Chumbe Island Coral Park is a private nature reserve off Zanzibar which includes a protected coral reef sanctuary, forest reserve and eco-lodge accommodation. Revenues generated by the reserve support the protection of the island and an education program.

CIIMAR hosts 10 research groups, organized in 3 research lines, with a scientific staff of more than 400 researchers with diverse backgrounds. Through the integration of different disciplines, the centre aims to contribute to the understanding of the processes which occur in the ocean and the coastal zones, for the sustainable use of aquatic resources and the evaluation of the impact of human activities on ecosystems. Their NetTag project aims to reduce and prevent marine litter derived from fisheries, bringing together scientists, engineers and the fisheries industry. The NetTag team has designed and produced a new technological device, currently under testing phase, for the location and recovery of fishing gear under water.

Citizens of the Great Barrier Reef has evolved into a key body of mobilization and cooperation of conservation action for the Great Barrier Reef. It has raised the profile of the GBR, empowering people with knowledge, experience, and ability to protect and enjoy the Reef, driving and communicating positive action with tangible in protecting the area which is under significant pressure.

Clean C's focus is on beach clean-ups. With the tagline, Community, Coastline, Cape Town, Country, they aim at Community upliftment through community involvement.

Clean Coast Bonaire organizes monthly coastal clean ups combined with citizen science, using the OSPAR Marine Litter Monitoring protocol to collect data along with marine debris. Cleanups are generally scheduled for the 2nd Sunday of the month, with volunteers collecting and analysing the litter washed up on the island's beaches and coves. Initiated in 2018 by Boneiru Duradero and WWF-NL, Clean Coast Bonaire participates in regional conversations regarding harmonization of marine litter monitoring. See the website for further info about the work being done co-ordinating this ongoing effort to combat marine litter.

Clean Coasts engages communities in the protection of Ireland’s beaches, seas and marine life. The programme is operated by the Environmental Education Unit of An Taisce and is currently funded by the Department of the Housing, Planning, Community & Local Government and Fáilte Ireland. Clean Coasts is made up of two main elements; Clean Coasts Volunteering and the Green Coast Award. They organize 100s of beach clean-ups each year, with thousands of volunteers, removing large quantities of marine litter from the coastline, and generally promote and facilitate clean-ups and marine litter surveys.

Since 1984, Clean Ocean Action (COA) has worked and continues to work to stop ocean pollution in the US, specifically in the waters off the New Jersey and New York coast. This includes campaigns against identified source of pollution, and advocating for environmentally sound solutions. Their campaigns are aimed at reducing plastics, litter and toxins that pollute waterways and beaches and which affect marine life, protecting the coast from oil and gas drilling in the ocean, and raising awareness of the issues. It is a broad-based coalition of 125 active boating, business, community, conservation, diving, environmental, fishing, religious, service, student, surfing, and women's groups, known as "Ocean Wavemakers".

Started by two teenagers in 2019, CleanSea's mission is clean the oceans and so to preserve marine life. This they do by removing trash from the ocean along Sweden's west coast, via coastal clean-ups, collecting plastic floating in marinas and sometimes diving to pull trash from the ocean floor. 22 000 kgs removed thus far (June 2022)

Clean Sea Life was an awareness raising program on marine litter uniting all marine enthusiasts in Italy – divers, yachtsmen, fishermen, beach goers, students and citizen – in the protection of the Mediterranean sea. It was started in 2016, with an end date of 2021. The project team engaged 170 000 people in clean up and dissemination activities, over four years. Nearly 1 000 clean-up operations were organised, both large and small, of which half were organised by stakeholders themselves, along with around 1 000 dissemination events. The project team organised several large events to clean beaches and the seafloor, and a huge quantity of waste and plastic garbage was removed (about 112 tons).

Clean Surf Project creates awareness to the devastating cause of littering especially plastic and polystyrene products and the impact it has on our ocean life. They organize beach cleanups

Clean Up Australia Limited is an Australian environmental conservation organisation. An avid sailor, Ian Kiernan AO was shocked and disgusted by the pollution and rubbish that he continually encountered in the oceans of the world, and established Clean Up Australia, to stop plastic and other pollution ending up in the sea.

Clean Water Action is an environmental advocacy group, which focuses on canvassing and gaining support for political issues and candidates who support the concerns of the group. Their mission is 'to secure clean, safe and affordable water; prevention of health threatening pollution; creation of environmentally safe jobs and businesses; and empowerment of people to make democracy work.'