Climate change and the adaptation of local communities thereto are at the center of the international research project Iason+, led by Romania's Danube Delta National Research and Development Institute (INCDDD). Russia's war in Ukraine has added new pressures, forcing Black Sea-region specialists to respond to increasingly complex ecological situations.

The original Iason project, launched before the escalation of the conflict, focused on monitoring invasive alien species under climate-change conditions. In the Romanian - Ukrainian Danube Delta Biosphere Reserve, researchers study five species: the Amur goby, the false indigo-bush (Amorpha fruticosa), the Colorado potato beetle, the pheasant, and the golden jackal.

Project manager and biologist Gabriel Lupu says some species fall into ambiguous conservation categories: 'The pheasant we study has an uncertain status. At European level it is on the IUCN Red List, but in Romania it is an invasive species with clear effects on native fauna. We don't know whether to protect it or control it - it sits right on the boundary. The jackal is in the same situation.'

Under Iason, researchers created an open database for invasive species. The follow-up project Iason+ (launched in 2023) continues this work and adds a new dimension: analyzing how invasive species affect ecosystem services.

'We study the ecosystem services provided by delta areas and how invasive species influence them. This goes directly to community well-being. The Danube Delta is the most populated delta in the Black Sea basin, which helps our research. Some effects can even be positive - for example, honey from Amorpha fruticosa,' Lupu said.

Lupu notes that climate change is already altering species behavior and distribution: 'Climate change shifts the range limits of species. The Amur goby, for example, seems to have reached the Delta naturally and is spreading westward, moving up the Danube. That means it will appear in Romania's inland rivers. Any climatic shift creates good conditions for species that were not there, and worse conditions for those that already were.'

The researcher also approached war-related ecological disruptions, stating that the Ukraine war is another major challenge: 'Explosions and loud blasts push mobile fauna to migrate. We've seen dolphins leaving the Ukrainian coast and moving south to Romania and Bulgaria. Higher numbers mean higher observed mortality, not necessarily disease. Flamingos in the Delta also arrived after being displaced from southern Ukraine.'

Research and traditional fishing on the Chilia branch are also affected, with stricter permits and drone-use restrictions, while Ukrainian partners work under wartime conditions.

Lupu says local authorities, NGOs and communities are receptive to using invasive species as a management tool: 'It may seem unusual, but communities are open, especially because ecosystem services matter to them. Using what the environment provides can support local development - and the best way to control invasive species is often to use them.'

Looking at the broader implications for the Delta, Lupu warned that climate extremes, water scarcity and depopulation are already reshaping the Delta: 'Desertification is gaining ground in Romania too. The Delta is the driest region in the country, despite having the most water. When people no longer have access to drinking water and remain isolated, they must find alternatives. Depopulation is obvious: young people leave, the population ages and shrinks. Research helps us understand whether humans can continue living there or not - what happens to fish, water, biodiversity. Iason+ just brings together data from all deltas studied in the project.'

The Iason+ project runs until the end of this year, with partners from Georgia, Greece, Romania, Turkey and Ukraine, a budget of €1.3 million, and support from the Interreg VI-B NEXT Black Sea Basin Program, co-funded by the European Union. The program serves as a platform where ties between participating countries are strengthened, new ones are created, and regional actors come together to contribute to the sustainable management of resources for the benefit of local communities. AGERPRES (RO - writing by: Luisiana Bigea; EN - writing by: Simona Klodnischi)