Baltic Marine Environment
Protection Commission


Baltic Marine Environment
Protection Commission


Quality Assurance of Phytoplankton Monitoring in the Baltic Sea (PEG QA)



The main target of the project is to ensure and maintain high quality standard of the international Baltic Sea regional phytoplankton monitoring within the HELCOM COMBINE Programme. This should be achieved by:

  • Maintaining annual training courses (workshop)
  • Maintaining the phytoplankton biovolume list
  • Participation in intercalibrations
  • Maintaining the HELCOM Monitoring guidelines for Phytoplankton – Species composition, abundance and biomass
  • HELCOM PEG will serve as a forum for:
  • discussion of phytoplankton indicators being developed in HELCOM and the results of the indicator evaluation of future HELCOM holistic assessments
  • The main activities within the project will be carried out at the annual workshops


Quality assurance of data is an important component of the HELCOM monitoring programme, and measures were early taken to evaluate and improve the recommended methods through intercalibrations between the different partners. In 1991 HELCOM PEG was established, with the main aim to unify methods of collection, counting and identification of phytoplankton species. Since accurate biomass estimates are important in phytoplankton monitoring, PEG has also made considerable efforts to standardise size-classes and biovolumes of phytoplankton species found in the Baltic Sea. The use of a standardised species list with fixed size-classes and biovolumes is a decisive measure to improve the quality of the phytoplankton counting method and the comparability of results.


The main activities within the project will be carried out at the annual workshops. Intersessional activities will be organized if needed. The following types of activities are planned:

Training coursesTo maintain continuity and high quality in phytoplankton identification and quantification, in particular because a new generation of phytoplankton researchers and analysts are currently joining the PEG;
To follow recent changes in the taxonomy of Baltic Sea relevant phytoplankton in order to keep the PEG Phytoplankton species/biovolume list up to date.
The training courses
are planned to encompass:
a)       Identification of phytoplankton species;
b)      Maintaining and enhancing the competence of analysts to identify alien species;
c)       Enhancing the competence of analysts to distinguish resting stages from vegetative stages in the plankton
Presenting representative and validated images of Baltic Sea phytoplankton species, publicly available in the HELCOM PEG image gallery at
IntercalibrationsTo keep the high standard of phytoplankton monitoring in the Baltic Sea, to assure the comparability of results. The group is active in selecting suitable intercalibrations which could be participated by the group members. At the annual meetings, we allocate time to discuss and find solutions for the possible quality problems revealed within intercalibrations. In addition, organizers of the intercalibrations are invited to the meeting for presentation of the results where the results will be evaluated and discussed and can lead to future suggestions for intercalibrations
Further unifying the counting method To continuously update the HELCOM monitoring manual for phytoplankton species composition, abundance and biomass.
Updating the biovolume fileTo add new taxa and size classes when necessary; to update the biovolume file according to recent taxonomical changes in co-operation with ICES Data Centre.
Harmonization of biovolume calculations between CEN standard EN16695:2015 and the PEG biovolume list To start the harmonization of biovolume calculations between the PEG biovolume file and the CEN standard EN-16695:2015 by starting with taxa that show major differences.

At the training courses it is planned to consider:

  1. Identification of phytoplankton species;
  2. Maintaining and upgrading of the expertise for identification of alien species;
  3. Making representative and validated images of the Baltic Sea phytoplankton species public in the HELCOM PEG image gallery at,

Intercalibrations and further unifying the counting method includes:

Interlaboratory intercalibration and checking the general methodology, species identification, counting strategy, biovolume estimation etc.

The venue of the workshops will be circulated between the Contracting Parties and their marine laboratories. Suggested host countries are: Poland in 2020, Sweden (Umeå University) in 2021 and in 2022 Denmark. Intersessional activities will be organized if needed.

The project period is five years. Ms. Iveta Jurgensone, Latvia, will be the chair and convener during 2020-2024.

Expected outcomes

The outcome of the project will be:

  1. Annual reports from the three workshops to HELCOM State & Conservation;
  2. Annually revised species/biovolume list of Baltic Sea phytoplankton species;
  3. Updated HELCOM Monitoring manual for Phytoplankton – Species composition, abundance and biomass
  4. We will discuss the existing and possible new phytoplankton indicators and the outcome of this will be presented as a part in the annual workshop report.
  5. After participating intercalibrations, the outcome of results and discussions will be presented as a part in the annual workshop report.
  6. Updated HELCOM environmental fact sheet (Cyanobacteria biomass);
  7. Continuation of contribution of quality-checked images to the HELCOM PEG image gallery at;
  8. Final report (2020-2024).

Consistency with HELCOM priorities

In this project the HELCOM priorities are met by assuring that the quality of the phytoplankton data is high enough to evaluate effects of eutrophication, changes in biodiversity and long-term trends. This data is for example crucial for the work with the EU Water Frame Directive.


The project will be carried out in 2020-2024 as a continuation to the ongoing HELCOM PEG project for 2017-2019. More specific timetable:

Regular tasks will be discussed during all workshops, for example:

  • discussion on new species and size classes that have occurred in the previous year’s samples including non-indigenous species. New species have to be presented with picture showing characteristic features for the species and location of sampling
  • discussion of new environmental fact sheets and updating of the existing one (Cyanobacteria biomass)
  • harmonization of species identification by common microscopy of samples from the Baltic Sea
  • harmonization of analyzing methods by discussing the methodology and intercalibration results to assess homogeneity in the analyses
  • information on recent changes in taxonomy of planktonic microalgae
  • new images to add to the phytoplankton image gallery
  • information on new relevant literature, projects about e.g. the development of phytoplankton indicators, meetings and conferences
  • review of phytoplankton indicators being developed by Lead Countries.

Specific tasks for the workshops are:

Workshop 2022, to be held in Poland

  1. Phytoplankton identification workshop: Summaries on the Advanced Phytoplankton Course APC12 by Iveta Jurgensone and Heidi Hällfors
  2. Practical work with participants’ samples.
  3. Discussion of the next intercalibration which will be recommended to be participated by the group members. Wishes of the group will be sent to the representatives of the ProfTest SYKE, which is organizing interlaboratory proficiency tests for phytoplankton.
  4. Discussion about which indicators contracting parties used in their latest MSFD assessment (to exchange experiences from the procedure used in different countries and how the different indicators works in different sea areas), which indicators should be prioritized according to the outcome of HELCOM indicator workshops and later progress in the HELCOM BLUES project.

Workshop 2023, to be held in Sweden

  1. A training course on Baltic Sea phytoplankton identification, Heidi Hällfors, Finland.
  2. A lecture about choanoflagellates, teacher will be decided
  3. Planning the next project (2025-2027).
  4. Discussion of the HOLAS 3 assessment of pelagic habitats

Workshop 2024, to be held in Denmark

  1. A training course diatoms, Nina Lundholm, Denmark or on diatom resting spores and dinoflagellate cysts, Anna Godhe, Sweden.
  2. Presentation of the results from the Proftest SYKE 2023 intercalibration and discussion of the outcome.
  3. Discussion of assessment of pelagic habitat to be included in HOLAS IV.

Specific tasks to support the development and evaluation of phytoplankton indicators:

As this project period is in the middle of the 6 years cycle, focus will be on discussions on revised indicators or new proposed indicators that have been developed after the current assessment period.

Useful links to the products of HELCOM PEG

Biovolume file, with biovolumes and fixed size-classes used for the calculation of phytoplankton biomass in routine monitoring of Baltic Sea phytoplankton (updated 2013). For geometrical shapes used, see Olenina et al 2006. Note that the above Excel-file of biovolumes should be used both for species and biovolume list in routine monitoring of Baltic Sea phytoplankton.

Phytoplankton sampling and analysis is carried out according to the Phytoplankton monitoring manual within the HELCOM COMBINE.

View HELCOM phytoplankton sampling stations via an interactive data and map service.

Protocols of PEG meetings

HELCOM Baltic Sea environment fact sheets and reports about phytoplankton, produced by PEG:

Image gallery of Baltic phytoplankton species

HELCOM PEG image gallery at the Nordic Microalgae web site

IOW-photo gallery of phytoplankton

Baltic Sea Portal – Photos of Baltic Sea Phytoplankton

Checklist of phytoplankton in the Skagerrak-Kattegat

Polish image gallery

Other useful links to phytoplankton web sites

On-line database on cyanobacterial genera

Dinoflagellates – Centers of Excellence for Dinophyte Taxonomy

Plankton net

Contracting Parties and laboratories

  • Denmark
  • Estonia
  • Finland
  • Germany
  • Latvia
  • Lithuania
  • Poland
  • Russia
  • Sweden

For more information, please contact:

Ms. Jannica Haldin
Professional Secretary​
(Gear, State and Conservation)
Tel: +358 40 485 590