Reconsidering the role of introduced species in the climate-affected and highly invaded eastern Mediterranean

Bioinvasions are considered mostly as a biodiversity and conservation hazard, but in specific situations, introduced species can bring ecological or socioeconomic benefits. We assessed the social–ecological role of marine introduced species in the eastern Mediterranean Sea—a global hotspot of bioinvasions and extirpations—and their potential relevance for achieving conservation and sustainability targets set by the Kunming–Montreal Global Biodiversity Framework (GBF). The adverse effects of introduced species include predation and competition with native species, alteration of food webs, habitat degradation, disruption of fisheries and coastal infrastructure, and risks to human health. Their beneficial effects on biodiversity, ecosystem functions, and services include the creation of novel habitats, trophic support for native species, partial functional compensation for declining native taxa, and substantial contributions to fisheries production and food provision. These effects can co-occur and generate trade-offs. Conservation practice should move beyond rigid origin-based assumptions and explicitly account for the context-dependent impacts of introduced species, particularly in regions where native biodiversity and associated functions are rapidly declining due to ocean warming. Introduced species considerations need to be integrated in conservation planning to meet the goal of protecting 30% of the land, sea, and inland waters (GBF Targets 1 and 3) and to sustain ecosystem services, such as food provision, through fisheries (GBF Targets 10 and 11) amid rapid climate change. Incorporating the positive and negative aspects of introduced species into systematic conservation planning can optimize conservation investments through transparent trade-off analyses. By adopting a pragmatic, holistic approach to conservation that recognizes the varied and dynamic roles of introduced species, decision makers can more effectively achieve the GBF conservation and sustainability targets in the eastern Mediterranean.