In an outdoor mesocosm study, we investigated the differential effects of three simulated upwelling events coupled with ocean warming (1 to 5 °C above ambient) on a temperate benthic community in the Western Baltic Sea.

Experimental system: Kiel Outdoor Benthoscosms (see https://www.aquacosm.eu/mesocosm/kob-kiel-outdoor-benthocosms/ and http://dx.doi.org/10.1002/lom3.10055)Experimental duration: 2.5.2018 through 11.09.2018Experimental communities: Addition (at natural relative biomasses) of the macroalgae Fucus vesiculosus, Fucus serratus and Agarophyton vermiculophyllum, as well as the mesograzer species Idotea sp., Gammarus sp. and Littorina littorea. Further species recruited by the contiunous flow-through of non-filtered fjord waterSimulated warming: Tanks maintained (by computer controlled heaters and chillers) at temperature increments of 0, 1, 2, 3, 4, and 5°C above the naturally fluctuation fjord SSTSimulated upwelling events: UPW1=3.7.2018 - 9.7.2018, UPW2=4.8.2018 - 11.8.2018, UPW3=28.8.2018 - 3.9.2018ow= ocean warming (i.e. warming elevels above ambient), upw = presence or absence of a simulated upwelling treatment