Tuna and mackerel populations suffer catastrophic 74% declin

[Oscar]

Tuna and mackerel populations suffer catastrophic 74% decline, research shows

[ http://www.theguardian.com/environment/ ... MP=ema_565 ]

WWF says we risk losing species critical to human food security unless action is taken to halt overfishing and other threats to marine life

Fiona Harvey Wednesday 16 September 2015 00.01 BST

WWF and the Zoological Society of London found that numbers of the scombridae family of fish, which also includes bonito, fell by 74% between 1970 and 2012, outstripping a decline of 49% for 1,234 ocean species over the same period.

The conservation charity warned that we face losing species critical to human food security, unless drastic action is taken to halt overfishing and other threats to marine life.

Louise Heaps, chief advisor on marine policy at WWF UK, said: “This is catastrophic. We are destroying vital food sources, and the ecology of our oceans.”

Attention in recent years has focused on species such as bluefin tuna, now on the verge of extinction, but other close relatives commonly found on restaurant menus or in tins, such as yellowtail tuna and albacore, are now also becoming increasingly scarce. Only skipjack, also often tinned, is showing “a surprising degree of resilience”, according to Heaps, one of the authors of the Living Blue Planet report, published on Wednesday. [ http://assets.wwf.org.uk/downloads/livi ... t_2015.pdf ]

Other species suffering major declines include sea cucumbers, a luxury food in Asia, which have fallen 98% in number in the Galapagos and 94% in in the Egyptian Red Sea. Populations of endangered leatherback turtles, which can be seen in UK waters, have plummeted.

Overfishing is not the only culprit behind a halving of marine species since 1970. Pollution, including plastic detritus which can build up in the digestive systems of fish; the loss of key habitats such as coastal mangrove swamps; and climate change are also taking a heavy toll, with the oceans becoming more acidic as a result of the carbon dioxide we are pouring into the atmosphere.

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Heaps urged people only to eat fish certified as sustainable by the Marine Stewardship Council (MSC), which examines fisheries against a range of criteria to ensure that they are being properly managed. An increasing number of fisheries have been accredited by the MSC, and at present about half of global white fish stocks are certified, including many in the North Sea.

She called for more partnerships between private sector fishing fleets and governments, in order to conserve stocks. “We need to keep [fishermen] on board, because they must see that good governance is in their interests,” she said.