The Danube Delta is the second largest river delta in Europe. It spans across ten different countries, with Romania possessing the largest part of it. The Danube Delta serves as an important hub for biodiversity that also filters nutrients and pollutants before reaching the Black Sea. However, climate change and increasing pollutants in the river lead to an alarming rise in eutrophication. Eutrophication occurs when there is an overabundance of nutrients in water, which causes excessive algae blooming and oxygen depletion. This leads to the demise of fish and other aquatic species, resulting in ecological imbalances. Given the river’s significance for clean water and food sources for living organisms, eutrophication possesses an alarming threat to ecosystem survival, with potential future economic burdens for remediation.
In summer 2023, we explored the Danube Delta in Tulcea, Romania, to investigate the varying nutrient levels across select lake complexes. Our findings revealed differing high levels of chemical species—ammonium, nitrate, nitrite, and phosphate in each lake complex. These levels offer insights into water health and could be explained not only by anthropogenic causes, but also by natural factors in that complex. This research will elaborate on how these chemical variations result from both anthropogenic and natural factors, emphasizing the need to distinguish them for effective nutrient control measures. Given the dynamic nature of water bodies, ongoing monitoring is essential for maintaining water quality, addressing climate change impacts, and fostering international cooperation. Neglecting this surveillance could lead to irreversible long-term environmental consequences.