Volunteer divers collected more than 130kg of rubbish in a single day in the waters off Abu Dhabi's Lulu Island.
Conservation organisation Azraq said the debris was mostly plastic bottles and fishing gear.
They were helped by ‘The Captain’s Club’, which provided a boat and captain for the clean-up.
Natalie Banks, founder of Azraq, said the collaboration will give volunteers regular access to boats to expand on its coral reef survey programme in Abu Dhabi, and possibly expand to Dubai.
“There is a great deal of debris on the sea floor, which I see regularly as a scuba diving instructor," she said.
"To conserve and protect our local waterways, we need to not only look at stopping the debris from entering the waterways, but assist to remove it also."
Azraq, founded in 2018 to help with the protection, defence and conservation of marine life, has organised a number of beach clean-up days with volunteer members.
However, it's the ocean cleans that are offering greater reward for effort, with larger amounts of debris found, according to Ms Banks.
“Organising the removal of debris from the seabed requires a great deal of organisation and logistics, and we could not be happier with the support that The Captain’s Club provides us,” Ms Banks said.
"We are also extremely grateful for the support from the Environment Agency Abu Dhabi and Tadweer, which sent a boat to Lulu Island to collect the debris afterwards.”
Last week, Environment Agency Abu Dhabi collected about 200kg of fishing gear, nets and plastic from Al Bahrani Island and the surrounding waters.
While the agency said there were no hazardous chemicals or waste found, it reminded the public of the dangers that plastic waste poses to marine life.
“Plastics are non-degradable materials that cause long-term impacts to marine wildlife and the environment,” the agency said.