It seems like coral scientists and researchers are constantly finding new ways that corals are dying and how coral reefs are an endangered ecosystem, but for once, it seems like at least one group of corals will be able to weather the coming climatic storm. New research on the Caribbean photosynthetic gorgonian Eunicea fusca indicates that this is one species of reef coral which can pretty much grow and thrive under a wide range of pH concentrations.
To test the effect of ocean acidification on gorgonian growth, over a four week period samples of Eunicea fusca gorgonians were subjected to a range of pH levels ranging from 8.1 all the way down to 7.1 – pH is a logarithmic scale so a pH level of 7.1 is ten times more acidic than 8.1. Under all of these conditions the samples of the E. fusca gorgonians managed to grow and calcify although there was a noticeable decline in growth at the lower ranges of pH.
All corals can manipulate their internal chemistry to raise internal pH levels to the point where aragonite crystals will form, this is precisely how corals calcify calcium carbonate into the skeletons they need for support. However while stony corals, scleractinians, need a relatively high environmental pH level to calcify, it seems gorgonians are better at growing when seawater is on the relatively acidic side. This means that while stony corals will suffer and struggle under the effects of ocean acidification in the coming decades, gorgonian species are likely to be much less affected so the diversity and abundance of gorgonians is likely to remain fairly healthy in the face of global climate change. [Springer Link]