Bosporus, one of the busiest waterways in the world, faces another danger other than possible ship accidents: pollution.
Clean-up work by Istanbul municipality's special boats equipped with industrial cleaning equipment, collected about 4,000 cubic meters of garbage in one month.
"This is enough to fill four football pitches," Fatih Polat Timur, the municipality's director of department fighting maritime pollution, says, pointing out the dire danger the waterway faces.
Nine boats staffed by 186 crew members regularly comb an area of 5 million square meters for garbage discarded by an inconsiderate public. Roughly 110 cubic meters of garbage is collected daily. Timur says it is a significant amount that lays bare how pollution threatens the Bosporus.
"We found everything from cellphones and computers to beds, TVs and motorcycles," Timur said.
Materials found beneath the sea were on display at a recent exhibition at city's famed Eminönü Square to raise awareness on the matter.
Plastic waste remains the primary threat to the waterway, particularly for the fish calling it home.
"Ghost fishing also poses a danger," Timur said, pointing out to plastic fishing nets and other fishing equipment abandoned or stuck at the bottom of the sea. Though it is difficult to monitor garbage thrown by individuals, authorities are able to monitor pollution by vessels crossing the Bosporus. Turkey recently updated its laws on maritime pollution, bringing heavier fines for polluting vessels.
For its part, Istanbul municipality reaches out to the public to educate them on the dangers of pollution to the ecosystem of the waterway.
Since 2017, the municipality's maritime services director, educated some 5,000 students in seminars about the pollution and urged them not to throw garbage into the sea.
"Cleaning is more expensive and difficult than getting people not to pollute the sea," Timur said.
Last year, Turkey took the first step for a massive campaign against plastic waste with zero waste campaign which aims to boost recycling and sorting the garbage, a trend which came late to the country. Starting from January, shops will be mandated to sell plastic bags instead of giving out them for free while municipalities started handing out free recyclable bags to citizens.
Environment and Urban Planning Minister Murat Kurum said every Turkish citizen uses 440 plastic bags yearly and they aim to reduce the number of plastic bags in the next five years.