Six tonnes of rubbish were pulled from the waters of Dubai's Deira district on Wednesday morning with the help of more than 200 volunteer divers.
Dubai Police's marine rescue department organised the initiative as part of broader efforts to clean up the Creek at the heart of the bustling market area.
Divers found dumped tyres among bags full of soft drink cans among a variety of waste.
The clean-up was held at Al Hamriya Port, close to the popular gold souk and the main water of the Creek, which has been the focus of regeneration in recent years.
Across the water is the new Deira Islands, a major new development by Nakheel that will see the arrival of hotel resorts, a water park and housing, and close-by is the cruise ship terminal, which last year welcomed 650,000 passengers on 157 ship calls.
Police said dhow crews and others contribute to the problem by dumping waste overboard, risking fines and damaging the environment in the process.
“Waste and plastic junk has a negative impact on the marine life. Sadly, plastic items, electrical tools, tyres, parts of vehicles and cans are being collected from underwater today," said Lt Col Ali Abdullah Al Naqbi, head of the maritime rescue department at Dubai Police.
"Fish and other creatures are all being affected by the litter. More than 50 tonnes are collected annually from Dubai waters.
“I had hoped that the amount of waste collected during this initiative is lower than last year. A total of four tonnes were collected in 2016 during the initiative."
Yumaima Salim Al Falasi, from Dubai Muncipality, singled out commercial vessels.
"For instance, owners of import and export ships with an excessive load will throw an amount into the sea, without thinking about the consequences. This is only one example of many," she said.
"When large quantities of waste are released into the sea, it will have a direct impact on the water. Imagine fish eating these substances and then we eat it. Preserving marine life is essential.
“What we have left for the next generation if we allow waste to be dumped into the water?"
Nasser Saleh Al Qersh, a volunteer diver, said the teams used balloon s to raise heavy items such as tyres. Two years ago, divers and the municipality raised an entire sunken dhow weighing about 100 tonnes.
"The waste comes from ships and boat owners. Some of the things that we find underwater are indescribable," said the Emirati accountant, aged 31.
He said the public may see rubbish on the surface but maybe unaware of the "massive impact it has on marine life" underneath the water.
Around the gold souk on Wednesday, local traders said it is not just marine vessels that are to blame.
Mohammed Yousef, an abra operator, said he had seen residents disposing of rubbish and paper in the water, despite the threat of a Dh500 fine.
Floating under Abdul Ghafar Mohammed's boat near Heritage Village was plastic water bottles and other rubbish.
“I always throw my waste in garbage. Otherwise, municipality will give me a hefty fine. But others might throw garbage into the water," he said.
Kenneth Freer, 68, a tourist from New Zealand who has been in the country for two days, said he "noticed the rubbish when I walked around" the heritage village.
"It will definitely affect the marine life," he said.
Lt Col Al Naqbi urged residents and visitors to respect the sea and the Creek. He also thanked the volunteer divers, who went into the water alongside the police rescue team.
"We organise the clean-up initiative in October because the weather is fine and temperatures go down. Police divers are used to working in the hot weather, but it can be hard for members of the public," he said, extending his thanks.