title: Salinized rivers: degraded systems or new habitats for salt-tolerant faunas?
abstract: Anthropogenic salinization of rivers is an emerging issue of global concern, with significant adverse effects on biodiversity and ecosystem functioning. Impacts of freshwater salinization on biota are strongly mediated by evolutionary history, as this is a major factor determining species physiological salinity tolerance. Freshwater insects dominate most flowing waters, and the common lotic insect orders Ephemeroptera (mayflies), Plecoptera (stoneflies) and Trichoptera (caddisflies) are particularly salt-sensitive. Tolerances of existing taxa, rapid adaption, colonization by novel taxa (from naturally saline environments) and interactions between species will be key drivers of assemblages in saline lotic systems. Here we outline a conceptual framework predicting how communities may change in salinizing rivers. We envision that a relatively small number of taxa will be saline-tolerant and able to colonize salinized rivers (e.g. most naturally saline habitats are lentic; thus potential colonizers would need to adapt to lotic environments), leading to depauperate communities in these environments.
authors.affiliation: Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory 2601, Australia ben.kefford@canberra.edu.au.
authors.forename: Ben J
authors.identifier: http://orcid.org/0000-0001-6789-4254
authors.initials: BJ
authors.lastname: Kefford
authors.affiliation: Environmental and Molecular Toxicology Program, Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA.
authors.forename: David
authors.initials: D
authors.lastname: Buchwalter
authors.affiliation: BETA Technology Centre, Aquatic Ecology Group, University of Vic-Central University of Catalonia, Spain Freshwater Ecology and Management (F.E.M.) Research Group, Universitat de Barcelona, Barcelona 08028, Spain.
authors.forename: Miguel
authors.identifier: http://orcid.org/0000-0003-3864-7451
authors.initials: M
authors.lastname: Cañedo-Argüelles
authors.affiliation: Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory 2601, Australia.
authors.forename: Jenny
authors.initials: J
authors.lastname: Davis
authors.affiliation: Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory 2601, Australia.
authors.forename: Richard P
authors.identifier: http://orcid.org/0000-0003-2295-449X
authors.initials: RP
authors.lastname: Duncan
authors.affiliation: School of BioSciences, Bio21 Institute, The University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Ary
authors.identifier: http://orcid.org/0000-0001-9497-7645
authors.initials: A
authors.lastname: Hoffmann
authors.affiliation: Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory 2601, Australia.
authors.forename: Ross
authors.identifier: http://orcid.org/0000-0002-5287-2455
authors.initials: R
authors.lastname: Thompson
mesh_terms: D000818:Animals; D044822:Biodiversity; D017753:Ecosystem; D007313:Insecta / Q000502:physiology*; D045483:Rivers / Q000737:chemistry*; D054712:Salinity
keywords: adaptation; freshwater; major ions; novel ecosystems; osmoregulation; salinity