The datasets in this collection were compiled to support the Second HELCOM Holistic Assessment of the Ecosystem Health of the Baltic Sea (HOLAS 2). The assessment provides a comprehensive evaluation of the state of the Baltic Sea ecosystem based on data collected during the 2011–2016 assessment period. The datasets cover environmental status, biodiversity, eutrophication, hazardous substances, human activities, pressures, and related ecosystem components used in regional assessments under the ecosystem approach to management. The information contributes to HELCOM's State of the Baltic Sea assessment and supports regional policy implementation, environmental reporting, and marine management across the Baltic Sea region. Avaialble datasets are listed below and can be downloaded as a full package in the link.

Biodiversity

Availability of deep water habitat, based on occurrence of H2S 2011-2016 HOLAS 2

Baltic Esker islands 1610 2011-2016 HOLAS 2

Boreal Baltic islets and small islands 1620 2011-2016 HOLAS 2

Breeding areas for birds HOLAS 2

Charophyte distribution 2011-2016 HOLAS 2

Circalittoral hard substrate 2016 HOLAS 2

Circalittoral mixed substrate 2016 HOLAS 2

Circalittoral mud 2016 HOLAS 2

Circalittoral sand 2016 HOLAS 2

Coastal lagoons 1150 2011-2016 HOLAS 2

Cod abundance HOLAS 2

Estuaries 1130 2011-2016 HOLAS 2

Fucus distribution 2011-2016 HOLAS 2

Furcellaria lumbricalis distribution 2011-2016 HOLAS 2

Grey seal distribution HOLAS 2

Harbour porpoise distribution HOLAS 2

Harbour seal distribution HOLAS 2

Herring abundance HOLAS 2

Infralittoral hard substrate 2016 HOLAS 2

Infralittoral mixed substrate 2016 HOLAS 2

Infralittoral mud 2016 HOLAS 2

Infralittoral sand 2016 HOLAS 2

Large shallow inlets and bays 1160 2011-2016 HOLAS 2

Mudflats and sandflats 1140 2011-2016 HOLAS 2

Mytilus distribution 2011-2016 HOLAS 2

Productive surface waters Chl-a 2011-2016 HOLAS 2

Reefs 1170 2011-2016 HOLAS 2

Ringed seal distribution HOLAS 2

Sandbanks 1110 2011-2016 HOLAS 2

Sprat abundance HOLAS 2

Submarine structures made by leaking gas 1180 2011-2016 HOLAS 2

Wintering areas for birds HOLAS 2

Zostera marina distribution 2011-2016 HOLAS 2

Indicators and assessments

Abundance of coastal fish key functional groups - cyprinids mesopredators 2018 HOLAS 2

Abundance of coastal fish key functional groups - piscivores 2018 HOLAS 2

Abundance of coastal fish key functional groups 2018 data point HOLAS 2

Abundance of coastal fish key functional groups 2018 data polygon HOLAS 2

Abundance of key coastal fish species 2018 data point HOLAS 2

Abundance of key coastal fish species 2018 data polygon HOLAS 2

Abundance of key coastal fish species 2018 HOLAS 2

Abundance of salmon spawners and smolt 2018 data HOLAS 2

Abundance of salmon spawners and smolt 2018 HOLAS 2

Abundance of sea trout spawners and parr 2018 data HOLAS 2

Abundance of sea trout spawners and parr 2018 HOLAS 2

Abundance of waterbirds in the breeding season - benthic feeders 2018 HOLAS 2

Abundance of waterbirds in the breeding season - grazing feeders 2018 HOLAS 2

Abundance of waterbirds in the breeding season - pelagic feeders 2018 HOLAS 2

Abundance of waterbirds in the breeding season - surface feeders 2018 HOLAS 2

Abundance of waterbirds in the breeding season - wading feeders 2018 HOLAS 2

Abundance of waterbirds in the breeding season 2018 data HOLAS 2

Abundance of waterbirds in the breeding season 2018 HOLAS 2

Abundance of waterbirds in the wintering season - benthic feeders 2018 HOLAS 2

Abundance of waterbirds in the wintering season - grazing feeders 2018 HOLAS 2

Abundance of waterbirds in the wintering season - pelagic feeders 2018 HOLAS 2

Abundance of waterbirds in the wintering season - surface feeders 2018 HOLAS 2

Abundance of waterbirds in the wintering season - wading feeders 2018 HOLAS 2

Abundance of waterbirds in the wintering season 2018 data HOLAS 2

Abundance of waterbirds in the wintering season 2018 HOLAS 2

Chlorophyll-a 2018

Cyanobacterial bloom index 2018

Diatom-dinoflagellate ratio 2018 data HOLAS 2

Diatom-dinoflagellate ratio 2018 HOLAS 2

Dissolved inorganic nitrogen 2018

Dissolved inorganic phosphorus 2018

Distribution of Baltic seals - grey seal 2018 data HOLAS 2

Distribution of Baltic seals - grey seal 2018 HOLAS 2

Distribution of Baltic seals - harbour seal 2018 data HOLAS 2

Distribution of Baltic seals - harbour seal 2018 HOLAS 2

Distribution of Baltic seals - ringed seal 2018 HOLAS 2

Eutrophication assessment in-situ data 2018

Hexabromocyclodocecane HBCDD 2018 biota data

Hexabromocyclodocecane HBCDD 2018 sediment data

Hexabromocyclododecane HBCDD 2018

Integrated biodiversity status assessment - benthic habitats 2018 HOLAS 2

Integrated biodiversity status assessment - fish 2018

Integrated biodiversity status assessment - grey seal 2018

Integrated biodiversity status assessment - harbour seal 2018

Integrated biodiversity status assessment - pelagic habitats 2018

Integrated biodiversity status assessment - ringed seal 2018

Integrated biodiversity status assessment - seals 2018

Integrated contamination status assessment 2018

Integrated eutrophication status assessment 2018

Integrated eutrophication status assessment 2018 - Direct effects

Integrated eutrophication status assessment 2018 - Indirect effects

Integrated eutrophication status assessment 2018 - Nutrient levels

Metals Cadmium 2018

Metals Cadmium 2018 biota data

Metals Cadmium 2018 sediment data

Metals Cadmium 2018 water data

Metals Lead 2018

Metals Lead 2018 biota data

Metals Lead 2018 sediment data

Metals Lead 2018 water data

Metals Mercury 2018

Metals Mercury 2018 biota data

Nutritional status of seals 2018 data HOLAS 2

Nutritional status of seals 2018 HOLAS 2

Operational oil spills from ships 2018

Operational oil spills from ships 2018 data

Oxygen debt 2018

Perfluorooctane sulphonate PFOS 2018

Perfluorooctane sulphonate PFOS 2018 biota data

Perfluorooctane sulphonate PFOS 2018 water data

Polyaromatic hydrocarbons PAH and their metabolites 2018

Polyaromatic hydrocarbons PAH and their metabolites 2018 biota data

Polyaromatic hydrocarbons PAH and their metabolites 2018 sediment data

Polybrominated diphenyl ethers PBDE 2018

Polybrominated diphenyl ethers PBDE 2018 biota data

Polybrominated diphenyl ethers PBDE 2018 sediment data

Polychlorinated biphenyls PCB and dioxins and furans 2018

Polychlorinated biphenyls PCB and dioxins and furans 2018 biota data

Population trends and abundance of seals - Grey seal 2018 data HOLAS 2

Population trends and abundance of seals - Grey seal 2018 HOLAS 2

Population trends and abundance of seals - Harbour seal 2018 data HOLAS 2

Population trends and abundance of seals - Harbour seal 2018 HOLAS 2

Population trends and abundance of seals - Ringed seal 2018 HOLAS 2

Radioactive substances Cesium-137 in fish 2018 data

Radioactive substances Cesium-137 in flatfish 2018

Radioactive substances Cesium-137 in herring 2018

Radioactive substances Cesium-137 in seawater 2018

Radioactive substances Cesium-137 in seawater 2018 data

Reproductive disorders - malformed embryos of amphipods 2018

Reproductive disorders - malformed embryos of amphipods 2018 data

Reproductive status of seals 2018 data HOLAS 2

Reproductive status of seals 2018 HOLAS 2

Seasonal succession of dominating phytoplankton groups 2018 data HOLAS 2

Seasonal succession of dominating phytoplankton groups 2018 HOLAS 2

State of the soft-bottom macrofauna community 2018 data HOLAS 2

State of the soft-bottom macrofauna community 2018 HOLAS 2

TBT and imposex 2018

TBT and imposex 2018 biota data

TBT and imposex 2018 sediment data

TBT and imposex 2018 water data

Total nitrogen 2018

Total phosphorus 2018

Trends in arrival of new non-indigenous species 2018 HOLAS 2

Trends in arrival of new non-indigenous species data 2018 HOLAS 2

Water clarity 2018

White-tailed eagle productivity 2018

Zooplankton mean size and total stock MSTS 2018 data HOLAS 2

Zooplankton mean size and total stock MSTS 2018 HOLAS 2

Pressures

Baltic Sea Impact Index BSII

Baltic Sea Pressure Index BSPI

Bathing sites HOLAS 2

Beach litter on monitored sites plastic pieces/100m

Bridges and other constructions HOLAS 2

Changes to hydrological conditions HOLAS 2

Coastal defense HOLAS 2

Deposit of dredged material sites areas 2011-2016 HOLAS 2

Deposit of dredged material sites points 2011-2016 HOLAS 2

Discharge of warm water from nuclear power plants HOLAS 2

Discharges of radioactive substances from NPPs HOLAS 2

Disturbance of species due to human presence HOLAS 2

Dredging areas 2011-2016 HOLAS 2

Dredging points 2011-2016 HOLAS 2

Extraction of fish - Cod extraction landings HOLAS 2

Extraction of fish - Herring extraction landings HOLAS 2

Extraction of fish - Sprat extraction landings HOLAS 2

Extraction of mammals - Seal hunting HOLAS 2

Extraction of sand and gravel 2011-2016 HOLAS 2

Extraction of seabirds - Bird hunting HOLAS 2

Finfish mariculture HOLAS 2

Fish extraction commercial fisheries - cod HOLAS 2

Fish extraction commercial fisheries - herring HOLAS 2

Fish extraction commercial fisheries - sprat HOLAS 2

Fishing intensity 2011-2016 average subsurface swept area ratio

Fossil fuel energy production HOLAS 2

Furcellaria harvesting HOLAS 2

Game hunting of seabirds HOLAS 2

Harbours HOLAS 2

Hunting of seals - Grey seal HOLAS 2

Hunting of seals - Harbour seal HOLAS 2

Hunting of seals - Ringed seal HOLAS 2

Hydropower dams HOLAS 2

Illegal oil discharges HOLAS 2

Input of continuous anthropogenic sound HOLAS 2

Input of hazardous substances HOLAS 2

Input of heat HOLAS 2

Input of impulsive anthropogenic sound HOLAS 2

Introduction of non-indigenous species and translocations HOLAS 2

Introduction of radionuclides HOLAS 2

Land claim HOLAS 2

Mussel and scallop dredging

Oil and Gas Refineries HOLAS 2

Oil platforms HOLAS 2

Oil slicks and spills HOLAS 2

Oil terminals HOLAS 2

Physical disturbance HOLAS 2

Physical loss HOLAS 2

Polluting ship accidents HOLAS 2

Potential cumulative impacts on benthic habitats

Predator control of seabirds HOLAS 2

Recreational fishing

Relative distribution of nutrient concentration - Total Nitrogen HOLAS 2

Relative distribution of nutrient concentration - Total Phosphorus HOLAS 2

Shellfish mariculture areas HOLAS 2

Shellfish mariculture points HOLAS 2

Shipping density 2011-2015 HOLAS 2

Urban land use HOLAS 2

Watercourse modification HOLAS 2

Wind farms HOLAS 2