The community characteristics is monitored each year in accordance with the HELCOM methodology, including parameters necessary for the assessment of benthic habitats. Monitoring includes sampling of macrozoobenthos at 16 stations and macrophyte and angiosperms at places of occurrence within PMA. For the transitional and coastal waterbodies monitoring will be carried out for 19 monitoring points in 2020-2021 and 11 monitoring points in 2022-2025 in accordance with the WFD monitoring programme, carried out under the surface water monitoring programme for the years 2020-2025 ("Strategic State Environmental Monitoring Programme for the years 2020-2025"), approved by the Competent Minister of Climate in 2020 and the surface water executive programme for a specific year of research approved annually by the Chief Inspector of Environmental Protection

The abundance and/or biomass of species is monitored each year in accordance with the HELCOM methodology, including parameters necessary for the assessment of benthic habitats. Monitoring includes sampling of macrozoobenthos at 16 stations and macrophyte and angiosperms at places of occurrence within PMA. For the transitional and coastal waterbodies monitoring will be carried out for 19 monitoring points in 2020-2021 and 11 monitoring points in 2022-2025 in accordance with the WFD monitoring programme, carried out under the surface water monitoring programme for the years 2020-2025 ("Strategic State Environmental Monitoring Programme for the years 2020-2025"), approved by the Competent Minister of Climate in 2020 and the surface water executive programme for a specific year of research approved annually by the Chief Inspector of Environmental Protection

Monitoring is carried out to meet the requirements of the Birds Directive as well as the Commission Directive (EU) 2017/845 of 17 May 2017 and criteria laid down in Commission Decision (EU) 2017/848 of 17 May 2017 for Descriptor D1. The results of the monitoring are also used for the work of the HELCOM group.

So far, three species have been monitored under this program: Cormorant, Sandwich Tern, and Dunlin. New species have been added to the monitoring program since 2020: Ringed Plover, Little Tern, Oystercatcher, and Shelduck.

Harbour porpoise will be monitored at three locations including two monitored in 2016-2018, i.e. Pomeranian Bay and Ławica Stilo and at one new location - Gulf of Gdańsk. In the case of Pomeranian Bay location all five monitoring stations will be deployed in the same locations as in the pilot research and SAMBAH project. In the case of Ławica Stilo location 4 monitoring stations will be identical to the ones from the pilot monitoring and SAMBAH project. The locations of the 5th station will be subject to the approval of Maritime Office. In the case of the Gulf of Gdańsk location, four stations will be equivalent of those designated within the SAMBAH project, while one station (station code: CPOD15) will be designated in the Puck Bay region, taking into account the specificities of this area (fisheries, shipping, tourism) and in agreement with maritime administration. In order to maintain regional coherence, the timeline for harbour porpoise monitoring should be compliant with the recommendations of the expert group on marine mammals HELCOM EXPERT GROUP ON MARINE MAMMALS – HELCOM EG MAMA (former name of the group - HELCOM SEAL), which are currently in the consultation stage. According to the recommendations of the HELCOM MAMA group the monitoring will be performed in accordance with one of two proposed methodologies. One methodology recommends to conduct monitoring for at least 24 months over the six-year period covered by the assessment, but not earlier than 3 years after the end of the previous monitoring. The second methodology recommends to conduct monitoring twice over a six-year period, each of research should last 12 months. The monitoring was planned in accordance with the initial recommendation of this group, i.e. 1 year of measurements every 3 years (HELCOM 2018). Currently the SAMBAH II project is in the planning stage, the project will cover the entire Baltic Sea area. At the time of development of the current update of the monitoring programme the starting date of research is not known. It is subject to the submission of an application to LIFE funding instrument for the 2021-2027 funding period for the funding of SAMABAH II project. The monitoring planned under SAMBAH II will include the area covered by the SAMBAH project and will be extended to research of areas deeper than 80 m. Within the SAMBAH II project, it is also planned to identify juveniles. To this end, within the implementation of one of the tasks of SAMBAH II, a model will be adapt

Monitoring of grey seal in Polish Marine Areas will be carried out each year, during which performed observations will allow to detect potential reproduction of this species and determine the abundance of the population from Vistula Mouth - Przekop (the only confirmed haul-out site on the Polish coast, determined at the time of the development of current update of the monitoring programme of marine waters). In the case of determination and confirmation of a new haul-out site during the current monitoring programme of marine waters it will be included in the monitoring. Monitoring of grey seal will be carried out in accordance with the recommendations contained in the document of the HELCOM MAMA expert group "Guidelines to the monitoring of seals" (HELCOM 2018) and the latest edition of the guideline for the monitoring of grey seal, posted on the Chief Inspectorate of Environmental Protection website in a subpage dedicated to monitoring of marine species and habitat (http://morskiesiedliska.gios.gov.pl/pl/do-pobrania/przewodniki-metodyczne). In the case of aircraft surveys, the methodology contained in the above documents will be used.

Monitoring of harbour seal is carried out in parallel with the monitoring of grey seal, i.e. the collection of information on the occurrence of harbour seal takes place during the monitoring of grey seal. In addition, in each monitoring year, one observation flight will be performed in August, i.e. during the harbour seal moulting period. The monitoring of harbour seal will include species identification of the other two seal species that may occur on the Polish coast, i.e. grey seal (constantly present) and ringed seal (occasionally occurring). Monitoring of harbour seal will be carried out in accordance with the recommendations of the HELCOM MAMA expert group contained in the document "Guidelines to the monitoring of seals" (HELCOM 2018) and the latest edition of the guideline for the monitoring of harbour seal, posted on the Chief Inspectorate of Environmental Protection website in a subpage dedicated to monitoring of marine species and habitat (http://morskiesiedliska.gios.gov.pl/pl/do-pobrania/przewodniki-metodyczne). The research will be carried out in accordance with the conditions described in the permits of relevant offices.

The ichthyological monitoring of the Polish Exclusive Economic Zone in the deepwater zone of Polish marine area has been carried out as a part of national environmental monitoring since 2011, based on data from BITS (Baltic International Trawl Surveys). BITS consist of cruises of particular Baltic countries being temporally and spatially coordinated by ICES. BITS methodology establishes use of standarized bottom trawl of the same design for scientific catches and use of the same research method for hauling sites sampling, data collection and uploading of collected data to the ICES common database - DATRAS, supplemented with measurement and ichthyological analysis of all fish species (including non-commercial).

Monitoring in transitional waterbodies is carried out once every 3 years, except for Puck Lagoon, Vistula Lagoon and Puck Bay, where monitoring is conducted annually. Fish monitoring in transitional waterbodies includes an analysis of the following elements: • determination of weight and abundance of all fish species present in the catch; • ichthyological analysis of a representative sample of all fish species present in the catch, taking into account their length, individual weight, sex, gonad maturity stage, stomach degree fullness and age of individual fish. The monitoring also includes the analysis of physico-chemical water parameters necessary for assessing the ecological status of transitional waters.

Fish monitoring in coastal waterbodies includes an analysis of the following elements: • determination of weight and abundance of all fish species present in the catch; • ichthyological analysis of a representative sample of all fish species present in the catch, taking into account their length, individual weight, sex, gonad maturity stage, stomach degree fullness and age of individual fish. The monitoring also includes the analysis of physico-chemical water parameters necessary for assessing the ecological status of coastal waters.

Fish monitoring in offshore shallow water areas includes an analysis of the following elements: • determination of weight and abundance of all fish species present in the catch; • ichthyological analysis of a representative sample of all fish species present in the catch, taking into account their length, individual weight, sex, gonad maturity stage, stomach degree fullness and age of individual fish. The monitoring also includes the analysis of physico-chemical water parameters.

Monitoring programme of pelagic habitats – community characteristics includes the determination of the characteristics and variability of phytoplankton and zooplankton communities in PMA. Monitoring is carried out annually in 10 locations in accordance with the HELCOM guidelines. For the transitional and coastal waterbodies monitoring will be carried out for 19 monitoring points in 2020-2021 and 11 monitoring points in 2022-2025 in accordance with the WFD monitoring programme, carried out under the surface water monitoring programme for the years 2020-2025 ("Strategic State Environmental Monitoring Programme for the years 2020-2025"), approved by the Competent Minister of Climate in 2020 and the surface water executive programme for a specific year of research approved annually by the Chief Inspector of Environmental Protection.

In scope of phytoplankton blooms, data on frequency and extent of blooms collected within the monitoring programme of pelagic habitats – community characteristics will be supplemented with information on chlorophyll a concentration in the water column collected from 23 stations located in PMA. The frequency of measurements is 6 times a year except for high frequency station (ZP6) which should be sampled 12 times a year. Data on phytoplankton blooms and chlorophyll a concentration will be supplemented with available open source remote sensing products (from satellite systems). For the transitional and coastal waterbodies monitoring will be carried out for 19 monitoring points in 2020-2021 and 11 monitoring points in 2022-2025 in accordance with the WFD monitoring programme, carried out under the surface water monitoring programme for the years 2020-2025 ("Strategic State Environmental Monitoring Programme for the years 2020-2025"), approved by the Competent Minister of Climate in 2020 and the surface water executive programme for a specific year of research approved annually by the Chief Inspector of Environmental Protection.