Invasive Alien Species in Mediterranean Marine Ecosystems

Invasive alien species (IAS) have transformed the biological composition, functioning and services of Mediterranean marine ecosystems. Introduced via shipping vectors (ballast water, hull fouling), aquaculture escapes and the Lessepsian corridor of the Suez Canal, these species range from macroalgae and invertebrates to herbivorous fish. Once established, IAS outcompete native taxa, alter habitat structure—such as the conversion of algal beds to barrens—and disrupt trophic networks. Climate warming amplifies establishment success, enabling tropical and subtropical species to colonise cooler northern and western sectors. Ecological consequences include reductions in native biodiversity, shifts in ecosystem functioning and novel food-web configurations, while socioeconomic impacts manifest in fouling of infrastructures, losses in fisheries yields and management costs. A trait-based perspective has emerged to assess functional vulnerability, and mapping cumulative impacts guides the identification of hotspots. Integrated management combines early detection with horizon scanning, risk assessments and biosecurity measures, alongside innovative uses of invasive biomass to mitigate environmental and economic burdens.

Research from Nature Portfolio

Recent studies have quantified long-term changes in benthic functional composition following mass mortality events from 1986 to 2020. By compiling ecological traits across nearly 400 species, researchers identified over 200 functional entities and demonstrated that calcifying organisms and slow-growing forms suffer disproportionately high mortality. Results reveal a 19 percent increase in trait volume vulnerability and a temporary loss of over 10 percent of functional trait volume in the past five years, signalling a heightened risk of rapid ecological transformation in Mediterranean benthic communities.

Invasive Alien Species in Mediterranean Marine Ecosystems publication trend

The graph below shows the total number of articles in invasive alien species in mediterranean marine ecosystems across all publications each year (not limited to Nature Index journals).

Technical terms

Invasive Alien Species: Organisms introduced beyond their native range that establish, spread and cause ecological, economic or health impacts.

Lessepsian species: Non-indigenous Red Sea organisms entering the Mediterranean via the Suez Canal.

Functional trait: Morphological, physiological or behavioural characteristic influencing species performance and ecosystem processes.

Mass mortality event: Large-scale, abrupt die-off of organisms typically induced by disease, temperature extremes or other acute stressors.

Novel ecosystem: Ecosystem comprising new combinations of native and non-native species shaped by anthropogenic and environmental change.

References

1. Vulnerability of benthic trait diversity across the Mediterranean Sea following mass mortality events. Nature Communications (2025).
2. A Concise Review on the Potential Applications of Rugulopteryx okamurae Macroalgae. Marine Drugs (2023).
3. Mediterranean non indigenous species at the start of the 2020s: recent changes. Marine Biodiversity Records (2020).
4. Impacts of invasive alien marine species on ecosystem services and biodiversity: a pan-European review. Aquatic Invasions (2014).
5. Mapping the impact of alien species on marine ecosystems: the Mediterranean Sea case study. Diversity and Distributions (2016).
6. The enlargement of the Suez Canal—Erythraean introductions and management challenges. Management of Biological Invasions (2017).
7. Bioinvasion impacts on biodiversity, ecosystem services, and human health in the Mediterranean Sea. Aquatic Invasions (2022).
8. Native biodiversity collapse in the eastern Mediterranean. Proceedings of the Royal Society B (2021).
9. Gateways to alien invasions in the European seas. Aquatic Invasions (2014).
10. Prioritizing marine invasive alien species in the European Union through horizon scanning. Aquatic Conservation Marine and Freshwater Ecosystems (2020).