Freshwater fisheries conservation can increase biodiversity

RESEARCH ARTICLE Freshwater fisheries conservation can increase biodiversity Declan Butorac1, Paulo SantosID2*, Phousavanh Phouvin3, Francois Guegan4 1 Environmental Management, Monash University, Clayton, Vic, Australia, 2 Dept Economics, Monash University, Caulfield, Vic, Australia, 3 Dept of Fisheries, National University of Laos, Vientiane, Lao PDR, 4 WWF - Laos, Vientiane, Lao PDR * paulo.santos@monash.edu Abstract We evaluate the impact of a fisheries management program centered on the definition of Fish Conservation Zones on biodiversity, measured as the number of species caught in the last 12 months. Data comes from a set of 32 villages in central Lao PDR, of which half partic- ipated in the program, and the remaining are a set of matched control villages. The esti- mated causal effects are large (an increase between 29 and 32 species) and robust to the potential importance of unmeasured confounders. We also show that initial conditions may matter, as the program seems particularly effective in villages with high probability of partici- pating in the program. These results are particularly important given the paucity of evidence regarding the impact of conservation programs on biodiversity, particularly in the context of freshwater ecosystems. Further directions of research suggested by these results are discussed. Introduction There is a widely accepted recognition that freshwater ecosystems are extraordinarily rich in terms of biodiversity: representing approximately 2.3% of the global land surface, fresh waters

host approximately 9.5% of the described animal species [1]. It is also widely recognized that such richness is under disproportionately increased pressure, from both old and new threats [1, 2]. As a result the rate of decline in biodiversity in freshwater systems has outpaced that of terrestrial ecosystems [3, 4]. Adding to this diagnostic, there is also a suspicion that approaches to conservation adopted in terrestrial ecosystems, based on the definition of high habitat quality that can be well defined and bounded (“fortress conservation” in the words of [1]), are difficult to transfer to conserva- tion of freshwater systems: protection of a particular habitat may require control of upstream drainage areas and, if migratory behavior is important, also of the areas downstream. The whole catchment becomes the natural boundary, but conservation encompassing this scale is rare [5]. Perhaps reflecting these difficulties, there is only a small number of examples of fresh- water conservation initiatives relying on no-take areas: see, for example, [6] for Cambodia, [7] for the countries around Lake Victoria in east Africa, [8] for India, [9] for The Philippines and, PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0233775 May 27, 2020 1 / 14 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Butorac D, Santos P, Phouvin P, Guegan F (2020) Freshwater fisheries conservation can increase biodiversity. PLoS ONE 15(5): e0233775. https://doi.org/10.1371/journal.pone.0233775 Editor: Fabio de Oliveira Roque, Universidade

Federal de Mato Grosso do Sul, BRAZIL Received: December 11, 2019 Accepted: May 12, 2020 Published: May 27, 2020 Copyright: © 2020 Butorac et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All files are available from the DANS database (https://doi.org/10.17026/ dans-xcy-836v). Funding: PS acknowledges funding from the Australian Center for International Agricultural Research (ACIAR), through grant ASEM/2012/073. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: The authors have declared that no competing interests exist.