LTLS Freshwater Ecosystems ("LTLS-FE"): Analysis and future scenarios of Long-Term and Large-Scale freshwater quality and impacts

Lead Research Organisation: British Geological Survey


Long Term Large Scale - Freshwater Ecosystems (LTLS-FE):

UK freshwaters have historically and are currently subject to many chemical pressures on their quality and consequent biological condition. While some pressures (e.g. metals, acidification, oxygen-consuming substances) appear to have eased over recent decades, others (e.g. industrial and personal organic micropollutants, nitrogen and phosphorus) remain and may be increasing.

Whether these contemporary improvements in UK freshwater quality and biodiversity will continue into the future is of great interest to the public who rely on freshwaters for recreation, to water companies for drinking water supply, to industry and to the statutory regulators - and there is recent evidence that some recent improvements to biodiversity may have stalled. The impact of projected future climate on UK freshwater quantity has been recently quantified, but few studies have comprehensively explored how UK freshwater quality processes, pollutant interactions and biodiversity, might be impacted by a warmer climate and catchment changes.

Exploring how water quality at the UK scale may change in the future requires an understanding of its numerous, spatially variable drivers and how they interact over time, and a model that can put all this information together. In this project, called "Long Term Large Scale - Freshwater Ecosystems" or "LTLS-FE", our objective is to use a dynamic model of the UK landscape to simulate the health and quality of our freshwaters from the present day into the future. However, the future is highly uncertain, so we have to consider a number of possibilities, or "scenarios". These scenarios will be used as input to our model (LTLS-Freshwater Model) and will allow us to quantify the responses of rivers and lakes to projected future climates and associated scenarios of polluting chemicals and pathogens (collectively referred to as "pollutants") and their likely impacts on freshwater biodiversity.

To link the national-scale water quality model with a freshwater biodiversity model we will first use available UK freshwater data for diatoms, macrophytes, macroinvertebrates and fish to develop an understanding of how riverine ecosystems are affected by multiple stressors such as nutrients, hydrology, morphology, temperature and toxins. A second approach using statistical models will allow us to investigate the extent to which ecological traits account for stressor responses. Models will be used to extrapolate ecological responses to stressors in space and under the different scenarios up to 2080.

The hydrological and ecological modelling of multiple scenarios up to 2080 will result in future scenarios of pollutants and ecological responses for every UK river (on a 5km grid) across the UK. These scenarios will be discussed with stakeholders and the project team to identify the best way to present them. Options include analyses showing how particular regions or rivers can mitigate against freshwater risks, and/or analyses to help identify which of the many changes, or combination of changes in each catchment has the greatest impact on downstream freshwater quality and biota.

To maximise the uptake of the outputs from the project we will engage with stakeholders to better understand the models and datasets that are of extended use to them. Following on from this, all model code developed in the project will be open source and available in a public repository (github), and datasets will be made available in the publicly available NERC Environmental Information Data Centre (EIDC). For those stakeholders who may not wish to download model code and datasets, a more-visual alternative will be provided in the form of a map-based web-tool to show how water quality and biodiversity in UK rivers might change in the coming decades.


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