Tourism accounts for almost 70 percent of the Cook Islands’ economy, but the industry is proving extremely damaging to its delicately balanced island ecosystem, and is contributing to islanders’ detachment from traditional ways of life.Now, though, some tourism players, activists and government officials are pushing the industry to change tack in hopes it can start to sustain the island’s people and culture while protecting its ecology, too.Tourism operators are being asked to live up to the sustainability street cred that the country’s 2017 decision to designate its entire exclusive economic zone as a multiple-use marine protected area has granted it on the international stage. This story is part of a series on Marae Moana, the massive, recently enacted multiple-use marine protected area covering the Cook Islands’ entire exclusive economic zone. Other stories in the series: Building the world’s biggest MPA: Q&A with Goldman winner Jacqueline Evans Will a massive marine protected area safeguard Cook Islands’ ocean? Give it back to the gods: Reviving Māori tradition to protect marine life Cook Islands MPA leader fired after supporting seabed mining freeze RAROTONGA, Cook Islands — With its white sand, turquoise waters and train of dreamy desert islands just offshore, it’s not hard to see why Muri Lagoon hits the spot for holidaymakers. Situated on the east coast of Rarotonga, the largest and most populous of the Cook Islands, the lagoon is the biggest tourist attraction and collective revenue earner in the country. But in the spring of 2015, dark patches of noxious algal bloom began spreading across Muri Lagoon’s sandy floor, clouding up its famously clear water and prompting many visitors to turn up their nose at the prospect of diving in. A view of Muri Lagoon, Rarotonga. Image by Monica Evans for Mongabay. Why? Muri’s ebullient tourism sector had failed to deal appropriately with the waste left by those it welcomed. On Rarotonga, most people use septic tanks, which treat human waste to a basic level underground, then let it drain out through a septic drainage field or soak hole. But more than 90 percent of the businesses along Muri’s shore had non-compliant, substandard systems, and they proved woefully inadequate for the high number of visitors that year. Many of the systems had begun to leach nutrients into the lagoon, damaging its marine life and fueling the spread of the unsightly algae. Tourism makes up almost 70 percent of the Cook Islands’ economy and provides critical employment opportunities to counter out-migration trends. But the industry as it stands is proving extremely damaging to Rarotonga’s delicately balanced island ecosystem, and is contributing to islanders’ detachment from traditional ways of life. Now, though, some tourism players, activists and government officials are pushing the industry to change tack in hopes it can start to sustain the island’s people and culture while protecting its ecology, too.