Ecosystem Extent Accounts – Marine 2024

What are Ecosystem Accounts?

The System of Environmental Economic Accounting - Ecosystem Accounting (SEEA-EA) is a spatially-based, integrated statistical framework for organizing biophysical information about ecosystems, measuring ecosystem services, tracking changes in ecosystem extent and condition, valuing ecosystem services and assets and linking this information to measures of economic and human activity. It is an integrated statistical framework adopted by the United Nations Statistical Commission.

The SEEA-EA outlines five sets of ecosystem accounts:

1. Ecosystem extent accounts
2. Ecosystem condition accounts
3. Ecosystem services (physical flow)
4. Ecosystem services (monetary flow)
5. Monetary ecosystem asset accounts

As part of a recent amendment to Regulation (EU) No 691/2011 on environmental economic accounts, it will be mandatory to report ecosystem extent, condition and services (physical flow) accounts in line with SEEA-EA, although for Marine Ecosystems only the extent at level 1 of the EU Ecosystem Typology is mandatory. The monetary flow of ecosystem services and the monetary value of ecosystem assets will not need to be accounted for under the new regulation. Mandatory reporting by member states will commence in 2026.

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Data

The ecosystem extent accounts reported in this release were produced using a compiled ecosystem extent map for the reference year 2024. This map was created using a wide range of EU and national level geospatial data (Table 4.1).

Ecosystem classification and mapping

Data preparation

A number of pre-processing steps were necessary in order to compile and merge the wide range of different source data used to produce the final ecosystem extent map. Firstly, EUSeaMap – the base map onto which all other data were layered – was clipped to the EAA and reprojected to the European LAEA projection/ EPSG:3035. Then, all other source data were formatted and re-projected to EPSG:3035 to ensure compatibility with EUSeaMap. 

Data merging

Merging of different data sources involves successive ‘layering’ of each dataset on top of the next to produce a map that uses the most accurate and up-to-date data. This can also be thought of as ‘gap-filling’, whereby the first map is added to a blank canvas after which the next is used to update and/or fill gaps in the previous. The priority assigned to each dataset depends on three main attributes of the source data, including the year for which the data refers (i.e. data age), the degree of correspondence between the source data and the ecosystem type definition, and accuracy (i.e. expected level of error in the source data). 

Classifications

The EU Ecosystem Typology (EUET) was developed by Eurostat as a common classification to harmonize the reporting on ecosystem accounts in the EU. It uses three levels of increasing ecological detail to classify European ecosystems, see Table 4.2 and 4.3.

At level 1, the EU ecosystem typology is an updated MAES ecosystem typology, and is defined in Annex IX of Regulation (EU) 691/2011 on the European environmental-economic accounts and has been adopted as mandatory reporting on ecosystem extent to Eurostat.

At level 2, the main ecosystem types are further differentiated into sub-types in a manner that is relevant to ecosystem service and condition modelling and reporting. The breakdown at level 2 can be submitted to Eurostat as part of the reporting under the Regulation, on a voluntary basis.

Level 3 presents an additional, more detailed layer to support ecosystem service and condition modelling and national uses.

The marine ecosystem types are mapped according to an agreed step-wise classification workflow:

1. Anthropogenic Structures & Modified Ecosystems (12.8) are to be classified first.
2. In the second step, areas below the low-tide mark with a >25% coverage by sessile biota are to be assigned exclusively into classes Marine Macrophyte Communities (12.1) or Biogenic Reefs & Animal Forests (12.2), respectively, regardless of water depth or abiotic characteristics of the sea bed.
3. In the third step, the sublittoral zone (12.3 and 12.4), Continental & Island Slope (12.5 ) and Deep-Sea Ecosystems (12.6) are distinguished.
4. In the fourth step, the sublittoral zone is classified based on sediment class size into Sublittoral Sediments (12.3) and Sublittoral Rocky Substrates (12.4).
5. In the fifth step, Coastal Inlets (12.7) may be distinguished. They represent mosaic ecosystems often comprising a large share of other level 2 ecosystem types (e.g. 12.1, 12.2, 12.3 or 12.4), hence their reporting presumes that countries had not already classified the same area in one of the other classes in the previous steps. This would lead to double counting and must be avoided. In practice, in Ireland's case, the area of Coastal Inlets not already classified in one of the previous steps is very small.

Residual areas

Some areas within the marine EEA could not be classified any further, so are mapped as 12. Marine Ecosystems. Similarly, some areas could be mapped only to level 2 of the typology, and are mapped as e.g. Sublittoral Sediments n.f.d. - not further defined.

Final map

The result of classifying all ecosystem types based on the different source data was a compiled raster map. To maintain coherence with the terrestrial and transitional map, it was aggregated to a resolution of 100 × 100m (1 hectare). 

Validation and accuracy

Validation

A validation exercise was carried out to test agreement between a modified Folk-9 substrate map derived from EUNIS Level 3 habitats and point data from measured sediment samples compiled from INFOMAR surveys.

Within the sediment-only subset (5,939 points), 69.45 percent of samples matched the mapped Folk-9 class exactly, increasing to 85.72 percent when adjacent sediment classes were considered equivalent. Across the broader overlap subset (6,346 points), where classes were represented in both datasets, exact agreement was 67.59 percent and increased to 86.48 percent under the ±1-class tolerance rule.

Possible sources of error

This ecosystem extent map combines data from a range of survey types carried out at different scales, over different time periods, and for different purposes. This means that there are some limitations that must be kept in mind when using the data:

• Survey age - some input datasets combine survey data from surveys carried out over a number of years, and so the ecosystem may have changed since it was surveyed.
• Survey scale - the scale of the survey used for an input dataset can have an impact on the level of detail available in the final dataset, and on the minimum mapping unit for that dataset.
• Survey purpose - the level of detail produced by a survey may be sufficient for the needs of that survey, but may not provide enough information to enable classication to level 2 or level 3 of the EUET.
• Survey classification - a range of different classifications were used in the input datasets. These were cross-walked from the original to EUNIS 2012, and from there to the EUET. In some cases no direct cross-walk was achievable, and expert judgement was employed.

Future updates

Spatial data on marine ecosystems are not regularly updated. Marine ecosystems, therefore, are mapped based on best and most recently available data. This means that future iterations of these accounts may have changes that reflect improved surveying efforts of marine habitats, rather than real changes from one ecosystem to another.