Impacts of alien invasive species on large wetlands

Abstract

Biodiverse and productive, tropical wetlands sustain large human populations globally. However, the extent of their use makes them vulnerable to introductions of nonnative species. Whether intentional or accidental these introduced species have the potential to become invasive and cause significant biotic change through mechanisms including competition, predation, hybridization, disease transmission, and ecosystem engineering. The societal impacts of invasive species can be similarly extensive, including loss of amenity, income and damage to health. Tropical wetland invaders take many forms, and some of the most damaging include plants: water hyacinth Eichhornia crassipes, giant salvinia Salvinia molesta, and melaleuca tree Melaleuca quinquenervia; invertebrates: golden apple snail Pomacea canaliculata, red swamp crayfish Procambarus clarkii and Australian redclaw crayfish Cherax quadricarinatus; and vertebrates: Nile tilapia Oreochromis niloticus, cane toad Rhinella marina, and Burmese python Python bivittatus. These examples exhibit a wide range of impacts and warrant diverse management options to control them, with varying outcomes. In large wetland systems, biological invasions often interact alongside a number of other anthropogenic impacts. Using three wetland case studies—the Greater Everglades Ecosystem (GEE) in North America, Kafue Flats in Africa, and the Lower Mekong Basin (LMB) in Asia—we illustrate the cost and complexity of invasion biology and management at this scale. © 2022 Elsevier Inc. All rights reserved.