Other effective area-based conservation measures (OECMs) are a new conservation approach, separate from protected areas, where conservation is achieved mainly as a by-product of other management. A definition was agreed at the 14th Conference of Parties of the Convention on Biological Diversity in 2018:

"A geographically defined area other than a Protected Area, which is governed and managed in ways that achieve positive and sustained long-term outcomes for the in-situ conservation of biodiversity, with associated ecosystem functions and services and where applicable, cultural, spiritual, socio–economic, and other locally relevant values."

This definition covers three main cases:

1. ‘Ancillary conservation’: areas delivering in-situ conservation as a by-product of management, even though biodiversity conservation is not an objective (e.g. some military training grounds, protected marine war graves and freshwater protection zones).

2. ‘Secondary conservation’: active conservation of an area where biodiversity outcomes are only a secondary management objective (e.g. some conservation corridors).

3. ‘Primary conservation’: areas meeting the IUCN definition of a protected area, but where the governance authority (e.g. community, Indigenous peoples’ group, religious group, private landowner) does not wish the area reported as a protected area.

The above categories are not precise and OECMs need to be judged on a case-by-case basis. OECMs should only be recognised in areas where there is significant biodiversity, and which meet the CBD criteria. An area set aside to ensure clean drinking water could be a form of ancillary conservation, or possibly secondary conservation if it included some conservation aims within its management strategy, or possibly neither if the water protection offered few biodiversity benefits.

It is important to note that, in order to comply with the OECM criteria, areas identified as ‘potential OECMs’ should demonstrate relevant ecological standards and not just an improvement in the ecological condition. For instance, the OECM’s definition requires the ‘in-situ conservation of biodiversity’ and the CBD defines ‘in-situ conservation’ in its Article 2 as ‘the conservation of ecosystems and natural habitats and the maintenance and recovery of viable populations of species in their natural surroundings and, in the case of domesticated or cultivated species, in the surroundings where they have developed their distinctive properties’. Furthermore, the IUCN (2019) states that OECMs ‘…should deliver biodiversity outcomes of comparable importance to, and complementary with, those of protected areas’. COP Decision 14/8 (CBD, 2018) indicates that the recognition of OECMs:…is expected to include the identification of the range of biodiversity attributes for which the site is considered important (e.g. communities of rare, threatened or endangered species, representative natural ecosystems, range restricted species, key biodiversity areas, areas providing critical ecosystem functions and services, areas for ecological connectivity).

Because they are based on existing management, OECMs are recognised rather than designated, i.e. they are existing management systems that already provide effective biodiversity conservation. However, some places identified as ‘potential OECMs’ which almost but not quite meet the definition might require some management changes to reach full OECM status.

The European Environment Agency comissioned a scoping report to "Assess the potential of other effective area-based conservation measures as a driver for landscape-level conservation and connectivity in the EU". The report was created by UN Environment Programme World Conservation Monitoring Centre (UNEP-WCMC), the Institute for European Environment Policy (IEEP), and Trinomics under a specific contract.

  • The Report can be downloaded from here
  • The Annex to the Report can be downloaded from here
    The Annex, include examples from Spain and Finland

OECMs are still relatively unknown in EU policy development and implementation and there is an urgent need to provide insight so that guidance can be offered to help EU Member States to assess which measures to prioritize and report on OECMs in their National Strategies and Action Plans under the CBD and in implementation of the EU Biodiversity Strategy for 2030. This scoping study was commissioned by the European Environment Agency (EEA) to review the application of recently established international OECM guidelines in the EU policy context, provide such insight and identify priorities for future work to implement and report OECMs in the EU.