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 »

Western Australia’s moronic shark cull

4 07 2014

another stupid politicianA major media release today coordinated by Jessica Meeuwig in Western Australia makes the (obvious) point that there’s no biological justification to cull sharks.

301 Australian and International Scientists experts have today provided their submission to the Western Australia Environmental Protection Authority (EPA), rejecting the scientific grounds for the proposed three-year drum-line programme.

Coordinating scientist, Professor Jessica Meeuwig from the University of Western Australia said:

“To have over 300 researchers, including some of the world’s top shark specialists and marine ecologists, all strongly agreeing that there is no scientific basis for the lethal drum-line programme, tells you how unjustified the government’s proposal is. If the EPA and the Federal Minister for the Environment are using science for decisions, the drum-line proposal should not be approved.”

The experts agree that the proposal presents no evidence that the lethal drum-line programme, as implemented, will improve ocean safety. It ignores evidence from other hook-based programs in Hawaii and Queensland that have been shown to be ineffective in reducing shark attacks on humans.

Dr. Christopher Neff from the University of Sydney stated:

“There is no evidence that drum lines reduce shark bites. The Western Australia EPA now faces a question of science versus politics with global implications because it is considering establishing a new international norm that would allow for the killing of protected white sharks.”

The drum lines are ineffective and indiscriminate, with 78% of the sharks captured not considered ‘threatening’ to humans. Yet, scientifically supported, non-lethal alternatives such as the South African ‘Shark Spotter’ and Brazil’s ‘Tag and Remove’ programmes are not adequately assessed as viable options for Western Australia. Read the rest of this entry »

Biodiversity needs more than just unwanted leftovers

28 02 2014

calm oceanThe real measure of conservation progress, on land or in the sea, is how much biodiversity we save from threatening processes.

A new paper co-authored by Memorial University’s Dr Rodolphe Devillers and an international group of researchers argues that established global marine protected areas are too often a case of all show with no substance and do not adequately protect the most vulnerable areas of the world’s oceans.

“There is a big pressure internationally to expand global MPA coverage from around 3 % of the oceans to 10 %, resulting in a race from countries to protect large and often unused portions of their territorial waters for a minimal political cost,” said Mr. Devillers. “Marine protected areas are the cornerstone of marine conservation, but we are asking whether picking low-hanging fruit really makes a difference in the long-term, or if smaller areas currently under threat should be protected before, or at the same time as, those larger areas that are relatively inaccessible and therefore less used by people.

“We need to stop measuring conservation success in terms of square kilometres,” he added. “The real measure of conservation progress, on land or in the sea, is how much biodiversity we save from threatening processes. Metrics such as square kilometres or percentages of jurisdictions are notoriously unreliable in telling us about the true purpose of protected areas.” Read the rest of this entry »

Biowealth: all creatures great and small

4 12 2013

Curious Country flyer“So consider the crocodiles, sharks and snakes, the small and the squirmy, the smelly, slimy and scaly. Consider the fanged and the hairy, the ugly and the cute alike. The more we degrade this astonishing diversity of evolved life and all its interactions on our only home, the more we expose ourselves to the ravages of a universe that is inherently hostile to life.”

excerpt from ‘Biowealth: all creatures great and small’ The Curious Country (C.J.A. Bradshaw 2013).

I’ve spent the last few days on the east coast with my science partner-in-crime, Barry Brook, and one of our newest research associates (Marta Rodrigues-Rey Gomez). We first flew into Sydney at sparrow’s on Monday, then drove a hire car down to The ‘Gong to follow up on some Australian megafauna databasing & writing with Bert Roberts & Zenobia Jacobs. On Tuesday morning we then flitted over to Canberra where we had the opportunity to attend the official launch of a new book that Barry and I had co-authored.

The book, The Curious Country, is an interesting experiment in science communication and teaching dreamed up by Australia’s Chief Scientist, Professor Ian Chubb. Realising that the average Aussie has quite a few questions about ‘how stuff works’, but has little idea how to answer those questions, Ian engaged former Quantum star and science editor, Leigh Dayton, to put together a short, punchy, topical and easily understood book about why science is good for the country.

Yes, intuitive for most of you out there reading this, but science appreciation isn’t always as high as it should be amongst the so-called ‘general public’. Ian thought this might be one way to get more people engaged.

When honoured with the request to write an interesting chapter on biodiversity for the book, I naturally accepted. It turns out Barry was asked to do one on energy provision at the same time (but we didn’t know we had both been asked at the time). Our former lab head, Professor David Bowman, was also asked to write a chapter about fire risk, so it was like a mini-reunion yesterday for the three of us.

Read the rest of this entry »

King for a day – what conservation policies would you make?

29 11 2013

CrownI have been thinking a lot lately about poor governance and bad choices when it comes to biodiversity conservation policy. Perhaps its all that latent anger arising from blinkered, backward policies recently implemented by conservative state and national governments in Australia and elsewhere that leads me to contemplate: What would I do if I had the power to change policy?

While I am certain I have neither the experience or complete knowledge to balance national budgets, ensure prosperity and maintain the health of an entire country, I do have some ideas about what we’re doing wrong conservation-wise, and how we could potentially fix things. This is not meant to be an exhaustive list – it is more a discussion point where people can suggest their own ideas.

So here are 16 things I’d change or implement (mainly in Australia) if I were king for a day:

Read the rest of this entry »

Medieval Canada threatens global biodiversity

25 11 2013

harper_scienceArtists, poets and musicians make us feel, viscerally, how people destroy what they do not understand. Logic and observation led E. O. Wilson to conclude: ‘If people don’t know, they don’t care. If they don’t care, they don’t act.’

Whether you feel it in one of Drew Dillinger’s poems1 or visualise it from the sinuous beauty of mathematical equations, the song remains the same. Scientists are critical to the present and future of the biosphere and humanity, but if — and only if — we are free to communicate our findings to the voting public.

Galileo did not have that right. Scientists in totalitarian regimes of today still lack it. And now, incredibly, some of Canada’s top scientists have lost that right2,3,4.

That is not the Canada I immigrated into. Rewind the tape to 1983. I am a young immigrant, ecstatic that my family has gained entry into the country. We all have mixed feelings; we love our home country of Mexico and are sad to leave it, yet we look forward to being part of Canada’s open-minded and science-loving spirit. The tape runs forward and not all turns out to be as advertised. Still, for the next 23 years Canada remains a damn good place, ruled by governments that, imperfect as they might have been, were not obsessed with burying science.

Fast forward the tape to 2006. Stephen Harper’s newly elected and still ruling Conservative Government hits the ground pounding punches in all directions. Almost immediately, the Conservatives begin to implement one of their many Machiavellian tactics that aim to turn Canada into a petro-state6,7: downgrade science as irrelevant to evidence-based decision making. Ever since, Canadian federal scientists have seen their programs slashed or buried. Those who manage to hang on to their jobs are strictly forbidden to speak about their findings to the media or the public8,9,10,11.

Read the rest of this entry »

Fast-lane mesopredators

29 07 2013

Another post from Alejandro Frid (a modified excerpt from a chapter of his forthcoming book).

I fall in love easy. Must be my Latino upbringing. Whatever it is, I have no choice on the matter. So for five years and counting, I have been passionate about lingcod (Ophiodon elongatus) and rockfish (Sebastes spp.), upper- and mid-level predatory fishes on rocky reefs of the Northeast Pacific.

Lingcod are beautiful and fierce. Rockfish are cosmic. Both taste mighty good and—surprise, surprise—have been overfished to smithereens throughout much of their range. Howe Sound, my field site near Vancouver, British Columbia, is no exception, although new protective legislation might be starting to give them some slack.

Our dive surveys1 and earlier studies, in combination, have pieced together a story of ecosystem change. In the Howe Sound of today, lingcod rarely exceed body lengths of 80 cm. But up to 30 years ago, when overfishing had yet to inflict the full extent of its current damage, lingcod with lengths of 90 to 100 cm had been common in the area. There is nothing unique about this; most fisheries target the biggest individuals, ultimately reducing maximum body size within each species of predatory fish.

As predators shrink, the vibrant tension of predation risk slips away. The mechanism of change has a lot to do with mouth size. Predatory fishes swallow prey whole, usually head or tail first, so it is impossible for them to eat prey bigger than the width and height of their open jaws. And bigger fishes have bigger jaws, which makes them capable not only of consuming larger prey, but also of scaring bigger prey into using antipredator behaviours, such as hiding in rocky crevices. As predators shrink, big prey enter a size refuge and only small prey remain at risk, which can alter trophic cascades and other indirect species interactions. Read the rest of this entry »


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