Turkey: Can the Marmara sea be saved? | DW Documentary

Key Concepts

• Sea Snot (Algol Slime): A gelatinous substance formed by excessive algal growth due to nutrient pollution and rising water temperatures, depleting oxygen levels and harming marine life.
• CTD Sensor: A device used to measure key seawater properties like temperature, salinity, oxygen levels, and conductivity.
• Ghost Nets: Abandoned fishing nets that continue to trap and kill marine life.
• Eutrophication: The excessive enrichment of a body of water with nutrients, leading to algal blooms and oxygen depletion.
• Bosphorus Strait & Sea of Marmara: Crucial waterways connecting the Mediterranean and Black Seas, facing severe ecological challenges.
• Sustainable Fishing: Fishing practices that maintain healthy fish populations and ecosystems for future generations.

The Deteriorating State of the Sea of Marmara: A Fight for Survival

Introduction

The Sea of Marmara, a vital waterway connecting the Mediterranean and Black Seas, is facing a severe ecological crisis. Recurring outbreaks of algal slime, declining fish populations, and pervasive pollution threaten the livelihoods of coastal communities and the health of the entire ecosystem. This report details the current situation, the contributing factors, ongoing efforts to mitigate the damage, and the perspectives of those directly affected.

1. The Return of the Slime & Impact on Fisheries

In 2021, the Sea of Marmara experienced a massive bloom of “sea snot” – a thick, gelatinous algal slime. While temporarily receding, the slime is now reappearing, posing a renewed threat. This phenomenon, visually described as the sea “vomiting,” suffocates marine life by depleting oxygen. The impact on fisheries is devastating. Needla Kosayolu, a 63-year-old fisherwoman with 50 years of experience, exemplifies this decline. She notes a drastic reduction in her catch, from 50-60 kilos daily in the 1960s to struggling to catch 10 kilos today. Traditional fishing seasons are shrinking, forcing reliance on a short two-month period (May-June) for annual income. She laments, “We used to be excited about going out to fish… But after 1990, fish stocks declined more and more.” The economic hardship is compounded by rising fuel costs, making even minimal catches unsustainable.

2. Scientific Investigation & Underlying Causes

Researchers from the Middle East Technical University (METU) are actively monitoring the situation. Professor Hassan Eric, an oceanographer, explains that the primary drivers of the slime are rising water temperatures and excessive nutrient input from untreated wastewater. This excess leads to phytoplankton blooms, and when these organisms die and decay, they create the slime. Using a CTD sensor, the team measures seawater properties (temperature, salinity, oxygen, conductivity) and visual evidence confirms the widespread presence of slime, particularly between 15-30 meters depth. Data indicates the situation is likely to worsen, potentially mirroring the 2021 crisis. Oxygen levels at the seabed have plummeted by 80% since the 1990s, creating “dead zones” where marine life cannot survive.

3. Pollution Control & Regulatory Efforts

Authorities in Istanbul recognize the severity of the problem and have declared the Sea of Marmara a “special environmental protection area.” Aishan Adener, head of Istanbul’s Department of Environmental Protection, highlights efforts to monitor and reduce pollution. 81 cameras continuously monitor the coastline, covering approximately 400 km, to detect illegal dumping of sewage and oil. The department collected around 300,000 cubic meters of waste oil, sewage, and waste in 2024. Fines for illegal fuel dumping have been increased by 60% and then another 40%, but enforcement remains a challenge. Adener acknowledges that these efforts are “little more than a drop in the ocean” compared to the scale of domestic and industrial pollution. A single liter of discarded oil can contaminate a million cubic meters of seawater.

4. The Problem of Ghost Nets & Citizen Science

Beyond pollution, abandoned fishing nets – “ghost nets” – pose a significant threat. Satio Exan, a retired diver, has been voluntarily removing these nets from the seabed around the Adalar Islands for 20 years. These nets continue to trap and kill marine life for years. Exan and his diving partner, Erjan Akpulat (the local mayor), have become known as “ghost net hunters.” The increasing presence of slime is making their work more difficult, creating massive, heavy clumps that hinder net retrieval. Exan repurposes the recovered nets, providing them to farmers in eastern Turkey for use as protective coverings for crops. He also documents the underwater environment, sharing his footage with scientists.

5. Community Voices & The Future of Fishing

The documentary highlights the perspectives of those most affected. Needla Kosayolu’s story embodies the loss of a traditional way of life. Her family has been involved in fishing for generations, with her mother being the first female fisherwoman in Turkey. She fears that fishing will become a relic of the past, existing only in encyclopedias. Her grandson, Rizgar, expresses a desire to continue the tradition, but the future remains uncertain. Needla actively participates in workshops and conferences, representing small-scale coastal fishers and advocating for sustainable practices. She states, “Until the day I die, I’ll fight for the survival of traditional coastal fishing.”

6. Conference Outcomes & Lack of Concrete Action

Annual conferences bringing together scientists, officials, and fishers aim to address the crisis. However, the documentary portrays a sense of pessimism following these meetings, as concrete measures are lacking. Marine biologist Mustafa Sada’s presentation at a recent conference warned of a potential annual recurrence of the slime outbreaks. Needla expresses frustration with the lack of progress, fearing that both commercial and traditional fishing will ultimately disappear.

Conclusion

The Sea of Marmara is facing an escalating ecological crisis driven by pollution, rising temperatures, and unsustainable practices. While efforts are underway to monitor the situation and mitigate the damage, the scale of the problem demands more comprehensive and decisive action. The voices of those directly impacted – the fishers, divers, and scientists – underscore the urgency of the situation. Without significant investment in wastewater treatment, pollution control, and sustainable fishing practices, the Sea of Marmara risks irreversible ecological collapse, threatening not only its marine ecosystem but also the livelihoods and cultural heritage of the communities that depend on it. The future of the sea, and the traditions it supports, hangs in the balance.