Climate change is threatening the entire marine food chain

f13-iconPeter Brannen writes: At the Woods Hole Oceanographic Institution on Cape Cod, Massachusetts, snowdrifts piled up outside shuttered T-shirt shops, and wind and whitecaps lashed vessels tethered to empty piers in the harbour. The flood of sun-tanned tourists and research students that descends on this place in summer was still months away. The only visitor was a winter storm that hung over the coast, making travel in and out of the cedar-shingled town impossible. In a research building downtown, at the end of a dimly lit hallway, Peter Wiebe sat with a stack of yellowed composition notebooks, reliving a lifetime spent on the ocean. Wiebe, a grizzled scientist emeritus, is transcribing his research cruise logs, which go back to 1962. His handwritten notes archive a half-century of twilit cruises in the Antarctic and languorous equatorial days surrounded by marine life.

‘It’s quite clear to me things are changing,’ he told me, after I asked him to think back on his decades on the ocean. ‘As a graduate student on one cruise, my logs talk about a hammerhead and two whitetips following the ship the whole time. On other cruises, we would fish for mahimahi and tuna, and occasionally catch a shark. Now we hardly ever see any big fish or sharks at all.’

Indeed, in oceanography, the big story over the past half century – the span of Wiebe’s career – has been the wholesale removal of the seas’ top predators through overfishing. But the story of the oceans for the coming century may be a revolution that starts from the bottom of the food chain, not the top.

‘I won’t be around to see it,’ Wiebe told me. ‘I wish I were.’

Plankton (taken from the Greek word for wanderer) are the plants, animals and microbes that are unable to overcome the influence of ocean currents, either because they’re too small, like bacteria, or because, as in the case of the indifferent jellyfish, they can’t be bothered. Wiebe’s speciality is zooplankton, the kaleidoscopic, translucent animal world in miniature, much of which feeds on even smaller photosynthetic life called phytoplankton. To make the jump from photosynthesis to fish, birds and whales, you have to go through zooplankton first.

Wiebe is part of a body of researchers worldwide working feverishly to find out how these grazers will be affected by an increasingly unfamiliar ocean, an ocean that absorbs 300,000 Hiroshimas of excess heat every day, and whose surface waters have already become 30 per cent more acidic since the dawn of the Industrial Revolution.

‘When I first started, the idea that you could actually change the pH of the ocean just wasn’t there – no one expected us to be able to do it,’ Wiebe told me. ‘Certainly, no one expected us to be able to do it at the pace we’re doing it, at a pace that far surpasses anything natural that has ever happened.’ [Continue reading…]

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