Freshwater species on the move: mechanisms and consequences

Dr Wilco Verberk

Radboud University Nijmegen

Changing climate has been identified as one of the most important persistent threat to freshwater biodiversity. Here I will highlight recent ecophysiological studies on the mechanisms and consequences of climate change for freshwater species. In terms of variability in environmental temperatures, freshwaters occupy an intermediate position relative to marine and terrestrial realms. In addition to thermal variability, oxygen conditions are also variable. Several studies have shown such oxygen fluctuations to be important in governing thermal responses of freshwater taxa, highlighting interactions between multiple stressors such as hypoxia and warming. Consequently, an oxygen perspective can improve our understanding of the impacts of warming. For instance, vulnerability of freshwater taxa to climate change will likely depend on their mode of breathing (air breathers vs water breathers). Habitat use will also matter. For instance, running waters tend to be less variable in terms of oxygen and temperature compared to standing waters. Similarly, large scale patterns in biodiversity have highlighted differences in dispersal ability between taxa from running waters (poor dispersers) and those from standing waters (good dispersers). This means that the global redistribution of freshwater animals will be biased depending on breathing mode, habitat use, and dispersal ability.

Biography:

Wilco Verberk is an Assistant professor at the Department of Animal Ecology and Physiology, Radboud University Nijmegen, the Netherlands. He received his Ph.D. in Freshwater Ecology in 2008, investigating species responses to ecosystem restoration. His studies now focus on the ecophysiology of aquatic invertebrates to better understand their thermal niche and predict their responses to climate change.