Fig. 1: The sequential incubation experiment was performed along a salinity gradient, ranging from freshwater to coastal seawater conditions.

A Map of the four incubation sites (Bremen, Brake, Bremerhaven, Helgoland) spanning the Weser River to the offshore island of Helgoland (North Sea) in Germany. Two cages were set up; the first (Transferred Cage) was sequentially incubated along the salinity gradient while the second (Stationary Cage) remained in the offshore site throughout the entire duration of the experiment, acting as a marine control. B Daily conductivity and temperature at each site throughout each respective incubation period. Vertical dashed lines are indicative of sampling dates. Source: Senator für Umwelt, Bau und Verkehr (Bremen); Niedersächsischer Landesbetrieb für Wasserwirtschaft, Küsten- und Naturschutz, NLWKN (Brake); Wasserstraßen- und Schifffahrtsamt Bremerhaven (Bremerhaven); Biologische Anstalt Helgoland, Alfred-Wegener-Institut (Helgoland).