Non-indigenous species and IMAP
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IMAP is how the Contracting Parties to the Barcelona Convention measure the state of the Mediterranean Sea and Coast. It sets the common indicators every country monitors, the methods it uses and the criteria for judging Good Environmental Status (GES). Non-indigenous species are covered by Ecological Objective 2 and Common Indicator 6.
- 2008Ecosystem Approach agreedCOP 15 · IG.17/6
- 2013GES definitions and targetsCOP 18 · IG.21/3
- 2016IMAP adoptedCOP 19 · IG.22/7
- 2017First MED QSRCOP 20 · IG.23/6
- 2023Second MED QSRCOP 23 · IG.26/3
- 2025Third cycle adoptedCOP 24 · IG.27/6
- 2026–2035Third IMAP cycle11 objectives · 43 indicators
Eleven objectives, three monitoring clusters
IMAP groups its work into three clusters: Biodiversity and Non-Indigenous Species, Pollution and Marine Litter, and Coast and Hydrography. SPA/RAC coordinates the biodiversity and NIS cluster, MED POL the pollution cluster, and PAP/RAC the coast cluster.
How IMAP defines good status for non-indigenous species
- Ecological Objective 2
- Non-indigenous species introduced by human activities are at levels that do not adversely alter the ecosystem.
- Operational objective 2.1
- Invasive non-indigenous species introductions are minimized.
- Common Indicator 6
- Trends in abundance, temporal occurrence and spatial distribution of non-indigenous species, particularly invasive non-indigenous species, notably in risk areas, in relation to the main vectors and pathways of spreading.
- GES definition
- Decreasing abundance of introduced NIS in risk areas.
- GES target
- Abundance of NIS introduced by human activities reduced to levels giving no detectable impact.
In IMAP, a non-indigenous species is a species, subspecies or lower taxon introduced outside its natural range and outside its natural dispersal potential. Invasive alien species are the subset of established NIS that spread and affect biodiversity, ecosystem functioning, socio-economic values or human health.
Where countries look for new arrivals
NIS monitoring is trend monitoring, and it follows a risk-based approach. Instead of sampling the whole coast, countries survey the introduction hot spots where new species are most likely to appear first. That gives a basin-wide picture from a relatively small number of stations, provided the same sites are surveyed every period.
Rapid Assessment Surveys
The main method: a Rapid Assessment Survey in hot-spot areas at least once a year. Countries with the resources are encouraged to add environmental DNA (eDNA) surveys.
Citizen surveys
During the third cycle, UNEP/MAP will develop citizen-survey guidance for NIS, a low-cost method that also builds public awareness and participation.
1,011 non-indigenous species recorded in Mediterranean waters
According to the 2023 Mediterranean Quality Status Report (MED QSR), 1,011 validated non-indigenous species have been recorded in Mediterranean waters, of which 748 are considered established, an establishment rate of nearly 74%.
Judged by sub-region, every six years
CI6 can be calculated for the whole basin or for a country, but it is most meaningful at the level of the four EcAp sub-regions, and within them for each country's national part. The assessment period follows the 6-year cycle already used by EU countries under the Marine Strategy Framework Directive.
Threshold values are not set yet
Neither the EU nor the Mediterranean has a threshold for new introductions. The recommended approach is a percentage reduction in new NIS, set separately for each sub-region and based on data from 2000 onwards, when the rate of new records rose sharply.
What still has to be agreed
Which species groups count in the trend, and how impacts are taken into account. The next step is to develop criteria and targets for vulnerable species and habitats, coordinated with EO1 and EO6.
Where MAMIAS fits in
At the start of each IMAP phase, every Contracting Party updates its list of invasive alien species to monitor. The decision names MAMIAS first among the regional databases that list should build on.
“…the Marine Mediterranean Invasive Alien Species database, (MAMIAS)…”Decision IG.27/6, Annex II, paragraph 66
Monitoring data then go to the IMAP Info System, which accepts data for 18 common indicators, CI6 among them, through 30 information standards. Its published data are open to the public.
- UNEP/MAP, Decision IG.27/6, Ecosystem Approach (EcAp) Policy and Roadmap 2026–2035 and Integrated Monitoring and Assessment Programme for the Mediterranean Sea and Coast (IMAP), COP 24, Cairo, 2025. UNEP/MED IG.27/21. Document
- UNEP/MAP, Decision IG.22/7, Integrated Monitoring and Assessment Programme of the Mediterranean Sea and Coast and Related Assessment Criteria, COP 19, Athens, 2016.
- UNEP/MAP, 2023 Mediterranean Quality Status Report (MED QSR), for all figures on non-indigenous species. medqsr2023.info-rac.org