[1] Vilnius State Univ, Inst Ecol, LT-08412 Vilnius, Lithuania
[2] Finnish Inst Marine Res, FI-00561 Helsinki, Finland
[3] Alfred Wegener Inst Polar & Marine Res, D-27570 Bremerhaven, Germany
[4] Finnish Game & Fisheries Res Inst, FI-00791 Helsinki, Finland
[5] Bundesforsch Anstalt Fis, Inst Fischerokol, D-27472 Cuxhaven, Germany
[6] Inst Oceanol, PL-81712 Sopot, Poland
[7] Vilnius State Univ, Dept Bot & Genet, LT-03101 Vilnius, Lithuania