Before our second visit to the MBRS we encountered some local fishermen, who told us of crabs they’d caught with pitted and damaged carapaces. Hmmmmm, we thought. A potential symptom of acidification! But how could the crabs have been exposed to low pH waters like those predicted to occur 50 to 100 years into the future?
A day of detective work followed at the site of one of Straddie’s mysterious forest springs, which injects acid spring water onto the local seagrass meadows. Some water chemistry analyses and clever calculations by our GS students indicated that this site could be the source of the acidified seawater. And so we had discovered a wonderful field site – a natural simulation of our future oceans.
Of course, this meant that there was no need to deploy our portable Free Ocean Carbon Enrichment system to inject carbon dioxide into local waters. Instead, we spent time in the mangrove forest, tracing the path of the acidified water out to the shore and designing our new experiments.
Our goal was to first determine if the seagrasses growing near the spring were altered. We started by testing their value as food for local grazers….starting with the rabbitfish, an important seagrass herbivore also know as the “happy moment” fish. (It’s a cute fish, but like everything else here, it is venomous.)