Delivering resilience to climate impacts on UK freshwater quality: towards national-scale cyanobacterial bloom monitoring and forecasting

The summer drought and heatwave in 2018 highlighted the vulnerability of UK water resources to current and future climate change. This vulnerability was not only due to insufficient water quantity, but was exacerbated by water quality issues caused by harmful blooms of blue-green algae (also known as cyanobacteria) that flourished due to the high temperatures and low flushing, particularly in lakes and reservoirs. This had major impacts across the whole of the UK, including higher water treatment costs in many reservoirs, restrictions on drinking water supplies in some regions, closure of many recreational waters, fish kills and the deaths of several pet dogs. Monitoring of blue-green algae in the UK is currently very reactive and limited in scope to <1% of the UK's lakes and reservoirs. This limited monitoring hinders effective management and raises the risks posed to public and animal health. However, recent innovations in the use of data from satellites observing the Earth from space and the use of data collected by members of the UK public using the smartphone app Bloomin'Algae have the potential to change this dramatically by increasing both the number of waterbodies monitored and the frequency at which they are observed. These innovations in earth observation and citizen science have real potential to provide water companies, environmental regulators, local authorities and the public with the data and information they need to better manage the risks posed by toxic blooms of algae.

In this proof-of-concept study we will demonstrate the power of new satellite data, including those from hundreds of small 'nanosatellites' recently launched into space, for monitoring algal blooms in waterbodies across the UK. We will augment this with shore-based citizen observations made by members of the public and relevant agency and industry staff. We will investigate the combined power of these two novel sources of data to identify the presence of bloom events that exceed current UK and World Health Organisation guidelines for drinking water supply and recreational activities. We will also review the potential of the data to improve our scientific understanding of the impact of short-term climate extremes on UK water quality. The two approaches provide complementarity in the spatial scales of sites that can be monitored and allow us to verify findings independently. In parallel, we will assemble a team of scientists with diverse expertise in the use of satellite data, citizen science, modelling and statistics to work in collaboration with water utility companies, the UK health and environment protection agencies, and local authority representatives. This working group will establish a blueprint for a nation-wide bloom monitoring and forecasting service that could feed into and augment a number of their existing systems for monitoring and reporting environmental incidents that have health, social or economic impact. This could include a system that provides direct notifications to members of the public and interested bodies, such as watersport centres, fisheries and vet practices. Such a climate service would greatly strengthen the resilience of the UK water industry, environment agencies, public health bodies and local authorities to future climate change.

The highly applied, proof-of-concept research proposed here is a small but critical first step towards the development of an operational service for the early-warning monitoring and forecasting of harmful blooms of cyanobacteria in UK freshwaters. It is anticipated that the proposed service would deliver significant economic and social impacts to non-academic beneficiaries in the public and private sectors as well as to wider society. These include:
(a) Water utilities. Harmful cyanobacterial blooms are a major issue in many drinking water reservoirs across the UK and these blooms impose significant costs on water utility companies through increased water treatment and restrictions on the consumption of water from affected reservoirs. The development of a service providing timely warnings of blooms in drinking waters would be highly advantageous for water utility companies because such information could strongly guide decision-making leading to reduced treatment costs, avoidance of reputational damage and ultimately mitigate potential risks to public health.
(b) UK Environment Agencies. The UK environment agencies have a statutory responsibility to ensure good status of freshwaters in the UK under the EU Water Framework Directive and to prevent exposure and inform the public in the event of a potentially-toxic cyanobacterial bloom occurring in a bathing water under the EU Bathing Water Directive. They also undertake monitoring in response to reports of blooms in other waterbodies. There are insufficient resources to permit regular sampling at all waterbodies at risk of blooms in the UK and, as such, the monitoring currently undertaken by the environment agencies is highly reactionary. The development of a service providing near real-time information on bloom occurrence would provide the agencies with the capability to monitor more waterbodies, at higher frequency and, if needed, follow-up in a more proactive manner than is currently achievable. This would not only help the agencies fulfil their statutory obligations but it would also help minimise the chance of blooms going unreported, lessening the risks to public health.
UK Health Protection Agencies. The health protection agencies, including Public Health England and Health Protection Scotland, have a duty to protect the public in the UK from threats to their health from infectious diseases and environmental hazards. This includes microbiological hazards, such as toxigenic cyanobacteria. The agencies operate surveillance systems designed to collect, collate and analyse environmental health data to inform future interventions to reduce disease burdens. However, current reporting is highly selective and incomplete. The development of a UK-wide service providing up-to-date data on the occurrence of blooms could be incorporated into current incident reporting systems, greatly improving reporting of harmful events of cyanobacteria and thereby contribute to future efforts to minimise the risks to public health.
General Public. Cyanobacterial blooms in waterbodies used for drinking and recreation pose significant risks to the health of the public, pets and livestock. Mitigation of these risks relies on early recognition, reporting and management interventions. Current approaches to monitoring in the UK means that the presence of many blooms often goes unnoticed by the authorities potentially exposing members of the public to unknown health risks. The development of a service providing timely information on the occurrence of blooms would greatly help local authorities in their efforts to protect public health. Moreover, such a service would enable those members of the public most likely to be exposed (e.g. dog walkers, open water swimmers, water sports enthusiasts) to better self-manage the risks to themselves and/or their pets and livestock animals. This could greatly reduce the risks of both acute and chronic exposure to cyanobacteria and associated incidences of disease.