Auswirkungen kombinierter Klimawandelstressoren auf die Nachkommen von Korallenrifffischen
Biochemie und Physiologie der Tiere
Zusammenfassung der Projektergebnisse
Climate change poses a fundamental threat to the well-being of terrestrial and aquatic species, with potentially adverse consequences on individual- and population-level scales. The world’s oceans have been predicted to shift with climate change, and simulations with different greenhouse gas emission scenarios have predicted severe ocean warming, acidification, and deoxygenation for mid- and end-of-century conditions (2050 and 2100, respectively). Experimental approaches simulating these scenarios have suggested sensitivities of marine life to any of these stressors in isolation, but we can only surmise the combination. Therefore, understanding how the individual health and fitness of marine species, such as fishes, will be affected by combined climate change stressors is of paramount importance. Tropical fish species may be particularly sensitive to changes in their environment, as they live already close to their upper performance limits. In fact, early life stages of tropical fishes may be most vulnerable due to developmental constraints (e.g., not fully-developed organs and performance). At the same time, larvae connect the patchily distributed coral reef habitats of adult fishes through pelagic drift and are therefore fundamental for dispersal and population connectivity. In this project, a multidisciplinary approach was taken to test whether combined climate change stressors negatively impact health and fitness of tropical fish larvae. First, setups for rearing and exercising early life stages of fishes were built and tested. Second, experimental trials were conducted during which fish larvae were exposed to combined ocean warming and acidification at levels predicted for 2050 and 2100. Fishes were tested throughout early development to analyze growth, condition, and their maximum swimming performance. Furthermore, the initially planned gill histology and metabolic enzyme analyses were replaced with more advanced molecular techniques, and samples taken for transcriptomics and metabolomics. In a third step, physiological data on swimming performance were integrated into an individual-based, biophysical model, to better predict dispersal and connectivity of tropical fishes under climate change conditions. Due to a delay in the experimental phase, the data analysis is still ongoing. The results are expected to help disentangle the underlying causes of combined climate change stressors on early life stages of tropical fishes, and the potential effects on their population dynamics (dispersal and connectivity) on the Great Barrier Reef (Australia). Linking molecular, physiological, behavioural, and ecological modelling approaches has created a strong momentum to holistically investigate the cause-and-effect mechanisms of combined climate change effects on larval fishes, and outlined promising opportunities for follow-up research.
Projektbezogene Publikationen (Auswahl)
-
“Swimming performance of marine fish larvae: review of a universal trait under ecological and environmental pressure”, Reviews in Fish Biology and Fisheries, 2020
Downie, A.T., Illing, B., Faria, A.M. and J.L. Rummer
