Severely Understudied Impacts of Fishes in North America’s Arid Land Aquatic Ecosystems

Authors: Eric Moody, Ellen Albright, Katie Cope, Rachel Fleck, Haley Grigel

Year: 2018

Abstract

Fishes serve as keystone species in many freshwater ecosystems by modifying habitat, altering nutrient cycling, and imposing top-down effects on food webs. As a result, the important role of threatened fishes in ecosystems is often cited as a reason why they should be protected. However, it is unclear to what extent the role of many threatened fishes in ecosystem dynamics is understood. We conducted a literature review of studies of the ecosystem impacts of fishes in North America to examine whether certain species and/or regions are understudied. We found that threatened species were frequently studied at higher latitudes, but that the ecosystem role of fishes was poorly studied regardless of imperilment at lower latitudes. Taxonomically, salmonids were exceptionally overstudied relative to the number of species in North America, while many families that predominate in arid and semiarid regions were understudied (e.g., Cyprinidae, Poeciliidae, and Cichlidae) or completely unstudied (e.g., Cyprinodontidae, Goodeidae, and Atherinopsidae). We then developed an index describing the relative degree of imperilment and our understanding of the ecosystem role of the fish fauna for the freshwater ecoregions of North America. According to this index, most desert ecoregions and those of the central Mexican plateau are severely understudied despite their highly imperiled fish fauna. Future work on the ecosystem-scale importance of these threatened species will provide more concrete support for campaigns to protect them from extinction and improve management of these waterbodies.