Urban Development Helped Fuel Turkey's'Sea Snot' Invasion

 

Urban Development Helped Fuel Turkey’s ‘Sea Snot’ Invasion

Industrialization and population growth in the Istanbul region is being blamed for a slimy outbreak of marine mucilage, threatening sea life in the Marmara Sea.

By Jennifer Hattam

June 22, 2021, 7:00 AM GMT+3

Just an hour by ferry from the crowded center of Istanbul, the Princes’ Islands are typically thronged with visitors in the warmer months of the year. But this spring, the beaches and harbors of this island chain in the Marmara Sea received a particularly unwelcome guest: a thick layer of marine mucilage, a gelatinous organic substance vividly known as “sea snot.”

The gluey microorganism blanket has spread across much of the Marmara, an inland sea connecting the Black Sea to the Aegean; underwater, the mucilage is clogging fishing nets, smothering corals and other marine life, and posing a serious threat to the marine ecosystem as well as Turkey’s fishing and tourism industries. One major culprit, experts say, is something that’s also visible from the Princes’ Islands: a line of dense urban development, stretching along the horizon as far as the eye can see.

“The biggest cause of the mucilage outbreak is untreated wastewater from all around the Sea of Marmara,” says marine biologist Bayram Öztürk, founder and director of the Turkish Marine Research Foundation.

The same rapid and unplanned growth that turned Istanbul into a sprawling megalopolis over the past half-century has been occurring around the entire Marmara region. Covering a land area approximately the size of the state of Maine, it is home to 24 million people — 30% of Turkey’s total population.

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“This large population puts great pressure not only on the Marmara Sea, but also on other water resources, including the rivers in its basin,” says Meriç Albay, a professor of limnology at Istanbul University’s Faculty of Aquatic Sciences. “Wastes have been discharged into the sea without being fully treated, coastal areas have been filled, and green spaces transformed into settlement areas.”

Since the 1960s, the Marmara region has been developed as an industrial extension of Istanbul, Turkey’s largest and wealthiest city, with the majority of both its population and commercial activity concentrated near the shoreline. Studded with shipping ports, chemical and fertilizer plants, automobile and machinery manufacturers, and other factories, the region today accounts for nearly half of the country’s industrial production and overall GDP.

That development is having significant consequences for the surrounding environment.

“When I started my career more than 35 years ago, the islands around the Marmara Sea were wild, green and quiet,” says Öztürk. “There were bluefin tuna, turbot, swordfish everywhere — you can’t believe how many.”

Before the mucilage outbreak, Öztürk says he’s noticed how diving visibility in the waters of the Marmara Sea have been declining over the years, as has many fish populations. Other researchers have calculated that at least 41 fish species have either disappeared or become commercially extinct in the Marmara since the late 1960s due to overfishing and pollution.

A semi-enclosed basin surrounded by mountains, the Marmara Sea receives the bulk of drainage from the Marmara region’s rivers, as well as some of the water carried along the Danube and Volga into the Black Sea, which has been called the most polluted in Europe.

“Geographically speaking, the Marmara Sea is in a very precarious position in terms of pollution, but these vulnerabilities do not explain why the Marmara is in the state she is in,” says Murat Güvenç, director of Kadir Has University’s Istanbul Studies Center. “It is because of the formidable mismanagement that authorities in Turkey have carried out over the last 30, 40, 50 years that we have arrived at the situation we see today.”

No single planning authority in Turkey oversees the entire Marmara region, hampering decision-making to address urbanization, environmental degradation and sustainability, according to Özlem Altınkaya Genel, a postdoctoral researcher in TU Delft’s Faculty of Architecture and the Built Environment. “This is an incredibly dynamic region, yet we know very little about it; we are not monitoring what is going on, and it is going in a very unsustainable direction,” says Genel, who recently co-authored a study analyzing land cover change in the Marmara region.

During her field research around the Marmara coast in 2015, many parts of the sea “looked like a noodle soup, full of jellyfish and plastic,” Genel says.  “I knew then that something would happen, although I did not expect this.

For years, scientists warned about the risk of a severe mucilage outbreak in the Marmara Sea. Dense sea snot also observed in the late 2000s. It is not completely certain what triggered the current flare-up, though scientists like Öztürk say that warmer sea temperatures attributed to climate change likely are also playing a role. But the underlying stressors on the sea have been numerous, and mounting.

“The sharp growth in both population and water use per capita in the cities around the Sea of Marmara in the last couple of decades has resulted in a drastic increase of overall urban wastewater discharge into the sea, more than half of which is not treated properly,” says Akgün İlhan, a water management expert at the Istanbul Policy Center.

Wastewater from the cities around the Marmara is often pumped half-treated deep into the sea, a mechanism originally devised in the wake of a cholera epidemic that killed about 50 people in Istanbul in 1970, Güvenç says. Though the method was supported by experts at the time, he says, it is no longer viable given the regional growth. Insufficient fines and enforcement also mean many industrial facilities discharge completely untreated wastewater directly into the sea, he adds.

“The Marmara Sea has been used for decades as a huge cesspool for the region’s urban development.”

Istanbul’s rapid growth also means it is tapping ever-more remote water systems such as the Melen River Basin, almost 200 kilometers away. “These interbasin water transfers exacerbate the problems by enabling cities to create much larger water footprints than their ecological borders would naturally allow,” İlhan says.

But these problems were little discussed at a policy level until the sea snot problem erupted into the public eye, Genel says. “It reminds me of the film Solaris by [Russian director Andrei] Tarkovsky, where the sea reads people’s minds and reflects everything they have been ignoring.”

The stark visibility of the problem has sparked a massive cleanup effort. More than 3,200 cubic meters of mucilage have been removed from the sea surface this month, according to figures from the Turkish Ministry of Environment and Urbanization. The government says it has also stepped up enforcement efforts against polluters and established a regional coordination committee to enact its 22-point action plan to fight the outbreak.

“Right now the government seems to be very determined, but they have to follow through; they can’t just say the problem is solved when this outbreak is cleaned up,” says Öztürk.

Albay says that coastal development and infrastructure projects have “greatly damaged the ecology of the Marmara Sea.” He is calling for more protection of these biologically sensitive zones. But further disruption is on the horizon in the form of the Kanal Istanbul project, a $15 billion artificial waterway between the Black Sea and the Marmara that has long been a priority of Turkish President Recep Tayyip Erdogan. Critics of the megaproject have warned that the canal threatens to further harm the marine ecosystem if it goes ahead.

“The Marmara Sea has been used for decades as a huge cesspool for the region’s urban development,” Güvenç says. “Its carrying capacity has been way exceeded. The sea is now revolting against that.”

By Jennifer Hattam

June 22, 2021

Bloomber