Functional responses of fisheries to hydropower dams in the Amazonian Floodplain of the Madeira River

1. Tropical river fisheries support food security for millions of people but are increasingly threatened by hydropower development. How dams affect these fisheries remains poorly known in most regions. Here, we used a functional traits approach to evaluate the extent to which the composition of fishery yields in the Madeira River Basin the largest sub-basin in the Amazon, respond to dam construction. We also explored how dams affected the monetary value of yields and fishing-based income of the communities.
2. We collected fishing data in 17 locations distributed more than 300 km across upstream, reservoir, and downstream zones during pre-and post-dam construction periods. We interviewed 711 fishers from 13 communities to assess fishing income during pre- and post-dam periods.
3. Catch-per-unit effort (CPUE) declined significantly, i.e., by 37%, after dam construction. Multivariate analysis yielded six species clusters according to trait syndromes related to life history, migration, swi..., Fishery data: The fishery data were collected by a monitoring program coordinated by the Ichthyology and Fisheries Laboratory of the Federal University of Rondônia that included 17 locations from November 2003 to February 2005, and again from April 2008 to November 2013 (Fig. 1, Table S2). This dataset consists of standardized interviews conducted with fishers on a daily basis after their return from fishing trips. Data from before closure of the dam, Nov- 2003 to Nov- 2011, represented pre-dam period and data from after closure of the dams, Dec- 2011 to 2013, represented post-dam construction, following Cella-Ribeiro et al. (2017). The data recorded included yield (total kg/fishing trip), taxon (common names of species, or of species group, Table 1), and effort (fishers/day) of fishing trips. We calculated catch-per-unit effort (CPUE) for every month (CPUE = monthly yields of fish divided by monthly fishing effort (Petrere et al., 2010) for each taxa group and period (pre- and post-dam..., This dataset contains the environmental data (seasonal hydrology and flooded area at buffer or floodplain scales, and the pre- or post-dam periods) (R table), and the CPUE of each taxon (L table).