Freshwaters are losing species faster than any other ecosystem on Earth, and the nutrients pouring into them from farms and cities are a major reason why. Current science has focused almost entirely on simple inorganic nutrients like nitrogen and phosphorus, largely ignoring the complex soup of dissolved organic matter (DOM) that also feeds aquatic life. This matters because researchers have been working with an incomplete picture—they know how single species respond to a few nutrients in lab tanks, but not how whole stream ecosystems respond to the full range of organic compounds under real-world conditions. The team will combine molecular analysis, stable isotope tracking, and environmental genomics in field experiments to map how different organisms shift their behaviour and genetics when exposed to DOM alongside climate change. If successful, this will rewrite the fundamental theory of nutrient cycling in streams, giving water managers a more accurate tool for predicting how rivers will respond to fertiliser runoff and warming temperatures. This is primarily fundamental science, but deeper understanding of how organic nutrients drive biodiversity loss could eventually improve catchment management and drinking water treatment.
View original technical description
Freshwaters are losing biodiversity at a higher rate than any other planetary domain. A wide range of stressors are driving this trend, of which climate change and increasing nutrient delivery from food production and consumption are ubiquitous. Research to date on nutrient enrichment impacts on freshwater biota has been limited by the physical challenge of experimentation in a rapidly changing environment, and a narrow perception of bioavailable nutrient forms. It has focused on species-specific responses to inorganic nutrient forms, often in vitro or in lakes, rarely for flowing waters under ambient conditions, and usually for microbial or planktonic organisms, ignoring the responses of other biotic groups, community level responses to enrichment, and the combined impacts of the range of bioavailable organic compounds in freshwaters. Transformational research is needed to update current nutrient cycling theory for stream ecosystems, shifting from research explaining how part of the ecosystem responds to a limited range of stressors, to fundamental, holistic theory explaining how whole ecosystems respond to a broad palette of stressors. I will lead a multidisciplinary team to tackle this challenge, applying innovative techniques in molecular scale analysis, stable isotope probing and environmental genomics, under field and climatically-altered conditions. We will then use new data-driven modelling to understand relationships between taxonomic and functional shifts in response to dissolved organic matter (DOM) and inorganic nutrient exposure, revealing environment x gene interactions in biotic responses to nutrient and climate stressors. This will advance current theory and transform our understanding of the impacts of the full nutrient portfolio on freshwater ecosystems, revealing the specific role of DOM as this varies according to the composition of the DOM pool, species composition of the ecosystem, stream stoichoimetry and environmental character.
Plain English summaries and category classifications on this site are generated by AI and may not perfectly reflect the original research.
Is something wrong? Let us know