Thursday, March 5, 2015

05/03/2015: Delivering unwelcome species to the Mediterranean

The Mediterranean Sea is among the world’s great environmental jewels, says The New York Times.

The sea is highly saline, almost entirely enclosed by land and contains immense biodiversity. Scientists have long worried that its health is imperiled. Swelling coastal populations and ship traffic have brought overfishing and pollution. Climate change threatens to roil the waters still further.

One threat that is now gaining particular attention: the arrival of invasive species. One of the Mediterranean’s few outlets is the 146-year-old Suez Canal, which links it to the Red Sea and the ocean beyond. This creates a vital shipping route between Europe and Asia. But scientists fear that an expansion of the canal could bring more invasive species to the Mediterranean’s fragile waters.

Last year, Egypt announced plans to quickly build 45 more miles of waterway — a parallel canal, in part — so that ships can pass through more quickly than they do now. With the existing canal, they often must wait because the channel is narrow — about 1,000 feet wide at its slimmest point.

Because of the Suez and its expansion, the Mediterranean Sea’s problem with invasive species is becoming “worse than anywhere else on earth,” said Bella Galil, a senior scientist with Israel’s National Institute of Oceanography.

Among the unpopular arrivals are venomous jellyfish, which have unnerved tourists and sometimes obstructed water intakes belonging to electric-power or desalination plants, in addition to harming the natural ecology. Another worrisome invader is the puffer fish, sometimes known as the silver-cheeked toadfish, which releases a neurotoxin that can harm other fish and humans who consume it.

The existing Suez Canal has already served as a conduit. Invasive species are particularly concentrated in the eastern part of the Mediterranean, in the vicinity of the Suez Canal. The canal is already seen as “as one of the most significant pathways of marine invasions globally,” and it has ushered more than 350 nonnative species — including the puffer fish — into the Mediterranean, according to a letter sent in December from Julia Marton-Lefèvre, then director general of the International Union for Conservation of Nature, to Karmenu Vella, the European commissioner in charge of the environment, maritime affairs and fisheries.

Dr Galil said, “Marine invasions are forever,” because it is impossible to remove an invasive species from the sea after it has arrived. The sea and its complex food web, she added, are “teetering.”

Some invasive species hitch rides in the ballast water of ships, an issue that the International Maritime Organization is trying to address through new rules regarding the treatment of ballast water to remove stowaways. Others cling to ship hulls, but many creatures simply swim through the Suez Canal itself.

Read more HERE.

The Aquaculturists
This blog is maintained by The Aquaculturists staff and is supported by the
magazine International Aquafeed which is published by
Perendale Publishers Ltd

For additional daily news from aquaculture around the world: aquaculture-news

No comments:

Post a Comment