Leg3 Cape Town to Melbourne and the Southern Ocean

The first preliminary results were presented by Dr. Toste Tanhuas Talk on the Ocean Summit in Cape Town got some audience, which listened.

The system itself was full functional with minor maintenance needed. Some minor things as a loose screw and precautionary exchange of a small pump after more than roughly 9150 nautical miles were the hardest parts to “fix” the system for the next Leg to Melbourne in the Southern Ocean.


Maintenance of the scientific unit (OceanPack™ RACE by SubCtech and MP Filtersystem by bbe Moldaenke). ©Sören Gutekunst

Really exciting were our collected datasets. After some reprogramming for automatization we got our results of Leg 1 and Leg 2.

Uncalibrated preliminary results of the pCO2 data. ©Sören Gutekunst

Here we can see the spots where our ocean has a higher value of carbon dioxide than the air we pollute. At the moment our carbon dioxide content is roughly at 405 ppm in the air. This means for values above this concentration the Ocean releases carbon dioxide for example due to upwelling of CO2 rich Deepwater and degassing. Lower concentrations lead to absorption of CO2.


Off-shore in Cape Town. ©Sören Gutekunst

Some more science behind CO2: A high amount of carbon dioxide leads to carboxic acid, which we know from our daily lives in sparkling water. Therefore, a huge amount of CO2 is pushed into the water-bottle when it’s produced. Once we open the bottle the unstable high carboxic acid concentration lead to a degassing as carbon dioxide.
Besides, the higher the amount of CO2 in water – the more carboxic acid is dissolved – the lower is the pH of the water.

This means an increasing CO2 in the air lead to a more acidic habitat in our Oceans. It is called “Ocean acidification” and makes the Oceans more and more unfavourable for marine organisms such as crusteans, corals and even some fish species.



More informations:
GEOMAR: Round the World Regatta: Science wins
AtlantOS Horizon2020: first results from ocean observation during volvo ocean race
Sky News: analysis shows there could be more plastic in sea than first feared
Sky Ocean rescue: not just a tough race volvo ocean races ground breaking research campaign
VOR: Millions of micro plasticparticles found in European waters
VOR: Ocean Summit Cape Town