An international team of researchers including the GEOMAR Helmholtz Centre for Ocean Research Kiel has produced the first global estimate of mercury emissions from hydrothermal sources at mid-ocean ridges based on measurements. The researchers were able to show that most of the mercury in the ocean comes from human activities - and can therefore be reduced. Their findings have been published in the journal Nature Geoscience.
Ten years ago, the United Nations agreed to minimise mercury pollution in the environment to protect human health: the Minamata Convention was adopted in Geneva in 2013. Signatory countries committed to controlling and minimising the release of mercury. One of the main sources of human mercury intake is the consumption of contaminated fish, which accumulate mercury dissolved in seawater. It is estimated that anthropogenic activities have increased the global mercury reservoir in the ocean by 21 per cent. However, this figure is difficult to verify because it was not known exactly how much natural mercury was present in the ocean before anthropogenic emissions began. It is therefore equally difficult to say how much these have influenced mercury levels in fish.
To fill this knowledge gap, an international team of researchers led by the French National Centre for Scientific Research (Centre national de la recherche scientifique, CNRS) has now produced the first global estimate of mercury emissions from hydrothermal sources at mid-ocean ridges, volcanically active areas in the world's oceans, based on measurements.
Read more at: Helmholtz Centre for Ocean Research Kiel (GEOMAR)
ROV KIEL 6000 working on the seabed in the area of the Mid-Atlantic Ridge: rock analyses were also included in the new study. (Photo Credit: ROV team, GEOMAR)