Exploring the interplay of biotic interactions and salinity stress in freshwater invertebrate assemblages: reply to Chessman (2022)

Abstract

The most parsimonious interpretation of our experimental findings (Bray 2019; Kefford 2022) is that the effect of experimental increases in salinity on stream macroinvertebrate communities, was altered by organisms from a high-salinity site. This interpretation is consistent with long-established and widely accepted ecological and ecotoxicological theory. The suggestion (Chessman 2022) that the initial community was confounded, that it converged within the first week of the experiment and then diverged again, is neither parsimonious nor explicable by theory. All experiments are imperfect, yet we maintain that our experiment is informative, and we encourage other researchers to generate new data to inform on the degree to which abiotic and biotic effects of salinity, and other abiotic stressors, affect ecological communities.