Grim tale of global shark declines

25 06 2015
Please don't eat me

Please don’t eat me

How do you prevent declines of species you cannot even see? This is (and has always been) the dilemma for fisheries because, well, humans don’t live underwater. Even when we strap on a metal tank full of air and a pair of fins, we’re still more or less like wounded astronauts peering through a narrow window of glass at the huge, largely empty, ocean space. It’s little wonder then that we have a fairly crap system of estimating fish abundance, and an even worse track record of managing them sustainably.

But humans love to eat fish – the total world estimate of legal fisheries landings is something in the vicinity of 190 million tonnes in 2013, up from 18 million tonnes in 1950 (according to FAO). We’re probably familiar with some of the losers of that massive harvest, with species like tunas, bill fishes and orange roughy making the news for catastrophic declines in abundance over the last 30-40 years. And we’re not even talking about the estimated tragedy that is illegal, unreported and unregulated (IUU) fishing.

Back in 1999, the FAO started to report that sharks – the new-ish target of many world fisheries resulting from the commercial extinction of many other fin fish fisheries – we’re starting to take the hit. Once generally ignored by fishing industries, sharks soon became popular target species. Then in 2003, Julia Baum and colleagues famously (and somewhat controversially) sounded the alarm for sharks in the Gulf of Mexico by some claims of major and catastrophic declines of large, predatory sharks. While some of the subsequent to-ing and fro-ing in the literature challenged these claims, Baum’s excellent work was ultimately vindicated.

Since then, more and more evidence that sharks are in trouble has surfaced, including the assessment of the reported (again, only legal) catch indicated heavy depletion of coastal sharks even by 1975, and the estimate that 25% of all shark and ray species have an elevated extinction risk, mainly resulting from overfishing. Now even the direct fisheries landings statistics are confirming this grim tale. Read the rest of this entry »

Influential conservation papers of 2014

22 12 2014

splash2Another year, another arbitrary retrospective list – but I’m still going to do it. Based on the popularity of last year’s retrospective list of influential conservation papers as assessed through F1000 Prime, here are 20 conservation papers published in 2014 that impressed the Faculty members.

Once again for copyright reasons, I can’t give the whole text but I’ve given the links to the F1000 assessments (if you’re a subscriber) and of course, to the papers themselves. I did not order these based on any particular criterion.

Read the rest of this entry »

Evidence-based conservation advocacy can work

15 09 2014
Colin 'Captain Hook' Barnett

Colin ‘Captain Hook’ Barnett

Just before knock-off time last Friday, I received some inspiring news. It’s not often in conservation science that the news is good, so even small wins are deliciously welcome.

Unless you’ve been out bush for the last few days or completely ignored the news services, you would have heard that Western Australia has decided not to go ahead with its moronic shark-culling programme. It all came down to the Western Australia Environmental Protection Authority‘s recommendation to the state government that it should not proceed with the cull because of ‘uncertainties’ in its effectiveness and impacts. While the government could conceivably ignore this recommendation and go ahead with the cull anyway, the right-wing Premier of Western Australia, Colin ‘Captain Hook’ Barnett, stated that while he was “disappointed”, the government was unlikely to appeal the decision, at least this year.

Putting the obvious commentary on his response aside for the moment, this is a rare example where overwhelming evidence actually persuaded a semi-autonomous government agency from going ahead with clearly stupid environmental policies. I can claim a small part in this endeavour, having co-written the synopsis of the scientific consensus statement and co-signed the submission to the Environmental Protection Authority. However, it was mainly down to the hard work and dedication of Professor Jessica Meeuwig of the University of Western Australia that the Western Australia government had little choice to but to heed our condemnation. Without her, I can pretty much guarantee that the shark slaughter would be continuing this year.

As they say in France, “chapeau” to Jessica. Read the rest of this entry »

Colour-blind sharks

3 02 2011

A few weeks ago I was interviewed on Channel 10 (Adelaide) about some new research coming out of the University of Western Australia regarding shark colour vision.

I’ve received permission from Channel 1o to reproduce the news snippet here. The first bloke interviewed is Associate Professor Nathan Hart, the study‘s lead author. I’m the bald one appearing in the middle at at the end.

It certainly was an interesting story, although two claims were made that probably needed better contextualisation.

First, the authors claim that because of this taxon’s colour blindness, they probably notice pigment transitions more when using visual cues to identify potential prey. What this means is that bright colours set against duller backgrounds might provide that contrast enough to attract sharks. The upshot from the interview is that brightly coloured and patterned togs (bathers) might make sharks think you are potentially a tasty treat. Read the rest of this entry »


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