Madagascar, officially the Republic of Madagascar, is an island country lying off the southeastern coast of Africa. It is the world's fourth largest island, the second-largest island country and the 46th largest country in the world. Its capital and largest city is Antananarivo.

Madagascar consists of an eponymous main island and numerous smaller peripheral islands. Following the prehistoric breakup of the supercontinent Gondwana, Madagascar split from Africa during the Early Jurassic, around 180 million years ago, and split from the Indian subcontinent around 90 million years ago, allowing native plants and animals to evolve in relative isolation; consequently, it is a biodiversity hotspot and one of the world's 17 megadiverse countries, with over 90% of wildlife being endemic. The island has a subtropical to tropical maritime climate.

Blue Ventures was founded in southwest Madagascar in 2003, and historically the majority of its operations have been focused along the south, west and northwest coasts of the island. Its national headquarters is located in the capital Antananarivo, and there are five regional offices (in Ambanja, Andavadoaka, Belo-sur-Mer, Maintirano, and Toliara) linked to the organisation's programme sites. Blue Ventures' longest running marine expeditions programme is based in Andavadoaka in the southwest.

Blue Ventures is working towards a future where Madagascar's coastal zone is managed effectively by local fishing communities with the support of the government and other actors, thereby providing resilient livelihoods and food security for coastal people, while improving both human and ecosystem health. At priority conservation sites, it supports communities in developing solutions to local challenges and incentive-based models. Once they identify which approaches can be replicated, Blue Ventures then collaborates with ipartners both nationally and internationally to facilitate the wider uptake of these models and develop learning networks that can sustain them.

Blue Ventures' aquaculture programme supports communities to diversify their livelihoods by developing profitable sea cucumber and seaweed farms as a way of reducing fishing pressure and alleviating poverty. Since their community-based aquaculture programmes were established, more than 700 people have been trained to farm sea cucumbers and seaweed. Over half of these are women, for whom alternative income sources are limited.

Blue Ventures develops models for community-based aquaculture in which farms are owned and operated by community members. The organisation's aquaculture teams provide materials and technical guidance, and assist the farmers with start-up costs.

Blue Ventures also facilitates small business development with training programmes that build the technical, financial and organisational skills needed by fishers to manage their aquaculture businesses for the long term.

Isolated coastal communities face a range of interlinked social and environmental challenges. Just as a lack of transport infrastructure can prevent access to seafood markets, it can also prevent community members accessing essential health and family planning services. To improve access, Blue Ventures initiate a community health programme, known locally as Safidy, which means "choice" in Malagasy.

Safidy contributes to Blue Ventures' holistic People, their Health and the Environment (PHE) approach to conservation and development, which aims to generate long-lasting positive economic, social and ecological change. PHE entails the integration of family planning and other community health services with natural resource management, biodiversity conservation and alternative livelihood initiatives

In 2017, in partnership with Madagascar's Ministry of Health and other private health organisations like USAID, Mikolo and Mahefa Miaraka, Blue Ventures' community health team, collaborated in training and supporting community health workers across three regions in Madagascar (Atsimo Andrefana, Menabe, and Melaky) in order to provide family planning, maternal and child health, and water, sanitation and hygiene (WASH) health services. This will expand into the Ambanja region in the northwest of Madagascar.

Blue Ventures ran volunteer expeditions to Madagascar, Belize and Timor-Leste, for international volunteers and for school and university groups. Expeditions halted in 2020 as a result of the coronavirus pandemic. Its volunteer programme received numerous awards within the tourism sector, and was praised by Simon Reeve of the BBC's Indian Ocean with Simon Reeve series.

A central component of Blue Ventures' tourism activities was the community homestay, which offered a way for coastal communities to reap direct economic benefits from tourism.

Despite the deforestation trend, tree cover is increasing in some parts of the country, though largely of introduced (non-native) species such as Eucalyptus (various species), pine (Pinus kesiya, Pinus patula,) silver wattle (Acacia dealbata), silky oak (Grevillea banksii), and paperbark/niaouli ("Melaleuca quinquenervia"). Some of these trees are planted by foresters and farmers; others have become invasive of their own accord. Reforestation by eucalypts, pines, and wattles has been demonstrated, for instance, in the central highlands.

The ecoregions of Madagascar, as defined by the World Wildlife Fund, include seven terrestrial, five freshwater, and two marine ecoregions. Madagascar's diverse natural habitats harbour a rich fauna and flora with high levels of endemism, but most ecoregions suffer from habitat loss.

Madagascar's varied fauna and flora are endangered by human activity. Since the arrival of humans around 2,350 years ago, Madagascar has lost more than 90 percent of its original forest. This forest loss is largely fueled by tavy ("fat"), a traditional slash-and-burn agricultural practice imported to Madagascar by the earliest settlers. Malagasy farmers embrace and perpetuate the practice not only for its practical benefits as an agricultural technique, but for its cultural associations with prosperity, health and venerated ancestral custom (fomba malagasy). As human population density rose on the island, deforestation accelerated beginning around 1,400 years ago. By the 16th century, the central highlands had been largely cleared of their original forests. More recent contributors to the loss of forest cover include the growth in cattle herd size since their introduction around 1,000 years ago, a continued reliance on charcoal as a fuel for cooking, and the increased prominence of coffee as a cash crop over the past century. Madagascar had a 2019 Forest Landscape Integrity Index mean score of 4.63/10, ranking it 119th globally out of 172 countries.

According to a conservative estimate, about 40 percent of the island's original forest cover was lost from the 1950s to 2000, with a thinning of remaining forest areas by 80 percent. In addition to traditional agricultural practice, wildlife conservation is challenged by the illicit harvesting of protected forests, as well as the state-sanctioned harvesting of precious woods within national parks. Although banned by then-President Marc Ravalomanana from 2000 to 2009, the collection of small quantities of precious timber from national parks was re-authorized in January 2009 and dramatically intensified under the administration of Andry Rajoelina as a key source of state revenues to offset cuts in donor support following Ravalomanana's ousting.

Invasive species have likewise been introduced by human populations. Following the 2014 discovery in Madagascar of the Asian common toad, a relative of a toad species that has severely harmed wildlife in Australia since the 1930s, researchers warned the toad could "wreak havoc on the country's unique fauna." Habitat destruction and hunting have threatened many of Madagascar's endemic species or driven them to extinction. The island's elephant birds, a family of endemic giant ratites, became extinct in the 17th century or earlier, most probably because of human hunting of adult birds and poaching of their large eggs for food. Numerous giant lemur species vanished with the arrival of human settlers to the island, while others became extinct over the course of the centuries as a growing human population put greater pressures on lemur habitats and, among some populations, increased the rate of lemur hunting for food. A July 2012 assessment found that the exploitation of natural resources since 2009 has had dire consequences for the island's wildlife: 90 percent of lemur species were found to be threatened with extinction, the highest proportion of any mammalian group. Of these, 23 species were classified as critically endangered. A 2023 study published in Nature Communications found that 120 of the 219 mammal species only found on Madagascar are threatened with extinction.

In 2003, Ravalomanana announced the Durban Vision, an initiative to more than triple the island's protected natural areas to over 60,000 km² (23,000 sq mi) or 10 percent of Madagascar's land surface. As of 2011, areas protected by the state included five Strict Nature Reserves (Réserves Naturelles Intégrales), 21 Wildlife Reserves (Réserves Spéciales) and 21 National Parks (Parcs Nationaux). In 2007 six of the national parks were declared a joint World Heritage Site under the name Rainforests of the Atsinanana. These parks are Marojejy, Masoala, Ranomafana, Zahamena, Andohahela and Andringitra. Local timber merchants are harvesting scarce species of rosewood trees from protected rainforests within Marojejy National Park and exporting the wood to China for the production of luxury furniture and musical instruments.

Mid-2021 marked the beginning of the 2021–2022 Madagascar famine which, due to a severe drought, caused hundreds of thousands of people to face food insecurity and over one million people were on the verge of a famine.