One of the world’s largest marine protection areas has been created off the coast of Easter Island.

The 740,000 sq km Rapa Nui marine park is roughly the size of the Chilean mainland and will protect at least 142 endemic marine species, including 27 threatened with extinction.

An astonishing 77% of the Pacific Ocean’s fish abundance occurs here and recent expeditions discovered several new species previously unknown to science.

Apex predators found in the conservation zone include scalloped hammerhead sharks, minke, humpback and blue whales, and four species of sea turtle.

Matt Rand, the director of the Pew Bertarelli ocean legacy project, which campaigned for the park, said: “This marine reserve will have a huge global significance for the conservation of oceans and of indigenous people’s ways of life.

“The Rapa Nui have long suffered from the loss of timber, declining ecosystems and declining populations. Now they are experiencing a resurgence based on ensuring the health of the oceans.”

Plans for the marine park were first announced at a conference in 2015, at which the former US president Barack Obama declared his “special love for the ocean” in a video message.

The plans were confirmed in a speech by Chilean president Michelle Bachelet on Saturday.

The marine park’s creation was enabled by a 73% vote in favour of the conservation zone from Easter Island’s 3,000 Rapa Nui population in a referendum on 3 September, after five years of consultations.

Extractive industries and industrial fishing will be banned inside the reserve, but the Rapa Nui will be allowed to continue their traditional artisanal fishing on small boats, using hand lines with rocks for weights.

Ludovic Burns Tuki, the director of the Mesa del mar coalition of more than 20 Rapa Nui groups, said: “This is a historic moment – a great and beautiful moment for the Rapa Nui, for the world and for our oceans.

“We think this process can be an example for the creation of other marine reserves that we need to protect our oceans – with a respect for the human dimension.”

After the creation of a comparable marine protection area around the nearby Pitcairn Islands last year, proposals for a reserve in the Austral Islands’ waters could soon create a protected area of more than 2m sq km. This would have a unifying potential for the Polynesian people, according to Burns Tuki.

Approximately one-quarter of all fishes swimming in Rapa Nui are endemic, like the Pseudolabrus semifasciatus. Photograph: Luiz Rocha/California Academy of Sciences

“The ocean is very important to us as a source of food, but the Polynesians were great navigators and the ocean also represents our mother,” he said. “It enables us to move with a double canoe between the different islands. It gives us everything.”

As global warming takes hold, some scientific papers suggest that marine reserves may also help mitigate climate change and provide a vital carbon sink. The deep, clear and cool waters around Easter Island are also a resilient area for coral reefs.

Marcelo Mena, Chile’s environment minister, said: “This marine protected area adds to the legacy of President Bachelet and the 1.5m sq km of protected areas created by this government.”

The International Union for Conservation of Nature has called for 30% of the world’s oceans to be protected, but only about 1.6% has so far been covered by marine protection areas.