The mescosom facility at the Wadden Sea station of the Alfred Wegener Institute on the island of Sylt provides a novel platform to study the effects of multiple stress scenarios at the intertidal community level. In 2022, a mesocosm experiment was conducted over a three-month period to study the effects of nearshore warming on the carbon cycle by quantifying growth and respiration rates of a mussel bank community. In the context of that larger study we compared abiotic factors as well as growth and condition of blue mussels (<em>Mytilus edulis</em>from) the mesocosms and from the Wadden Sea to test the functionality of the facility. Temperature treatments (ambient, +1.5°C and +3°C) accurately followed the calculations made by the software. Water temperature, salinity and pH in the mesocosms showed good agreement with field data. There were no significant differences in growth and condition between mussels from mesocosms and those in the field. Proper functioning of the mesocosm facility is a prerequisite for reliable data acquisition from further experiments. The similarity of abiotic and biotic  factors between the mesocosms and the field demonstrating the great potential of the facility for experiments under near natural conditions. The density of filter-feeder, however, should be adjusted based on the species due to the lower plankton concentrations in the mesocosms compared to the concentration in the field.

Primary Presenter: Knut Mehler, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (knut.mehler@awi.de)

Authors:

Anna Steinmann, University of Kiel  (anna.steinmann@awi.de)

Johannes Rick, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research  (jrick@awi.de)

Lea Joly, GEOMAR  (ljoly@geomar.de)

Maysa Ito, GEOMAR  (mito@geomar.de)

Marco Scotti,   (mscotti@geomar.de)