01.05.2013 Environment

Oceans on the Edge

Could the ocean be the site of the next significant extinction event? asks Adrian Glamorgan

The oceanic expanse can deceive us. So limitless. The Water Planet from space, a blue marble, our shared marine sanctuary, the source of life on Earth. But the ocean is not inexhaustible. Even before Columbus, sailors from Portugal, the Basque Country, Brittany and Normandy sailed across the Atlantic to the "land of the cod", to the "sea covered with fishes". Their nets were perennially heavy with sea life. Grand Banks, just off Newfoundland, proved one of the richest fishing grounds on the planet. In the last few decades, new technologies on bigger ships have changed things. Wider areas could be trawled, the nets went many fathoms deeper, and the boats stayed out for longer. On the bridge, radar and sonar found greater opportunities. The ships' bigger decks were covered by larger tonnages of cod mixed in with other species, the ones that the cod fed on. Other trawler nets scraped the seafloor. In a single hour, a factory ship could haul in as much cod as an entire 16th century season of Grand Banks' fishing.

Bigger yields seemed to vindicate the canny commercial sense of this industrial- scale fishing. Yes, there were a few words of alarm from some environmentalists, but each year the electronic gear always eventually found large schools of fish. So what was the problem? Mindful of assurances from industry, the Canadian Minister of Fisheries and Oceans rejected his stock assessor's urgent recommendation in 1989 to cut the quota by 50%, and settled instead for a 10% quota cut.

Then, in an astonishing year or two, the cod disappeared. In 1992, cod were suddenly down to one per cent of former levels. The Canadian government had waited until things were indisputably bad, and now that they were, they slapped on a complete moratorium. Signs of cod recovery were expected in a couple of years. That was 21 years ago. There is still no cod harvest. In a season or two, Newfoundland lost tens of thousands of jobs, factories, and people migrated to jobs elsewhere, leaving shattered communities. The Grand Banks collapse was a global cautionary tale.

Collapse can be found elsewhere. In the 1970s, anchovies disappeared off the coast of Peru. Overfishing and El Nino ended Peru's headline role as world supplier of fish stock. Sole has gone from the Irish Sea, the west English Channel and beyond into the Mediterranean, where all hake, red mullet and most sea bream are overexploited. And so on.

According to the 2012 "State of World Fisheries and Aquaculture", produced by the UN Food and Agriculture Organisation (FAO), overexploitation - going beyond ecological limits - has steadily grown from 10% in 1974 to 30% of all fish stocks in 2009. Hairtail fish and Japanese anchovy in the Northwest Pacific, Chilean jack mackerel and a third of the seven principal tuna species around the world, may not recover from such overexploitation. By contrast, fishing at the very ecological limits of sustainability is called "full exploitation". It's rising, from 50% of all fish netted to 57% in 2009. And on the face of it, full exploitation seems sustainable enough. Aggressive fishing has lifted overall fish stock yields globally from 16.8 million tonnes in 1950 to a recent peak of 86.4 million tonnes. But are we teetering at the edge of global collapse?

Governments are encouraged to think arithmetically, but the environment is exponential. If you try and squeeze productivity out of a system, in steps, you will get great yields, but then you risk sudden disaster. Systems - ecosystems - crash. So knowing what actually constitutes full exploitation - living within ocean means - requires accurate scientific data. But there is much uncharted, and frequent surprises. In Australia, a Ningaloo World Heritage deep water project in 2009 revealed 600 marine species, including many new to science, such as 18 new sea stars and sea urchins, three mollusc species, and more than 50 new sponge species. Much of that research was carried out only in depths of less than 20 metres. There is much for us to learn about our coastline, let alone beyond the horizon.

With the factory ships and supertrawlers hungry for protein, the ocean floor is being scraped. At these depths, slow-growing fish are being piled into nets to make up for the losses closer to the sea surface. But it's like chopping down slow-growing trees. At such depths, ecosystems take longer to recover. Not decades, but centuries. The more overfishing there is, the smaller the catch, and the less need for the supertrawlers. Instead, these supertrawlers look to cull the very last fish from the oceans. As ecologist Dr Vandana Shiva reminds us, "It is not an investment if it is destroying the planet."

There is hope, but first we must face realities, even more harsh. Our oceans are in peril from rising water temperatures. Professor Lyn Beazley, Western Australia's chief scientist, recently warned that a marine heatwave in the summer of 2010-11 heralded "very significant changes", including the bleaching of Ningaloo Reef. A five degree increase in sea surface temperature off the Gascoyne and Mid West coastlines brought the collapse of crabs, abalone and scallops, along with seaweed habitats. Tropical fish moved further southward. Marine conservationist Professor Callum Roberts and colleagues have mapped global biodiversity distribution of reef fishes, indicating the unsettling news that marine species are at risk of extinction across the planet.

There is hope. In November 2012, the Australian Government announced the creation of the largest network of marine reserves in the world. A very good start, and a beacon to other countries. It's been estimated to impact only on one per cent of the commercial fishing industry nationally, and a Fisheries Adjustment Assistance Package provides $100m. Given Australia has the third largest marine estate of any nation in the world, we have a lot to protect, from tropical seas of the north to the sub Antarctic. The 40 new marine reserves will be added to existing reserves, for biodiversity conservation. This is necessary infrastructure, but it will not be sufficient to stem even bigger challenges.

In April 2011, the ocean experts of the world gathered at the Margaret Thatcher Conference Centre at Oxford University to consider our future, from today through 2020-2050. It seems "negative changes to the ocean are near to or are tracking the worst case scenarios" from IPCC (the UN Intergovernmental Panel on Climate Change made up of 2000 scientists from around the world) and others. Some changes "are predicted, but many are faster than anticipated, and many are still accelerating". You may not know what hypoxia, acidification, toxicity, dead zones, overextraction, and nitrogen loading decline might mean in great detail - but you can guess none of this is recommended! The scientists concluded, "not only are we already experiencing severe declines in many species to the point of commercial extinction", but that we risk "the next significant extinction event in the ocean." That would be on top of the five global extinction events of the past 600 million years.

There are things you and I can do, such as supporting the Australian Marine Conservation Society, Australian Conservation Foundation, PEW Environment Group's Global Ocean Legacy project or Greenpeace: important contributors to raising community awareness.

But it's time to make the leap. Email your local MP and provide them with the facts of ocean depletion and fish stock collapse. Quote former Costa Rican President, José María Figueres, that, "The world urgently needs to find better ways of managing the oceans, to stop abuse of its precious resources and ensure its protection for present and future generations."

Figueres chairs the new independent Global Ocean Commission, based at Oxford University, which aims to end the degradation of the ocean. Figueres is joined by South African cabinet minister Trevor Manuel and former British Foreign Secretary David Miliband MP, who says, "The UN Law of the Sea was a great achievement, but we urgently need a governance framework that delivers its aims and objectives for today's global ocean." On that basis alone, ask your MP how committed she or he is to urgently improving global governance of the oceans. Keep things courteous, of course. This is going to need persistence, on a timeline only cut short by nature itself.

Adrian Glamorgan

Adrian Glamorgan is a passionate advocate of social change and environmentalism