Ecuador has sounded the alarm after its navy discovered a huge fishing fleet of mostly Chinese-flagged vessels some 200 miles from the Galápagos Islands, the archipelago which inspired Charles Darwin’s theory of evolution. About 260 ships are currently in international waters just outside a 188-mile wide exclusive economic zone around the island, but their presence has already raised the prospect of serious damage to the delicate marine ecosystem, said former environment minister Yolanda Kakabadse. “This fleet’s size and aggressiveness against marine species is a big threat to the balance of species in the Galápagos,” she told the Guardian. Kakabadse and an ex-mayor of Quito, Roque Sevilla, were on Monday put in charge of designing a “protection strategy” for the islands, which lie 563 miles west of the South American mainland. Chinese fishing vessels come every year to the seas around the Galápagos, which were declared a Unesco world heritage site in 1978, but this year’s fleet is one of the largest seen in recent years. Sevilla said that diplomatic efforts would be made to request the withdrawal of the Chinese fishing fleet. “Unchecked Chinese fishing just on the edge of the protected zone is ruining Ecuador’s efforts to protect marine life in the Galápagos,” he said. He added that the team would also seek to enforce international agreements that protect migratory species. The Galápagos Marine Reserve has one of the world’s greatest concentrations of shark species, including endangered whale and hammerhead varieties. Kakabadse said efforts also would be made to extend the exclusive economic zone to a 350-mile circumference around the islands which would join up with the Ecuadorean mainland’s economic zone, closing off a corridor of international waters in between the two where the Chinese fleet is currently located. Ecuador is also trying to establish a corridor of marine reserves between Pacific-facing neighbours Costa Rica, Panama and Colombia which would seal off important areas of marine diversity, Kakabadse said. Ecuador’s president Lenín Moreno described the archipelago as “one of the richest fishing areas and a seedbed of life for the entire planet”, in a message on Twitter over the weekend. The Galápagos Islands are renowned for their unique plants and wildlife. Unesco describes the archipelago – visited by a quarter of a million tourists every year – as a “living museum and a showcase for evolution”. The Ecuadorean navy has been monitoring the fishing fleet since it was spotted last week, according to the country’s defence minister Oswaldo Jarrín. “We are on alert, (conducting) surveillance, patrolling to avoid an incident such as what happened in 2017,” he said. The 2017 incident he referred to was the capture by the Ecuadorean navy within the Galápagos Marine Reserve of a Chinese vessel. The Fu Yuan Yu Leng 999, part of an even larger fleet than the current one, was found to be carrying 300 tonnes of marine wildlife, mostly sharks. “We were appalled to discover that a massive Chinese industrial fishing fleet is currently off the Galápagos Islands,” said John Hourston, a spokesman for the Blue Planet Society, a NGO which campaigns against overfishing.