Image of the Month: May 2021
Barnacles and sea lettuce on rocks of the Swedish west coast in the Skagerrak
What is special about the Kiel Fjord is that the oxygen content, pH value and temperatures can fluctuate greatly within weeks or even days. Are organisms that live here better prepared for climate change than others? Marine scientists from Kiel addressed this question. For their studies, they exposed barnacles to different CO2 concentrations. The researchers compared barnacles from the Kiel Fjord with a population from the chemically more stable archipelago off the west coast of Sweden. The organisms from the fjord, which have to cope with fluctuating CO2 concentrations anyway, reacted quite insensitively to the future scenarios. The barnacles' shells suffered somewhat at very high concentrations, but these were purely external characteristics; reproduction and mortality rates showed no changes. On the other hand, the stress tolerance of the Swedish barnacles, proved to be relatively low; in the experiments they no longer grew to the same extent as usual and more individuals died. Precisely because they do not live under such varying environmental conditions, they are probably much more susceptible to change.
Photo: Christian Pansch
