River sanctuaries help giant fish recover in Southeast Asia

National Geographic –

It may run through a region riven by conflict, but western Thailand’s Ngao River, near the troubled border with Myanmar, is a peaceful haven to the more than 50 species of fish living in it. Below Ban Luiy, one of the many villages dotting the hillsides of this meandering river valley, scores of blue mahseer, a type of carp, congregate in crystal clear waters while a group of children splash nearby.

Fishing is not allowed here, or, more specifically, not in the stretches of river set up as protection zones. Ban Luiy was the first village to establish such a reserve 25 years ago, protecting about 1,000 yards of the more than 40-mile-long Ngao River as it runs past the settlement before eventually joining Myanmar’s Salween River, the largest undammed river in Asia. Over time, other villages followed suit, setting up their own fish sanctuaries of varying sizes. Today, there are 52 independently operated fish reserves on the Ngao River and its tributaries.

Five years ago, Aaron Koning, an aquatic ecologist with Cornell University’s Atkinson Center for a Sustainable Future, began studying the effects of those reserves on fish populations. Although river reserves are widespread in Southeast Asia, their impact has rarely been studied in Thailand or elsewhere in the region. Would the reserves, covering only short stretches of the river, really help protect large, migrating fish that may use an entire river system, he wondered.

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