title: Impacts of Dams and Global Warming on Fish Biodiversity in the Indo-Burma Hotspot.
abstract: Both hydropower dams and global warming pose threats to freshwater fish diversity. While the extent of global warming may be reduced by a shift towards energy generation by large dams in order to reduce fossil-fuel use, such dams profoundly modify riverine habitats. Furthermore, the threats posed by dams and global warming will interact: for example, dams constrain range adjustments by fishes that might compensate for warming temperatures. Evaluation of their combined or synergistic effects is thus essential for adequate assessment of the consequences of planned water-resource developments. We made projections of the responses of 363 fish species within the Indo-Burma global biodiversity hotspot to the separate and joint impacts of dams and global warming. The hotspot encompasses the Lower Mekong Basin, which is the world's largest freshwater capture fishery. Projections for 81 dam-building scenarios revealed progressive impacts upon projected species richness, habitable area, and the proportion of threatened species as generating capacity increased. Projections from 126 global-warming scenarios included a rise in species richness, a reduction in habitable area, and an increase in the proportion of threatened species; however, there was substantial variation in the extent of these changes among warming projections. Projections from scenarios that combined the effects of dams and global warming were derived either by simply adding the two threats, or by combining them in a synergistic manner that took account of the likelihood that habitat shifts under global warming would be constrained by river fragmentation. Impacts on fish diversity under the synergistic projections were 10-20% higher than those attributable to additive scenarios, and were exacerbated as generating capacity increased-particularly if CO2 emissions remained high. The impacts of dams, especially those on river mainstreams, are likely to be greater, more predictable and more immediately pressing for fishes than the consequences of global warming. Limits upon dam construction should therefore be a priority action for conserving fish biodiversity in the Indo-Burma hotspot. This would minimize synergistic impacts attributable to dams plus global warming, and help ensure the continued provision of ecosystem services represented by the Lower Mekong fishery.
authors.affiliation: Institute of Decision Science for a Sustainable Society, Kyushu University, Fukuoka, Fukuoka, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kano
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: David
authors.initials: D
authors.lastname: Dudgeon
authors.affiliation: Inland Fisheries Research and Development Institute of Fisheries Administration, Phnom Penh, Cambodia.
authors.forename: So
authors.initials: S
authors.lastname: Nam
authors.affiliation: Institute for Global Environmental Strategies, Hayama, Kanagawa, Japan.|Department of Urban and Environmental Engineering, Kyushu University, Fukuoka, Fukuoka, Japan.
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Samejima
authors.affiliation: Department of Zoology, Kyoto University, Kyoto, Kyoto, Japan.
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Department of Fisheries, Ubon Ratchathani University, Ubon Ratchathani, Thailand.
authors.forename: Chaiwut
authors.initials: C
authors.lastname: Grudpan
authors.affiliation: Department of Fisheries, Ubon Ratchathani University, Ubon Ratchathani, Thailand.
authors.forename: Jarungjit
authors.initials: J
authors.lastname: Grudpan
authors.affiliation: Department of Biology, Mahasakham University, Maha Sarakham, Thailand.
authors.forename: Wichan
authors.initials: W
authors.lastname: Magtoon
authors.affiliation: Faculty of Fisheries, Kasetsart University, Bangkok, Thailand.
authors.forename: Prachya
authors.initials: P
authors.lastname: Musikasinthorn
authors.affiliation: Department of Fisheries Management and Economics, Can Tho University, Chan Tho, Vietnam.
authors.forename: Phuong Thanh
authors.initials: PT
authors.lastname: Nguyen
authors.affiliation: Faculty of Science, National University of Laos, Vientiane, Lao PDR.
authors.forename: Bounthob
authors.initials: B
authors.lastname: Praxaysonbath
authors.affiliation: Siem Reap Freshwater Fishes Laboratory, Siem Reap, Cambodia.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Sato
authors.affiliation: Nagao Natural Environment Foundation, Sumida, Tokyo, Japan.|Museum of Natural and Environmental History, Shizuoka, Shizuoka, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Shibukawa
authors.affiliation: Institute of Decision Science for a Sustainable Society, Kyushu University, Fukuoka, Fukuoka, Japan.|Department of Urban and Environmental Engineering, Kyushu University, Fukuoka, Fukuoka, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Shimatani
authors.affiliation: Faculty of Fisheries Technology and Aquatic Resources, Maejo University, Chiang Mai, Thailand.
authors.forename: Apinun
authors.initials: A
authors.lastname: Suvarnaraksha
authors.affiliation: Graduate Education and Research Training Program in Decision Science for Sustainable Society, Kyushu University, Fukuoka, Fukuoka, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Tanaka
authors.affiliation: Inland Fisheries Research and Development Institute of Fisheries Administration, Phnom Penh, Cambodia.
authors.forename: Phanara
authors.initials: P
authors.lastname: Thach
authors.affiliation: Department of Fisheries Management and Economics, Can Tho University, Chan Tho, Vietnam.
authors.forename: Dac Dinh
authors.initials: DD
authors.lastname: Tran
authors.affiliation: Institute of Decision Science for a Sustainable Society, Kyushu University, Fukuoka, Fukuoka, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Yamashita
authors.affiliation: Nagao Natural Environment Foundation, Sumida, Tokyo, Japan.
authors.forename: Kenzo
authors.initials: K
authors.lastname: Utsugi
mesh_terms: D000465:Algorithms; D000818:Animals; D001210:Asia, Southeastern; D044822:Biodiversity; D003198:Computer Simulation; D003247:Conservation of Natural Resources; D005398:Fisheries; D005399:Fishes; D005618:Fresh Water; D057232:Global Warming; D011210:Power Plants; D045483:Rivers