Blake Schaeffer

Water, whether in the coastal ocean, or inland lakes and reservoirs, is a vital resource for human activities, and an important ecosystem.

Water resources and habitats can be threatened by poor water quality, as a result of human-induced or naturally occurring phenomena, such as harmful algal blooms.

Cyanobacteria are one type of bloom-forming species that has been linked with significant socio-economic and environmental impacts in aquatic environments.

Of particular concern, is the potential of these blooms to cause respiratory and skin irritation in both humans and animals. Monitoring water quality and providing advisories on these threats, is a challenge for local authorities around the world, in terms of cost and scope of monitoring, and access to suitable supporting data for decision making.

To address some of these challenges the United States Environmental Protection Agency (US EPA) has recently released a mobile app — Cyanobacteria Assessment Network Mobile Application (CyAN app). The app allowsinterested stakeholders to access the latest satellite derived and other information on the presence of cyanobacterial blooms in more than 2,000 lakes and reservoirs, as well as coastal regions, across America (Figure 1).

The main source of satellite data for this service are the OLCI sensors aboard the Sentinel-3 satellites — part of the European Commission Copernicus programme, and operated by EUMETSAT.

The combination of relatively high spatial and temporal resolution, along with suitable spectral resolution and sensitivity for water remote sensing, makes the OLCI data a good candidate for water quality monitoring schemes.

The app was tested for over a year, and during 2017 its use was validated with the issue of 25 health advisory notices.

Users report that the app allows them to better manage limited budgets for field sampling and the app and imagery within it make communication with other stakeholders much simpler.

Note: The app is available for international users (for Android only), although the data is only for the US.