Freshwater Umbrella Presentations

The UK Freshwater Umbrella research programme — poster presentation

Freshwater Umbrella posterAbstract

Freshwater bodies in the uplands are subject to often excessive levels of atmospheric inputs, such as sulphur, nitrogen, heavy metals and POPs. These pollutants can have adverse effects on the ecological status of the water body. Reducing these adverse effects continues to be a major driver of air quality policy in the UK and internationally. In addition, there are specific conservation objectives for designated freshwater bodies, and a requirement in the EC Water Framework Directive (WFD) for all freshwaters to achieve good ecological status by 2016.

Atmospheric deposition of sulphur has led to the acidification of many freshwater sites in sensitive upland regions of the UK, with damaging consequences for aquatic ecosystems. International agreements under the UNECE Convention on Long Range Transboundary Air Pollution (LRTAP) and EC Directives, have led to substantial reductions in sulphur dioxide emissions over the past thirty years, and upland waters are now starting to show a decline in in sulphate concentrations. The UNECE Gothenburg Protocol and the EC National Emission Ceilings Directive (NECD) both contain commitments to further reduce emissions of acidic and nitrogen-containing air pollutants, from 2024.

The UK Freshwater Umbrella science programme is a series of three-year research projects commissioned by the Department for Environment, Food and Rural Affairs (DEFRA; previously the Department of Environment and Department for Environment, Transport and the Regions) and the UK devolved agencies to investigate aspects of air pollution and their effects on freshwater environments. The science programme is designed to underpin policy decisions and to inform decision makers of the relevant scientific background for their deliberations. The members of the Freshwater Umbrella also act as advisors to DEFRA and the devolved agencies on matters concerning air pollution effects and freshwater ecosystems.

Deposition of nitrogen-containing pollutants (nitrogen oxides and ammonia) can contribute to acidification through leaching of nitrate from soils. Despite reductions in nitrogen oxides emissions of 40% and in ammonia emissions of 15% in the UK since 1990, monitoring data show that levels of nitrate in UK freshwaters are not in decline. Similarily, concentrations of nitrate in rain so far show no statistically significant downward trend. The reasons for these observations need further investigation.

The main focus of the current Freshwater Umbrella research programme is the role of nitrogen and its effects on freshwater ecosystems both as a eutrophier and through the leaching of nitrate from catchment soils.

An overview of the past work of the Freshwater Umbrella and a description of the current research programme on nitrogen effects in UK upland freshwaters will be presented.


Gavin L. Simpson & Chris Curtis

Publication Date:

June 2005


Adobe pdf icon Freshwater Umbrella poster presentation (2.2 MB | PDF)