title: The imperiled fish fauna in the Nicaragua Canal zone.
abstract: Large-scale infrastructure projects commonly have large effects on the environment. The planned construction of the Nicaragua Canal will irreversibly alter the aquatic environment of Nicaragua in many ways. Two distinct drainage basins (San Juan and Punta Gorda) will be connected and numerous ecosystems will be altered. Considering the project's far-reaching environmental effects, too few studies on biodiversity have been performed to date. This limits provision of robust environmental impact assessments. We explored the geographic distribution of taxonomic and genetic diversity of freshwater fish species (Poecilia spp., Amatitlania siquia, Hypsophrys nematopus, Brycon guatemalensis, and Roeboides bouchellei) across the Nicaragua Canal zone. We collected population samples in affected areas (San Juan, Punta Gorda, and Escondido drainage basins), investigated species composition of 2 drainage basins and performed genetic analyses (genetic diversity, analysis of molecular variance) based on mitochondrial cytb. Freshwater fish faunas differed substantially between drainage basins (Jaccard similarity = 0.33). Most populations from distinct drainage basins were genetically differentiated. Removing the geographic barrier between these basins will promote biotic homogenization and the loss of unique genetic diversity. We found species in areas where they were not known to exist, including an undescribed, highly distinct clade of live bearing fish (Poecilia). Our results indicate that the Nicaragua Canal likely will have strong impacts on Nicaragua's freshwater biodiversity. However, knowledge about the extent of these impacts is lacking, which highlights the need for more thorough investigations before the environment is altered irreversibly.
authors.affiliation: Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Härer
authors.affiliation: Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany.|Zukunftskolleg, University of Konstanz, Konstanz, Germany.
authors.forename: Julián
authors.initials: J
authors.lastname: Torres-Dowdall
authors.affiliation: Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Meyer
mesh_terms: D000818:Animals; D044822:Biodiversity; D003247:Conservation of Natural Resources; D056727:Endangered Species; D005399:Fishes; D009527:Nicaragua; D010177:Panama Canal Zone
keywords: América Central; Central America; Poeciliidae; biodiversidad de agua dulce; diferenciación poblacional; diversidad genética; freshwater biodiversity; genetic diversity; genética poblacional; population differentiation; population genetics