that these species have disappeared, but it does indicate a large drop in relative abundance (and thus, ease of capture) necessary to support an industry, with the corollary that highly reduced populations are now much more extinction-prone if they fall below their minimum viable population size. The corollary is that marine species we wouldn’t consider palatable for a dog 50 years ago are now considered top-quality market delicacies.

The paper did not go without critique – Caddy and colleagues argued that Pauly and colleagues oversimplified the case for marine fishes and misinterpreted some data; however, a subsequent paper by Pauly’s team published in 2005, Fishing down marine food web: it is far more pervasive than we thought, argued that the original paper didn’t go far enough, and that fisheries over-exploitation worldwide is much worse than originally reported. Indeed, there are certainly some high-profile examples to support the case (e.g., the Atlantic cod and Peruvian anchoveta fisheries collapses, to name a few).

What did this do for biodiversity conservation? I think it can be argued that this is one of the first big papers to identify that the over-fishing problem was global in extent and massive in magnitude, and that high-seas over-exploitation was stripping our seas of its bigger (generally slower-growing and more extinction-prone) species. I believe things have changed for the better, but we’re still a long way off. Fishing in international waters still operates without an international body to enforce regulation and document catch precisely, and the classic tragedy of the commons applies so well to fisheries that it should be one of the principal examples used to illustrate the concept. People tend to jump up and down about elephants, pandas and whales, but the reduction in fish worldwide is a biodiversity crisis in progress that has not attracted nearly enough attention. We need more papers like Pauly’s on this issue, as well as demonstrations of the loss of marine ecosystem function and services with the loss of species brought about by excessive fishing harvests. Only then can we expect the careless greed driving quick-profit high-seas fisheries to ease up enough to prevent extinctions on a massive scale.

CJA Bradshaw