Big Blue Conservation aims to protect the Koh Tao ecosystem in Thailand, and to inspire and build a global team of conservationists through education. As a marine conservation school, they actively contribute to pioneering marine research, with ongoing field research like diver-related reef damage, the impact of discarded nets on the reefs, and the recovery of corals from mass bleaching events. With a team dedicated to such scientific research, they work at formulating the policies and guidelines required to protect coral reefs for the future.

With offices in Australia, France, Germany, Ireland, UK, USA, Biosphere Expeditions is an award-winning wildlife conservation volunteering organization. They organize volunteering opportunities around the world, including marine conservation eg. turtle conservation in Costa Rica, Whale dolphin and turtle conservation in the Azores, Portugal, coral reef conservation in Oman, to name a few.

Biosphere Foundation's aim is promoting intelligent use of resources, and runs several specific projects related to land, space and sea. They are based in the USA with operations in Indonesia managed by PT Biosphere Stewardship Center and a partnership with Yayasan Biosfir Indonesia to work in Bali Barat National Park. The foundation has a four pronged approach:- Research, Education, Community, and Policy. Amongst their current focus projects is coral restoration.

BLOOM works to preserve the marine environment and species from unnecessary destruction and to increase social benefits in the fishing sector. In keeping with the mission to protect the oceans with concrete solutions, BLOOM conducts highly visible awareness and advocacy campaigns, informing the public, companies, institutions and leaders. Their research and evaluations highlight critical issues, such as the financing mechanisms of the fishing sector, destructive fishing methods such as electric pulse fishing. Their advocacy includes campaigning for protection of sharks and rays, and sustainable fishing. 

With a network of grassroots individual citizen activists, the Blue Frontier Campaign works towards the improvement of ocean policies in the 23 coastal states of the United States. According to Blue Frontier Campaign, the mission of the initiative is to construct the solution-oriented citizen engagement required to save our ocean, coasts and the communities. The initiative conducts regional meetings, public education campaigns and publishes books to achieve their goal. The campaign was founded by award-winning author and journalist David Helvarg in 2003. Blue Frontier works to support seaweed (marine grassroots) efforts at the local, regional and national level, with an emphasis on bottom up organizing to bring the voice of citizen-activists into national decision-making that will impact our public seas.

The aim of Blue Marine Foundation (BLUE) is 'to combat over-fishing and the destruction of biodiversity – arguably the largest problem facing the world’s oceans – by delivering practical conservation solutions, including the creation of large-scale marine reserves.' This includes sustainable fisheries which will allow fish stocks to recover. Their reach includes the UK, St Helena, Maldives, Aeolian Islands, Ascension Islands, Caspian Sea, Namibia, Patagonia and Tristan da Cunha, amongst others, and includes seagrass revegetation, protection of kelp forests, aquaculture and the blue economy in a drive to protect marine life and the communities dependent on it.

Blue Ocean Society works to protect marine animals and their habitats in the Gulf of Maine, through a variety of research and education programs. In their efforts to make facts about the marine life of the Gulf of Maine more accessible to the general public, the Blue Ocean Society regularly gives presentations on marine life to schools and libraries (followed by beach clean-up trips). They have also partnered with a number of reputable whale tour operators in the area to organize wild whale watching tours.

Blue Resources Trust is a marine research and consultancy organisation based in Sri Lanka that aims to promote informed science based decision making to facilitate the sustainable use of marine resources. Their past and current research has focused on coral reefs, fisheries, sustainable livelihoods, marine protected areas, and the development of domestic and international marine policy. They consult in a wide range of marine related fields including field surveys, EIAs, technical advice, and project management. In addition, they facilitate underwater photographers and film crews.

Blue Seas Protection is a marine conservation charity with the multiple missions of addressing climate and environmental issues, political campaigning, education and awareness about marine conservation, and direct action, working at all levels, from global and national Government campaigns, to local "boots on the ground" community projects. Their main activities are aimed at: Combatting overfishing (via advocacy, the Seaspiracy petition, and working with local fisheries), combatting marine pollution (via their Operation Sea Sweep programme and beach cleanups), education and awareness (via their SharkLab programme and outreach), the protection of marine species (including their BSP Marine Mammal Medics for local incidents), and their Marine Crime Watch monitoring and reporting system.

Blue Ventures works at catalysing and sustaining marine conservation projects led by locals in places where the ocean is vital to local cultures and economies, and are committed to protecting marine biodiversity in ways that benefit coastal people. Based in the UK, they operate in Madagascar, Mozambique, Somalia, Tanzania, Comoros, Kenya, Belize, India, Indonesia, Papua New Guines (PNG), Philippines, Thailand and Timor-Leste. In Madagascar they have created the largest LLMA (Locally Managed Marine Area) in the Indian Ocean. Amongst their many projects, their aquaculture projects include growing seagrass and sea cucumbers. At the same time they offer volunteering opportunities. Blue Ventures is increasingly active in all facets of marine conservation, and highly effective in achieving positive change in local communities.

Blue World was formed with the intention to take over the research and public awareness actions of the Adriatic Dolphin Project (ADP) started in 1987 and managed by the Tethys Research Institute until 2000. Blue World was created in 1999 by ten founders, mostly local but all involved in the ADP during previous years. Presently, Blue World carries out projects including Adriatic Dolphin Project, Losinj Dolphin Reserve, Losinj Marine Education Centre, Research and conservation of marine turtles of the Adriatic in cooperation with the Croatian Natural History Museum. Blue World actively cooperates with a number of organisations and institutions in Croatia and abroad. scientific research and conservation projects and promote environmental awareness in the Losinj-Cres archipelago, Croatia and Adriatic region as a whole.

Blue Voice is an ocean conservation organization founded in 2000 by Hardy Jones and Ted Danson, with the mission to protect dolphins, whales and other marine mammals, and to raise popular awareness about the plight of the oceans. After Harvey Jones died in 2018, the Hardy Jones Rapid Response Fund was created in his memory as a dedicated fund to support front-line activists and campaigners by the speedy disbursement of funds from time to time. Amongst other activities, they document transgressions against marine life on film.