The Mangrove maniacs is a group of volunteers and professionals dedicated to open up the channels in the mangrove forest of the Lac area on Bonaire. Bonaire hosts the largest mangrove forest within the Dutch Caribbean. These forests are extremely important for many reasons, including biodiversity, water quality, marine life, carbon sequestration, and yet are under under threat due to over development and increased pressures of climate change. This group works to protect these areas through building resilience to ensure the mangroves thrive, including by outplanting new mangroves, ensuring the flow through channels in the forest, and supporting conservation research.

Mangroves for the Future (MFF) is a partnership-based regional initiative which promotes investment in coastal ecosystem conservation for sustainable development. MFF focuses on the role that healthy, well-managed coastal ecosystems play in building the resilience of ecosystem-dependent coastal communities in Bangladesh, Cambodia, India, Indonesia, Maldives, Myanmar, Pakistan, Seychelles, Sri Lanka, Thailand and Viet Nam. The initiative uses mangroves as a flagship ecosystem, but MFF is inclusive of all types of coastal ecosystem, such as coral reefs, estuaries, lagoons, sandy beaches, sea grasses and wetlands. MFF is co-chaired by IUCN and UNDP. Confirmation required whether MFF is still active (July 2022)

Manta Matcher is a global online database for manta rays. It is one of the Wildbook Web applications developed by Wild Me, created in partnership with Dr. Andrea Marshall of the Marine Megafauna Foundation. Manta rays have unique spot patterning on their undersides, which allows for individual identification. Scuba divers upload their manta identification photographs to the Manta Matcher website, supporting global research and conservation efforts. Manta Matcher is a pattern-matching software. This citizen science tool is free to use by researchers worldwide.

The Manta Trust was formed in 2011 to co-ordinate global research and conservation efforts for manta rays, their close relatives and their habitat. The Trust brings together a number of projects from around the globe, both new and long-standing, including the Republic of Maldives, Sri Lanka, Mexico and Indonesia. They conduct studies into manta populations in these locations, thus providing the information needed by Governments, NGO’s and conservationists can make decisions to ensure the long term survival of these animals and their habitat.

The MAR Fund (Mesoamerican Reef Fund) was established in 2004 by representatives from conservation funds in the countries of the MAR region (Belize, Guatemala, Honduras, and Mexico) as a regional funding and coordination institution. It is a private fund intended to drive regional funding and partnerships for the conservation, restoration, and sustainable use of the Mesoamerican Reef. This includes: Saving our Sanctuaries (supports the establishment and protection of an interconnected network of priority coastal and marine protected areas in the region), Fishing for the Future (sustainable fisheries and the establishment of fisheries recovery areas) and Climate Change: The Need is Now (monitoring climate change effects on the reef and supporting adaptation to climate change).

Mar Sustentable is a marine conservation organization focused on scientific research and education. Their scientific mission is to collect 'data on coastal exploitation and socioecological systems to integrate the ecological, social, archaeological, and physical dimensions of coastal environments', while their environmental education mission is aimed at creating awareness in order that individuals and communities make changes for a healthier “planet ocean”.

MarAlliance is an international non-governmental organization that ‘designs and conducts collaborative grassroots research and conservation action on threatened marine megafauna such as sharks, rays, turtles and large finfish. Working with fishers and other key stakeholders of the sea, (they) generate essential data on megafauna populations, behaviour and ecology to enable fact-based conservation and management’. The organization supports the creation and expansion of marine protected areas and legislation that enables sustainable fisheries to minimize threats and maximize protection of sharks and rays. MarAlliance is registered in the US (California) and locally in Belize, Panama and Cabo Verde. They work remotely from multiple bases in the US, Belize, Honduras, Panama, Cabo Verde and Micronesia.

Set up by Marine Biological Association of the UK, MarLIN is a resource which provides information for marine conservation, management, protection and planning, a centre of excellence in spatially based and time-series marine biological information and for good stewardship in the marine environment. The resources are based on available scientific evidence and designed for all stakeholders, from government agencies and industry to naturalists and the public. MarLIN hosts the largest review of the effects of human activities and natural events on marine species and habitats yet undertaken.

Based in Costa Rica, Panama and Columbia, MarViva Fundación is a regional, non-governmental and non-profit organization, whose area of ​​action is located in the Eastern Tropical Pacific, and which has the aim of conservation and sustainable use of marine and coastal resources through the management of human activities at sea.

Part of the municipal initiative to keep the sea and beaches clean, the Ecolmarine team, with 14 boats, remove scum from surface and remove solid items

MareCet is dedicated to the research and conservation of marine mammals in Malaysia. Established in 2012 and run by researcher-conservationists, they focus on increasing scientific knowledge through research, conservation-based outreach and education, strengthening policies, and developing capacity for this field of work. MareCet strives to work to protect marine mammals and their fragile habitats, provide a platform for building local conservation leadership talent, work with stakeholders to optimise conservation outcomes for all involved, and promote ocean stewardship within society at large in Malaysia.

An environmental research and conservation organization, MareTerra studies the natural life around Sardinia. This includes monitoring populations (in particular dolphins) to assess the impact of human activity on their conservation status. Most of their present research and monitoring programs are carried out between the northernmost point of the island and the southern coast of the small town of Bosa. 'Part of this area is protected by national and international laws for its remarkable naturalistic and geological relevance'. Education and guiding eco-tourism within the area is an important part of their mission.