1. a Institute of Ecology of Vilnius University , Akademijos 2, LT-08412 , Vilnius-21 , Lithuania
2. b Department of Botany and Genetics , Vilnius University , Čiurlionio 21, LT-03101 , Vilnius , Lithuania
3. c Alfred Wegener Institute for Polar and Marine Research , Am Handelsshafen 12, 27570 , Bremerhaven , Germany
4. d Göteborg University , Box 463, SE 405 30 , Göteborg , Sweden
5. e Institute of Applied Ecology , Alte Dorfstrasse 11, D-18184 , Broderstorf , Germany
6. f Institute of Oceanology , P.O. Box 197, Sopot , Poland
7. g Institute of Applied Environmental Research , Stockholm University , SE-106 91 , Stockholm , Sweden