The Golden Horn, as it is called by Westerners because of its location and the facilities it offers, is a place that has always managed to maintain its importance. It served as a natural port during the Byzantine and Ottoman periods and is home to many historical and cultural sites.

Apart from its valuable shoreline, it has also played a significant role as an important body of water. Throughout history, water has contributed to the development of civilizations and facilitated trade and transportation. The Golden Horn is the bay of Istanbul, the only city in the world spanning two continents. It is a sheltered natural harbor. As such, it has provided numerous services to civilizations throughout history.

Bays are also important habitats for aquatic creatures, and the Golden Horn is no exception. It hosts dozens of fish, aquatic plants and many other species, and offers a suitable environment for their growth and reproduction. Thanks to its rich marine ecology, it is also popular with underwater enthusiasts.

History disappearing?

Plagued by years of war, our country exerted great efforts to heal its wounds and plan its cities again. However, admiration for the West manifested itself here as well, and we hired city planners from the West – as if we had no architects or urban planners of our own. Planning was implemented.

The Golden Horn area is one of the places that fell a victim to this situation. French architect Henri Prost recommended opening the region up to industry. The Golden Horn, surrounded by industry, has been exposed to the waste and poisonous water of these facilities for years. The pollution was so extreme that the air around its shores became unbreathable.

The first steps were taken by then-Istanbul Mayor Bedrettin Dalan to recover the Golden Horn’s essence. The industrial production was moved. The disposal of waste was partially managed. However, the pollution that had flowed into the bay for years had turned the area into something resembling a putrid sewer. Garbage floated where fish should have been swimming. The sludge accumulated on the bottom and the dirt on the surface exuded a horrible stench.

Nurettin Sözen, Dalan’s successor, left the Golden Horn to its fate, so to speak. The unpleasant smell of the Golden Horn enveloped the seven hills of the city.

At the time, the Golden Horn was not the only problem plaguing Istanbul. Air pollution, water shortages, piles of garbage in the heart of the city and an explosion caused by gases produced by the garbage that claimed 39 lives were just a few of the issues facing Istanbul. These were just the tip of the iceberg.

One proposal for the Golden Horn was to fill the area with soil, meaning the Golden Horn would be destroyed.

Long-awaited savior

Fortunately, then-Istanbul Mayor and current President Recep Tayyip Erdoğan came to rescue. On March 27, 1994, Istanbul elected its new leader, and the next day, he started the journey toward saving and transforming the Golden Horn.

Erdoğan put the gangrenous problems of Istanbul on the table, and one of the issues he prioritized was the environment. It would not be wrong to say that the ill-fortune regarding the environment in our country was changed by the 1994 local elections in Istanbul. Erdoğan gathered the leading academics in environmental management issues and started to solve environmental problems.

Returning to essence

Erdoğan’s reclamation project started on Jan. 10, 1997; however, despite the limited and sometimes inadequate technology, finances and facilities of the period, it was completed in a short period, about 1 1/2 years.

First, the area was dredged – which revealed that the depth of the Golden Horn had dropped to just 10 centimeters (4 inches) in areas where the pollution had piled up, while the depth between Sütlüce and Eyüp had been reduced to between zero and 50 centimeters.

The sludge removed was pumped to the site of the old stone quarries in Alibeyköy, 7 kilometers (4.3 miles) from the Golden Horn, via pipes using cutting-edge technology. Thus, both transportation became easier, and pollution was eliminated.

To this end, four pipelines were built, reaching a total working capacity of 4,000 square meters per hour. To put it in perspective, 1 1/2 Olympic pools were transported over 7 kilometers every hour.

The work in the Golden Horn was carried out in an area that was 4.5 meters long and 200 meters wide and had an average depth of 5 meters. A total of 5 million square meters of sludge were removed.

Had the transportation of removed material been done with land-based vehicles instead of through pipelines, the trucks would have had to come and go at least 400 times a day and at least 200,000 times in total. Can you imagine the turmoil the 400 trips would have created every day? However, the team led by Erdoğan succeeded with a scientific approach.

The excavated sludge was not simply thrown away. Two dams were built in stone quarries featuring leak-proof seals for the disposal that would not harm the environment and public health.

A total of 850,000 square meters of rock, clay and filter materials were used in the construction of the dams. Once completed, a 180,000-square meter fill area was formed.

Once the water of the Golden Horn was cleared, aquatic creatures began to flock to the area. Fish were now swimming in the area instead of garbage. In fact, a fishing competition was even held. The first competition was won by a person who caught 128 fish in 1 1/2 hours.

Cleaning is not enough

Once the pollution had been eliminated, it was time to prevent future waste from contaminating the Golden Horn. The Istanbul Water and Sewerage Administration (İSKİ) developed projects and increased the management of wastewater flowing directly into the bay.

Through the new system, wastewater was transferred to treatment units by collectors, preventing recontamination. Many wastewater collectors, tunnels and discharge lines, exceeding 120 kilometers in length, were constructed during the efforts referred to as the Northern and Southern Golden Horn projects.

The Northern Golden Horn project cost İSKİ TL 118 trillion in 2000, while the Southern Golden Horn project cost TL 92 trillion. Investment in the Golden Horn, one of the largest environmental projects in the world, amounted to $520 million at fair values at the time.

To solve these problems, infrastructure investments continued for years. Infrastructure and sewage systems were renewed, and their capacities were increased.

Not only the Golden Horn area, but the whole of Istanbul was renovated in this process. Over the last 25 years, a 17,500-kilometer wastewater collection system service was launched in Istanbul. In addition, 4,500 kilometers of rainwater collection services were commissioned. These investments reduced pressure on the creeks. But it was not enough. There are 68 streams in Istanbul. Reclamation work was carried out on these streams on an area exceeding 500 kilometers, but things were never easy. A 100-kilometer section of the streams passing through settlement areas where people were living was especially challenging.

World Urbanism Award

In 2002, a competition was organized on the basis of environmental projects of metropolitan municipalities in Japan. Our country participated with the Golden Horn Project and came in first in the competition, winning the World Urbanism Award.

Again, within the scope of the Environmental Services Awards presented by Akdeniz University on a national basis, the Golden Horn water project was given the award in 2014.

Today’s debate

Let us come to the current issue of algae blooms. Of course, this is not a first in our country or in the world. However, claiming that it is completely natural means whitewashing some problems. For instance, when there is a problem with our body, our body balance manifests itself with signs of fever or pain. This applies to the Golden Horn as well.

There must be an ecological balance between living and inanimate beings on our planet. Unless this balance is disrupted, preventing it from repairing itself in case of damage, the system has the ability to balance and renew. As a result of human activity, many pollutants released into nature can be managed in some way when they remain within the limits that allow nature to repair itself.

Just as our blood has iron and vitamin requirements and the body gets sick and requires external intervention when boundaries are crossed, the same is true for nature as well.

The limiting values for the air we breathe and the water we drink are also based on these considerations. After all, zero pollution is not possible in today's conditions. As a matter of fact, the limits we use to access health now take into account coping with an environment full of pollution.

The algae currently taking over the Golden Horn is called phytoplankton, a class of green aquatic plants. It produces oxygen through photosynthesis. According to the scientific assessments, one of every two breaths that we take comes from these plants that live at the bottom of seas and oceans. They are also a source of food for many other organisms, thus an important element of the food chain.

These include the group known as cyanobacteria, a type of photosynthetic bacteria. They photosynthesize and need sunlight. The rising global temperatures are an advantage for them. However, temperature alone is not enough, and they also need sustenance, which could be a natural mineral found in the environment or a different source. In this case, the food source is essentially pollution, organic pollution containing nitrogen and phosphorus.

The oxygen in the environment is depleted as a result of overproliferation. They die, forming an unpleasant layer of dead carcasses on the surface of the water that then prevents sunlight from penetrating into the water. Other creatures that need light die. Oxygen in the water decreases over time. As a result, nothing can live there.

It negatively affects the fishing industry, getting wrapped up in nets and damaging boat engines. This has all happened before.

This event is more common in gulfs, bays and coastal regions and occurs all the time in some places. However, this has not happened in the Golden Horn for 25 years. So, what has changed to give rise to this?

Is it just a result of global warming? We know that it is not enough on its own. Also, food is needed for breeding and reproduction. Temperatures were extremely high in previous years as well. According to NASA records, 2016 was the year rising temperatures were most felt due to climate change. So, the hottest year in history was 2016. Again, 2019 was the second-hottest year in history. However, the Golden Horn did not witness algae blooms during these years. Maybe there was no food.

That is to say, now there is food. Although we call them nutrients, those who consume them are called unicellular beings, bacteria and cyanobacteria. As with other microorganisms, their main task is to decompose waste and maintain the natural balance and ensure the continuation of life. So, basically we are talking about pollution. The source of this food may be domestic wastewater containing detergents, industrial wastewater or surface water coming from agricultural fields. Likewise, agricultural fertilizers and pesticides rich in phosphorus and nitrogen can also lead to algae blooms.

Because the waters were regularly treated, the Golden Horn did not witness algae bloom for years. Treatment capacities and regulations were changed. Prior to 1994, only 9% of the wastewater in Istanbul was treated, and this was done only by removing rough pollution. As of 1994, new facilities were built and biological and advanced biological treatments were commissioned. Currently, 99% of it is being treated, and almost half of it goes through biological treatment. Cleaner wastewater is being released into the Bosporus and the Marmara Sea than in the past.

Frequent event

Algae blooms are a common phenomenon in our country and in the world, especially in bays. However, the situation can be temporary due to currents in the seas.

However, it is not a natural situation that develops spontaneously. It is usually an indication of pollution. It is nature's alarm system. It implies the area is getting dirty and that precautions are needed.

If pollution is continuous, this situation will not be temporary. Sporadic outbreaks indicate that the environment can tolerate incoming pollution and can repair itself, depending on the pollution load. However, in areas where pollution is constant and currents cannot help the water renew itself, it causes bigger problems.

Common challenge

The environment cannot be sacrificed for politics. It is unacceptable that the Golden Horn, refurbished through years of labor, be sacrificed. That would mean disrespecting years of labor, Istanbul and the people of Istanbul.

The environment is also a sensitive political issue. We consider the environment as preventive medicine. Investment in the environment is an investment in health: the more investments made, the lower the health costs. Therefore, environmental investments should be continuous, and you cannot claim that what you have invested so far would be enough.

That is why the ministry is playing an active role on the ground for the people and our future.

The ministry is not a mere spectator. First of all, we have to think about the health of our people, and this is what we are doing.

In fact, if the metropolitan municipality authorities had taken a few samples, measured and analyzed them instead of making excuses that it is "natural and temporary," it would be more convincing, as required by science. Indeed, actions speak louder than words.

Mind you, we are speaking on the basis of information and documents, separate from the politics of perception. We see the environment as an issue above politics.

Even this is an indication we are addressing the issue as more than simply political. Otherwise, we would leave them to their own devices and watch them lose their reputation in the public eye. But the environment is at stake.

Our call to the municipality

Instead of trying to appease the public by claiming that the situation is "natural and temporary," the Istanbul Metropolitan Municipality administration should act in accordance with science. They should take samples themselves to determine whether there has been a change in the area, revealing whether the incident is natural or fed by pollution. If the source of pollution is not dealt with, this will happen again and again.

Otherwise, more than 40 fish species and many other aquatic creatures will be forced to leave the area. This would set the Golden Horn's environmental state back 25 years. We expect the current administration to take steps to support past investments.

Finally, some claim that the algae are useful as they are part of the food chain and produce oxygen. This may be the case for the open sea and oceans, but the cyanobacteria that lead to this situation produce toxic secretions and block sunlight from penetrating the water's surface. They are harmful. If they were beneficial, we could simply not treat wastewater, dump pollution into the seas and let the algae increase; nevermind million dollars in investments. Is there any country that does this?

No, there are none, and there should never be nations with this mentality. We are bound by our obligation to future generations to protect the environment and to make decisions based on scientific findings and data. We also issued a warning about this issue around six months ago. We were right, but I wish we hadn't been. I would like to reiterate that the transformation of an estuary like the Golden Horn was difficult, but allowing its deterioration would be easy if a passive stance were taken. Let us not let that happen. It would benefit no one.

* Deputy minister at the Republic of Turkey's Ministry of Environment and Urbanization, chief climate change envoy