Isotopes to Study Nitrogen Pollution and Eutrophication of Rivers and Lakes
Project Type
Coordinated Research ProjectProject Code
CRP
Approved Date
12/05/2015Project Status
ClosedStart Date
22/02/2016Expected End Date
21/02/2020Completed Date
12/12/2022Participating Countries
CubaDescription
Water quality in thousands of lakes and rivers around the globe is deteriorating due to rising nutrient levels and other chemical pollutants mainly of anthropogenic origin (e.g., agriculture, sewage, industrial discharges, urban areas) causing changes in their ecological structure and function. The excessive nitrogen pollution (nitrate, ammonium) of surface waters has resulted in change of oligotrophic water bodies to eutrophic and sometimes to hypertrophic states. Environmental isotopes are used not only to assess hydrological processes in terms of surface water quantity, but also to address water quality issues, such as nitrogen pollution. This CRP aims to improve the suite of isotopic markers combined with other chemical / biological substances to better define the possible sources and re-cycling of nitrogen pollution in surface water bodies. The CRP aims to deepening the knowledge on the temporal (diel, seasonal) and in-depth variation of nitrogen isotope data, combined with additional substances, as deeper water bodies may sometimes prevent a complete understanding of nitrogen isotope dynamics from surface water collections. Moreover, improving conventional and promoting new methodologies on nitrogen species isotopic characteristics is expected to facilitate access to a more routine and low-cost use of nitrogen and oxygen isotope data of nitrogen species. Overall, the CRP will aim at improving the capability and expertise among participating Member States in the use of environmental isotopes to better assess the impact of nitrogen pollution and eutrophication on surface water resources availability and sustainability.
Objectives
To improve capability and expertise among Member States in the use environmental isotopes to better assess impacts of nitrogen pollution on water resources variability, availability and sustainability.
Specific Objectives
Assess and improve the interpretation of hydrological processes, sources, interactions and pathways in rivers and lakes.
Assess and improve the suite of isotopes and other chemical and/or biological indicators to evaluate the environmental and anthropogenic impact on surface waters in terms of identifying more accurately the multiple sources of nitrogen pollution and eutrophication.
Assess and improve the understanding and interpretation of N-nutrient dynamics, eutrophication and sediment transport in lakes and rivers.
Explore improved analytical methods of N-related isotope parameters in order to facilitate access to isotope data of nitrogen species and build greater confidence in assessments of nitrogen pollution issues of surface waters.
Impact
The project had a significant impact in the participating countries. In 7 countries it was the first time that N-isotopes were ever applied to assess impact of nitrogen pollution on water resources variability, availability and sustainability. New and young researchers have benefited from their involvement in the project (e.g. Malaysia) though Master’s and PhD theses and were introduced on the use of isotope hydrology techniques. The participants were able to publish their findings in conferences and peer-reviewed journals, which is ample evidence of the improved capability and expertise in the use of environmental isotopes to better assess impacts of nitrogen pollution on water resources variability, availability and sustainability, and which is expected to help the stakeholders adopt protective measures and sound remediation approaches. A large dataset of nitrate isotopes was introduced in GNIR database and is available to Member States. Scientifically-wise, the project offered the identification of global patterns related to nitrate isotopes, which were linked to nitrate sources and biogeochemical processes driven by climatic and meteorological factors. For example, the project showed that river waters undergo quality deterioration due to nitrogen contamination originating mainly from organic nitrogen in manure and septic wastes (46%) and less from dissolved organic matter in the soil (28%) and the application of mineral fertilizers (21%). The link between N cycling and climate was documented through a global survey, and is expected to help further investigate climate change impact on nitrogen cycle. The perception of the locals concerning the water scarcity and contamination was examined through a socio-hydrogeological survey, which indicated “Supply clean water to public” as the main objective of water management in Sri Lanka.
Relevance
The scientific and hydrological results of the CRP clearly demonstrated that the recent developments in field (simpler sampling protocols) and laboratory (use of cheaper, easier to use titanium chloride sample preparation and use of laser absorption spectrometers) methods allow the routine use of this tracer to assess nitrate pollution in a variety of hydrological and climatic settings. The CRP has developed SOP for both field and laboratory methods, ready to be transferred to counterparts involved in both CRPs and TC projects.