Aaron Koning, a postdoctoral research fellow at the University of Nevada, Reno’s Global Water Center, has spent seven years studying a network of freshwater protected areas (fish reserves) that communities established in one branch of the Salween River Basin in northern Thailand.
Working with the communities that rely on the river, he established friendships and trust and gained important insights that helped in his work to study how freshwater reserves help both the fish in the river and the people whose daily lives revolve around the Ngao River the river of shadows.
In his most recently published research of this reserve network in Thailand, he found that the freshwater fish reserves are extraordinarily successful at protecting multiple species of fish. He mapped more than 50 reserves, all community organized and managed independently of government support, throughout the river and its branches.
The area supports more than 40 species of fish, ranging from large minnows to catfish to needlefish. The results were published Nov. 25 in the scientific journal Nature in the article A network of grassroots reserves protects tropical river fish diversity.
The conservation benefits of each reserve established independently by local Pgagayaw, or Karen, indigenous communities are remarkable, and the collective benefits for fish within the entire network of reserves are even greater, Koning said. Twenty-seven years ago, one community created a reserve in an effort to protect their fish, and since then reserves have spread among communities throughout the valley. It’s a great story of effective community-based resource management.
Koning worked with a team of scientists who he had known from his work at the University of Wisconsin-Madison: Martin Perales from the University of Wisconsin-Madison; Etienne Fluet-Chouinard, now from Stanford University, and aquatic conservation ecologist and Associate Professor Peter McIntyre of Cornell University.
During the six weeks of fieldwork related to this study, Martin and I lived with friends in riverside villages, but made the 90-minute drive to Mae Sarieng for internet access on a couple of weekends, The families we stayed with have been like my extended host family for the past seven years, with friends and relatives spread throughout the river valley.
They bounced around the study area of the 50-mile-long Ngao River in a 1999 Toyota Hilux 4X4 truck, through the various communities, including teak forests and upland agricultural areas with rice paddies and soybean crops.
When I initially started documenting the locations of reserves several years ago, I tried to find the locations of as many reserves within the basin as I could by exploring every road and trail on the map, and many that weren’t on any map, he said. For our fish surveys, we selected a set of 23 reserves distributed throughout the river basin that broadly represented all of the reserves. While there are probably 40 species within this river valley, in this study we regularly observed 33 species of fish.
His fish surveys were conducted during the dry season, when little or no rain falls from November to May. In the wet season, the river increases in height by more than 12 feet, everything is lush and damp and the teak and dipterocarp trees dominate much of the landscape along with as well as upland agricultural areas, rice paddies, and soybeans being grown.
Intensive fisheries have reduced fish biodiversity and abundance in aquatic ecosystems worldwide. No-take reserves have become a cornerstone of marine ecosystem-based fisheries management. The team used the knowledge gained from decades of study on marine reserves to test if the same principles of success might apply to this network of riverine reserves, where one might not think reserves would work.
The applicability of this marine reserve network paradigm to riverine biodiversity and inland fisheries remains largely untested, Koning said. Our research shows that freshwater reserves created by 23 separate communities in Thailand’s Salween basin have dramatically increased fish richness, density and biomass when compared to adjacent areas. One river reserve is 1,000 feet long and just 12 feet wide in dry season, but you can see fish everywhere.
Underwater fish surveys were done using masks and snorkels with lots of crawling over and around rocks underwater. In many reserves, the abundance and size of fish seeking protection was evident by eye from the river bank in the dry season.
McIntyre, now Koning’s colleague in this research, was once his doctoral advisor at the University of Wisconsin, and co-advisor for his postdoctoral work at Cornell. McIntyre said he was shocked that the reserves worked so well.
When you see piles of fish in each of these reserves, it is clear that something big is happening, he said. Questions remain about whether the fish populations are viable in the long run, and how durable the governance approach will prove, but this unique experiment in conservation still has much to teach us.
University of Nevada, Reno