THE ECOLOGICAL CRISIS IN THE DANUBE DELTA: CAUSES, CONSEQUENCES AND MANAGEMENT RESPONSES

ANALYTICAL NOTE

(Institute for Danube Research, September 2025)

Abstract.
This article analyses the current ecological crisis in the Danube Delta, which unfolded in 2024–2025 as a result of prolonged drought and a dramatic decrease of the river discharge to historical minimums. The role of climate change and anthropogenic interventions (notably dredging works on the Chilia and Bystroe branches) is highlighted. Ecological, socio-economic, and transboundary consequences are examined. Special attention is paid to the lessons of the “Bystroe case” (2003–2006) and the need for ecological reconstruction of the Razelm–Sinoe lagoon system. Policy recommendations are proposed, focusing on scientific monitoring, transboundary cooperation, and social support for local communities.

Introduction

The Danube Delta is the largest wetland ecosystem in Europe and a UNESCO Biosphere Reserve of global significance. Covering approximately 4,178 km² (82% in Romania, the rest in Ukraine), it represents a unique hydrological, ecological, and socio-economic complex.

In 2024–2025, the Delta faced the most severe crisis of the last two decades. In August 2025, the river discharge fell to 2,150 m³/s (half of the multiannual average for August and only one-third of the long-term mean of ~6,400 m³/s). This decline triggered widespread drying of channels, lakes, and lagoons, biodiversity loss, and disruption of local livelihoods.

Problem Statement

The crisis is shaped by a combination of factors:

-       Climate change: prolonged drought and reduced water inflows.

-       Anthropogenic activities: dredging works on the Chilia and Bystroe branches, altering the distribution of water flows.

-       Institutional weakness: inadequate crisis response by the Danube Delta Biosphere Reserve Authority (ARBDD) and insufficient transboundary coordination between Romania, Ukraine, and the EU.

Literature Review

Research on the Delta has addressed both ecological and governance challenges. Sahanenko (2018, 2022) emphasized systemic risks to environmental security and the need for integrated resource management. Romanian scholars (Munteanu, 2005; Gheorghe, 2019) highlighted the hydrological risks of dredging. International frameworks such as the ICPDR reports and the EU Danube Strategy (EUSDR) stress the importance of joint monitoring and governance.

Findings

Hydrological Dimension

The river discharge in 2025 reached historical lows (2,150 m³/s), leading to a 60% reduction in water levels in some lagoons (Razelm, Sinoe, Chamurlia, Zmeica).

Ecological Impacts

-       Fish populations concentrated in remnant pools, making them vulnerable.

-       Migratory birds lost feeding grounds.

-       Vegetation adapted to seasonal flooding degraded due to desiccation.

Anthropogenic Factor: Bystroe Canal

The dredging of the Chilia and Bystroe branches redirected significant flows, reducing water availability for the Sulina and Sfântu Gheorghe branches in Romania.

Socio-economic Consequences

-       Collapse of traditional fisheries.

-       Sharp decline in tourism.

-       Loss of income and growing social tension in local communities.

Lessons from the “Bystroe Case”

The 2003–2006 dispute showed that dredging without ecological assessment provokes severe international conflicts. Despite the suspension of the project at that time, renewed works in 2023 revived old tensions and risks.

Recommendations

1.    Ecological reconstruction of the Razelm–Sinoe system through reconnection with the Black Sea.

2.    Establishment of a joint Romanian–Ukrainian scientific monitoring platform.

3.    Strengthening transboundary mechanisms under EUSDR and ICPDR.

4.    Social adaptation programmes for local communities.

5.    Transparency of ARBDD and regular publication of monitoring data.

Conclusion

The crisis in the Danube Delta is systemic, resulting from climate stress, anthropogenic interventions, and institutional weaknesses. Without urgent transboundary measures, the Delta risks irreversible ecological degradation and the loss of its UNESCO Biosphere status.

 

References

1. Sahanenko S. Environmental Security and Resource Management in the Global Context. Kyiv: NADU, 2018.
2. Sahanenko S. Transboundary Cooperation in Environmental Policy. Lviv: LNU, 2022.
3. Munteanu V. The Danube Delta: Management Challenges in the Context of Environmental Change. Bucharest: Romanian Academy Press, 2005.
4. Gheorghe A. Hydrological Risks in the Danube Delta. Constanța: Ovidius University Publishing, 2019.
5. ICPDR. Annual Report on the Danube River Basin. Vienna, 2023.
6. European Commission. EU Strategy for the Danube Region (EUSDR). Brussels, 2024.