Controlled Experiments in the SeaSim
SeaSim ocean acidification experiment conducted by Kristen Anderson and Neal Cantin. Photo: Brecht Vanoverbeke.
Controlled CO2 enrichment experiments in the National Sea Simulator (SeaSim)
Researchers at AIMS are undertaking controlled aquarium experiments in the new National Sea Simulator (SeaSim) in Townsville, Queensland, to better understand the effects of ocean acidification on all life stages of marine organisms. They are also investigating the joint effects of ocean acidification and other pressures like warming and reduced water quality.
"In our ‘cradle to grave' experiment we are testing how corals and sponges from different life stages – from babies right through to adults - respond to the cumulative pressures associated with climate change" explained AIMS research scientist, Dr Nicole Webster
“We are also investigating what mechanisms reef invertebrates may use to acclimate or adapt to ocean acidification. Initial observations from the CO2 seeps have revealed that shifts in microbial symbiont populations may contribute to the sensitivity or tolerance of different species to ocean acidification and these findings are now being validated in experimental mesocosm systems.”
SeaSim control system used to manipulate carbonate chemistry in experimental tanks. Photo: Craig Humphrey, AIMS.
In a new SeaSim study using large mesocosms (these are large tanks that house not just one target organism, but whole assemblages of species), the effects of ocean acidification and warming, and the potential of adaptation will be examined over multiple generations.
Experiments have started to confirm some of the observations made at the CO2 seeps.
For example, experiments conducted by Dr. Neal Cantin and collaborators have shown that corals contrast in their sensitivity to temperature and ocean acidification, with some species being very robust to CO2 enriched ocean acidification, yet sensitive to thermal stress. The potential benefits from CO2 enrichment have also been documented for tropical seagrass species, but only in areas of high light and good water quality.
Researchers are now trying to learn what the underlying mechanisms are that determine the CO2 tolerance in the hardiest species.