Croatian biologists fear largest Mediterranean clam near extinction

ZAGREB (Reuters) - Croatian marine biologists are struggling to save the largest Mediterranean clam from extinction after a precipitious fall in numbers which they say was probably caused by a deadly pathogen. The clam, known as the noble pen shell or pinna nobilis, plays an important ecological role by filtering sea water and allowing other organisms to flourish.

Reuters September 19, 2020 00:11:07 IST
Croatian biologists fear largest Mediterranean clam near extinction

Croatian biologists fear largest Mediterranean clam near extinction

ZAGREB (Reuters) - Croatian marine biologists are struggling to save the largest Mediterranean clam from extinction after a precipitious fall in numbers which they say was probably caused by a deadly pathogen.

The clam, known as the noble pen shell or pinna nobilis, plays an important ecological role by filtering sea water and allowing other organisms to flourish. Its shell can reach as much as 4 feet (120 cm).

The first signs of a pathogen targeting the clams came four years ago off the coast of Spain, the biologists say. The spread of the pathogen may have been helped by rising sea temperatures related to climate change, though they cannot be 100% certain.

"After the first evidence of the mass mortality of pen shells in their habitat (off Spain), the disease quickly spread across the Mediterranean. In Croatia, in the southern Adriatic, we first spotted what was going on in May last year," said Luka Katusic of the Croatian Institute for Environmental Protection.

By the spring of 2020 the whole Croatian coast had been affected.

"Mortality is extremely high and it has been proven that in localities where the causative agent of the disease appears, it can cause 100% death or extinction of pinna nobilis," Katusic said.

A year ago the aquarium in the northern Adriatic city of Pula collected some 300 seemingly healthy specimens and put them in pools hoping to save them, but fewer than 30 remain alive.

"We have been trying to make them spawn under controlled conditions to get new small, healthy pen shells. Unfortunately, most of them seem to have been already infected," said Zarko Jakovic, a biologist working at the aquarium.

The pathogen becomes inactive if the temperature of the sea water falls below 13.5 degrees Celsius, but the clams are also then unable to spawn.

"As things appear now, it will be very difficult to save the pen shells. It is already difficult to find living specimens in the sea... Sadly, all this may mean the disappearance of a species," Jakovic said, adding this would have wider consequences.

"One adult pen shell filters dozens of litres of sea water daily, which contributes to its clearness and transparency, making it easier for sunbeams to reach the seagrass meadows at the bottom.

"They are also home for many small organisms that find shelter on them," he added.

(Reporting by Antonio Bronic, writing by Igor Ilic, editing by Gareth Jones)

This story has not been edited by Firstpost staff and is generated by auto-feed.

Updated Date:

TAGS:

also read

France, Germany to agree to NATO role against Islamic State - sources
| Reuters
World

France, Germany to agree to NATO role against Islamic State - sources | Reuters

By Robin Emmott and John Irish | BRUSSELS/PARIS BRUSSELS/PARIS France and Germany will agree to a U.S. plan for NATO to take a bigger role in the fight against Islamic militants at a meeting with President Donald Trump on Thursday, but insist the move is purely symbolic, four senior European diplomats said.The decision to allow the North Atlantic Treaty Organization to join the coalition against Islamic State in Syria and Iraq follows weeks of pressure on the two allies, who are wary of NATO confronting Russia in Syria and of alienating Arab countries who see NATO as pushing a pro-Western agenda."NATO as an institution will join the coalition," said one senior diplomat involved in the discussions. "The question is whether this just a symbolic gesture to the United States

China's Xi says navy should become world class
| Reuters
World

China's Xi says navy should become world class | Reuters

BEIJING Chinese President Xi Jinping on Wednesday called for greater efforts to make the country's navy a world class one, strong in operations on, below and above the surface, as it steps up its ability to project power far from its shores.China's navy has taken an increasingly prominent role in recent months, with a rising star admiral taking command, its first aircraft carrier sailing around self-ruled Taiwan and a new aircraft carrier launched last month.With President Donald Trump promising a US shipbuilding spree and unnerving Beijing with his unpredictable approach on hot button issues including Taiwan and the South and East China Seas, China is pushing to narrow the gap with the U.S. Navy.Inspecting navy headquarters, Xi said the navy should "aim for the top ranks in the world", the Defence Ministry said in a statement about his visit."Building a strong and modern navy is an important mark of a top ranking global military," the ministry paraphrased Xi as saying.