From climate change impacts in lakes and pollution issues in rivers to measuring greenhouse gas emissions from freshwaters, UKCEH researchers are presenting on a wide range of topics at the 13th Symposium for European Freshwater Sciences. The event brings together the European freshwater community and is hosted this year by the Freshwater Biological Association in Newcastle-upon-Tyne from 18-23 June 2023. See details of UKCEH participation below.

Oral presentations

Monday 19 June


  • Dr Linda May: Climate change impacts on standing waters – the need for urgent action

    We explored potential changes in climate stressors on Scottish lochs to 2080. We found that, between 2015 and 2019, the water temperature of 88 per cent of lochs had already increased by between 0.25°C to 1.0°C per year and by even more in 9 per cent of lochs. Our results suggest that average April to September water temperatures in all Scottish lochs will probably rise by about 3°C by 2080, and that extreme drought events will become more likely, increasing the risk of algal blooms. We provide evidence that climate change risk assessments are needed urgently for all standing waters to inform an evidence-based, whole system approach to the sustainable management of lakes and reservoirs before it is too late.

    This talk is part of session RS13 Climate change and freshwaters: challenges and solutions (10:30-12:00)


  • Professor Andrew Johnson: Using a 30-year macroinvertebrate and chemical record to reveal what has driven the recovery in biodiversity in English rivers

    National macroinvertebrate diversity has steadily improved in England over the past 30 years, but why? As part of the NERC-funded ChemPop project looking at chemical impacts on wildlife populations we matched macroinvertebrate records over 30 years with location, chemical and physical records across England. We used statistical analysis to identify which stressor or stressors can best explain the variability in macroinvertebrate family richness over 30 years in English rivers.  All environments showed improvements, although high upstream urban land use exerted a greater drag than high wastewater exposure or high cropland use in the catchment.

    This talk is part of session SS01 Mechanisms underlying responses to multiple stressors (14:15-15:45)


  • Andrew also chairs session 3G A critical examination of positive changes in river diversity across Europe and links to improving water quality (16:15-18:00)

    Strong evidence exists for increasing national macroinvertebrate and fish diversity (richness) having taken place across English rivers over the past 30 years, where excellent records are available. Similar evidence exists for positive transformations in macroinvertebrate richness in the Netherlands, France, and Switzerland. Why is this improvement so broad and happening at the same time? Why is it happening in rural as well as urban rivers at the same time? Has broad water quality improved, are river habitats getting better, what is going right and why? This session offers an opportunity for participants to debate with us or challenge us on these surprising observations.

Tuesday 20 June

  • Dr Ellie Mackay: Climate change feedbacks - is lake warming impacting internal nutrient cycling?

    Using long-term monitoring data from the Cumbrian Lakes Monitoring Platform from the last seven decades in four lake basins, we explore coherent and lake-specific changes in lake thermal properties, dissolved oxygen concentration and nutrient dynamics. These lakes show a clear and coherent increase in their surface and deep water temperatures and measures of thermal stratification over time. Dissolved oxygen changes and nutrient dynamics are more lake-specific; however in the smaller lakes the increased duration of low oxygen concentrations may be changing the seasonal pattern in nutrient dynamics, with indicators for increased internal loading of nutrients during the summer and autumn seasons.

This talk is part of session RS13 Climate change and freshwaters: challenges and solutions (10:30-12:00)

Friday 23 June

  • Don Monteith: Profound changes in the chemical and physical characteristics of UK upland lakes and streams resulting from acid emission controls

    We summarise observations from over 30 years of monitoring acid-sensitive upland lakes and streams on the UK Upland Waters Monitoring Network as they respond to large reductions in acid deposition.  We report dramatic improvements in water quality that are largely consistent with model predictions and should be sufficient to promote significant biological recovery. However, some of the changes, including a large increase in dissolved organic matter, and associated loss of transparency were not predicted, while affected waters remain enriched with anthropogenic nitrogen and are also warming. Despite reductions in acidity therefore, the aquatic environments of many of these remote waters appear headed for unprecedented states. We consider some potential implications for biodiversity and drinking water quality. 


  • Amy Pickard: Novel insights from a national scale monitoring network for measuring aquatic GHG emissions

    We are establishing a national measurement network for monitoring aquatic GHGs through the GHG Aqua project. As part of our measurement network we have deployed the UK's first three eddy covariance flux towers to measure carbon dioxide and methane emissions from freshwaters. Our initial data show considerable variability in emissions of greenhouse gases from water bodies between day and night and across seasons.

Both these talks are part of session RS02 Biogeochemical processes and greenhouse gas emissions in inland waters (10:15-12:00)