Yes ! It is almost that day that we fly to Hawai’i. We, that is Dr. Phil Renforth from Cardiff University and myself, Dr. Francesc Montserrat of the Netherlands Institute for Sea Research. Why is it interesting for you to read about two researchers going to the Big Island of that famous archipelago in the central Pacific Ocean, you ask ? Obviously, we are not going there to sunbathe…no, we are going there to do a three-week field research on a natural olivine beach. Papakolea Beach on the southern tip of Big Island is a beach that consists mainly of olivine grains. We are very much interested in the incredible capacity of this green mineral to capture CO2 from both atmosphere and seawater and potentially counteract climate change effects, such as ocean acidification. Before ever coming close to trying this out in real life we wanted to investigate how this works in a natural setting, where olivine has been weathering for hundreds, no thousands of years. We are going to Papakolea Beach to try and measure the effect this dissolving mineral has on both the chemistry of the ocean and the state of the surrounding ecosystem. Please keep following this blog for the coming weeks, as we will try and update it regularly.
As it was predicted in various models and observed in many laboratory tests, so it has been demonstrated in the real world. Mimicking the increase in acidity of the world’s oceans in response to the ever increasing CO2 in the atmosphere, marine scientists from Australia and the US have performed a field experiment in circular reefs along the Great Barrier Reef, in which they increased the pH of the seawater to pre-industrial levels. As a result, the corals in those “pre-industrial” reefs were reported to grow some 7% faster than in seawater with a pH that is normal nowadays.
Mussels can adapt to their acidifying ocean by changing the composition of their hard parts. In an ever more corrosive environment, mussels changed the mineralogical makeup of their calcareous shells. Shells normally consist of calcium carbonate which is ordered in a crystalline fashion, with strong and resistant properties. However, under ocean acidification conditions, with a lower pH, the calcium carbonate of these experimental mussel shells consisted of much more amorphous calcium carbonate, leaving the shells more vulnerable to predation by crabs and seagulls and the crushing forces of waves. This is a very strong example of secondary effects of ocean acidification, where organisms suffer from the consequences of climate change in an almost cryptic way. The danger sits in the fact that these changes on an organism level might go by unnoticed, until it is too late.