As N. Sea Rapidly Warms, Invasive Farmed Pacific Oysters Experiencing Explosive Growth - Independent

[hatrack]

EDIT

The Pacific oyster was introduced to European coasts in the 1970s from Japan and British Columbia following the virtual collapse of the Continent's native oyster industry. The Pacific oyster was not introduced to Sylt, which boasted a formidable pre-war oyster industry, until 1986, and then only as a product that would be carefully farmed in an environment controlled partly by man. "The Sylt oyster producers were granted a licence to fish farm, but back then all of the experts were convinced that the waters around the island were far too cold in winter to enable the oysters to survive without human intervention," Dr Reise said. But in the meantime, the experts have been proved hugely, even alarmingly, wrong.

The scale of Sylt's oyster invasion is massive. The Alfred Wegener Institute first noticed that something unusual was happening on the island's protected tidal sand flats back in 1995 –nine years after the Pacific oyster was introduced at a lone oyster farm on Sylt's northernmost tip. Handfuls of wild Pacific oysters were found that autumn nestling on an indigenous blue mussel bed that was exposed at low tide. At that stage, the island's marine biologists were not unduly surprised. A few wild, or feral, oysters were expected as a natural byproduct of the local oyster farm. In 1995 the feral Pacific oyster population was about one oyster per square metre of tidal sand flat on Sylt. By 2004 the figure had leapt to nearly 500 per square metre. By 2007 the island's feral Pacific oyster count jumped to a staggering 2,000 per square metre. "What we are now experiencing is exponential growth of the wild oyster population," says Dr Reise. "We don't yet know where the process will end."

At low tide out on the wind and wave-beaten expanses of sandy mud and seaweed, evidence of the island's oyster invasion is everywhere. Pairs of oystercatchers and the occasional Brent goose spring into flight from sands that are covered for almost as far as the eye can see with a carpet of feral oysters that crunch underfoot. Unlike those consumed in posh restaurants, these are stuck together in vast clumps made up of scores of small oysters, with the odd native blue mussel and winkle nestling in between. "Six or seven years ago there was nothing here but sand," Dr Reise said.

Marine biologists are unanimous in their explanation for the causes of the Pacific oyster invasion. Sylt, which is on the same latitude as Newcastle, used to experience temperatures that were low enough to freeze the shallow salt waters surrounding it during winter. But the last harsh winter on Sylt was at the beginning of 1996. Since then, the island has experienced nothing but mild winters. "Cold winters can bring the spread of wild oysters to a halt, but warm winters enable the oyster larvae to flourish," said Dr Reise. "Their increase is a direct result of global warming."

EDIT

http://www.independent.co.uk/environment/nature/invasion-of-the-giant-oysters-793155.html

[kestrel91316]

1. Gotta grow those Pacific oysters SOMEWHERE, and the Pacific

Coast is one big "dead zone", so maybe the North Sea will be a biological haven for them.......

(oy, I HATE the mess we have made of ecosystems - just trying to find some humor and irony in the whole debacle)