Bridging the gap between field and lab: Applicability and performance of the Sylt mesocosms facility to simulate climate change scenarios on intertidal benthic communities

Climate change significantly threatens coastal ecosystems, making effective conservation strategies essential and reliant on accurate data. This study employed the Sylt mesocosms facility to examine how coastal marine communities respond to both individual and combined stressors. Within the broader context of this research, environmental variables such as pH, temperature, and nutrient levels in the mesocosms were continuously monitored and compared with field data. In addition, growth rates of blue mussels (Mytilus edulis) and Pacific oysters (Magallana gigas) were assessed, along with the body condition of M. edulis, to evaluate the functionality of the facility. While the water temperature in the mesocosms remained closely regulated according to the programmed set points, the pH and nutrient levels varied in a manner similar to natural field conditions. The concentration of chlorophyll a, used as an indicator of food availability within the tanks, was lower than in the field but did not significantly influence the growth rates and conditions of the filter feeders. The facility demonstrated its effectiveness throughout the experimental period in controlling temperature, highlighting its potential for future research on the effects of single and multiple stressors in near-natural conditions. These findings highlight the importance of mesocosms as a research tool for understanding the complex dynamics of marine ecosystems facing climate change.