ISTANBUL: A thick, brown, bubbly foam dubbed “sea snot” has covered the shores of the Sea of Marmara, alarming Istanbul residents and raising environmental concerns.

The naturally-occurring mucilage was first documented in Turkey in 2007, when it was also seen in parts of the Aegean Sea near Greece.

But this outbreak is the largest on record, blamed by experts on a combination of pollution and global warming, which speeds up the growth of algae responsible for the slimy sludge.

Muharrem Balci, a professor at Istanbul University, said when the algae grow out of control during spring, as they have done this year, they block out the sun and cause oxygen depletion for the fish in the sea.

The viscous substance lapping the shores of Istanbul comes from a sort of nutrient overload for the algae, which feast on warm weather and water pollution that has grown progressively worse in the past 40 years, Balci said.

“This mucilage is now covering the sea surface like a tent canvas,” Balci added.

“After a while, this cover collapses to the bottom and covers the (sea floor’s) ecosystem.”

This could poison the sea’s mussels and creatures such as crabs.

“It will smell like a rotten egg unless this process is halted,” he said.

Action plan

Cevahir Efe Akcelik, an environment engineer, said this foam could cover the sea all summer unless urgent measures were taken.

“Studies show the mucilage is not only on the surface now, but also goes 25 to 30 metres deep,” he said.

The Sea of Marmara, which stretches along Istanbul’s southern coast from the Bosphorus to the Aegean Sea, is densely populated and home to numerous industrial sites.

Professor Balci said it also absorbs some of the waste that flows into the neighbouring Black Sea from the polluted Danube River, which cuts across eastern Europe.

“This is an extra burden for the Sea of Marmara,” said Balci, calling for a collective action plan for all of the sea’s coastal cities.

Workers are trying to remove the sludge with nets, but their efforts have so far proven largely ineffective.

Balci said a lasting solution required proper marine supervision as well as biological and chemical disposal systems for the sea’s cities and industrial zones.

Ali Oztunc, a lawmaker for the main opposition CHP party, urged the government to impose tough penalties on waste disposal facilities that fail to follow the rules.

“The Sea of Marmara is an inland sea but, unfortunately, it is becoming an inland desert because of the wrong environmental policies,” he observed.

On Tuesday, President Recept Tayyip Erdogan’s ruling coalition shot down a CHP proposal to set up a parliamentary committee to investigate the “sea snot”.

Oztunc also called on the Turkish government to approve the 2015 Paris agreement, which aims to limit temperature rises by cutting emissions.

“The government should approve the Paris agreement without delay,” Oztunc said.

Published in Dawn, June 5th, 2021