Data collected within various monitoring programmes. Analyzed according to HELCOM MONAS guidelines. Abundance on species level.

Data collected within various monitoring programmes and surveys. Standard quantitative phytoplankton techniques following HELCOM MONAS guidelines. Counts and sometimes biovolumes on species level.

Data contain abundance (number of individuals per species) and biomass (wet weight or dry weight per species) information.

Data collected within various monitoring programmes and surveys. Standard zoobenthos techniques using benthic grabbers and species analyses for counts and weights on species level.

Epibenthos has been nationally monitored in Sweden since 1992. The monitoring program was initiated by the Swedish Environmental Protection Agency and later the Swedish Agency for Marine and Water Management took over the responsibility and financing of the program. The monitoring is performed by Stockholm University, University of Gothenburg and Linnaeus University. The data is stored in the database SHARK, hosted and maintained by the Swedish Meteorological and Hydrological Institute. The epibenthos monitoring program studies hard and soft bottoms from the surface down to 10-20 meters. Data is collected in transects or squares with help of divers. Species abundances are determined directly by the divers or photographs are taken and analyzed later. More information is available in Swedish at https://www.havochvatten.se/hav/samordning--fakta/miljoovervakning/miljoovervakningens-programomrade-kust-och-hav/delprogram-vegetationskladda-bottnar.html

The KPLANK database includes data on phytoplankton, covering the Finnish coastal areas as well as the offshore areas of the Baltic Sea. The quantitative data mainly stem from the Finnish national monitoring program and statutory monitoring programs. In total the database contain approximately 240 000 quantitative records including size classes. The data span from 1937 to present. The database is regularly maintained and data is added continuously.

The dataset include Finnish zooplankton monitoring data from the Baltic Sea. The Finnish zooplankton monitoring program started in 1979 and is still ongoing. The sampling has normally taken place in late summer (August), but since 2014 sampling is also carried out in early summer (May-June).The zooplankton monitoring was performed by Finnish Institute of Marine Research until 2008, thereafter the Finnish Environment Institute is responsible for the monitoring program. Samples are taken using a WP-2 net (normally 2550 cm2 opening and 100 um mesh size). The monitoring follows the HELCOM COMBINE guidelines, but subsampling is done using Folsom splitter. The dataset is also accessible through the NOAA COPEPOD database.

The POHJE database includes data on benthic macrofauna, covering the Finnish coastal areas as well as the offshore areas of the Baltic Sea. The quantitative data mainly stem from the Finnish national monitoring program and statutory monitoring programs, but also data from surveys and research projects are included. In total the database contain aproximately 100 000 quantitative records including developmental stages, with a time span from 1965 to present. The database is regularly maintained and data is added continuously.

Zooplankton data from Polish Exclusive Economic Zone of the Baltic Sea collected in frame of the Polish Monitoring Programme. Data include information on species composition, abundance and biomass of zooplankton community for the period of 2002-2012.

Phytoplankton data from Polish Exclusive Economic Zone of the Baltic Sea collected in frame of the Polish Monitoring Programme. Data include information on species composition, abundance and biomass (biovolume and C biomass) of phytoplankton community for the period of 2002-2012.