Toxicity of nickel to aquatic organisms is known to be affected by factors such as dissolved organic carbon (DOC) concentration and water hardness. Bioavailability models have been developed more than a decade ago that have been validated for European surface waters. Australian surface waters, however, are quite different in composition. This collaborative research with Australian, UK, and USA researchers resulted in slightly modified bioavailability models for a range of indigenous organisms that are shown to predict nickel toxicity in local waters relatively accurately. These models can be used in Australian water quality guideline derivations.

It is generally assumed that as long as the majority of species experiences no direct adverse effects due to a single substance (i.e. Potentially Affected Fraction, PAF < 5%), no significant structural or functional effects at community‐level are expected to occur. Whether this assumption holds for mixed metal contamination is not known. Here, we tested this by performing a microcosm experiment in which a naturally occurring freshwater planktonic community was exposed to a Cu‐Ni‐Zn mixture for 8 weeks, and in which various structural and functional community‐level traits were assessed.

Our freshwater ecosystems are severely threatened by many factors including pollution and climate change. In the current synthesis, we focus on the potential role of epigenetics (molecular modifications of DNA that do not change the DNA sequence). We highlight examples of the roles of DNA methylation and histone modifications, well-known epigenetic mechanisms, in the response to climate change. We conclude by pinpointing the most promising avenues for future research directions to improve our understanding on how freshwater organisms cope with climate change. With this synthesis, we provide a thorough summary of the field and put forward key research questions that need to be addressed.