Patrick McSweeney

1 Introduction Freshwater ecosystems host approximately 50% of all described fish species, whilst only accounting for 0.01% of the habitable water on earth (Dudgeon et al. 2006; Tedesco et al. 2017). Freshwater fish are facing rates of decline exceeding those of their saltwater counterparts and terrestrial species (Sala et al. 2000; Duncan and Lockwood 2001; Green et al. 2015).