This app helps to identify and record blue-green algae which naturally occur in lakes, ponds, canals, rivers and reservoirs around the world. These can produce toxins that are harmful to the health of people and animals. These algae are most commonly seen during the summer months, particularly in calm warm conditions.

The app also asks you for details of what activities you are carrying out in or around the water, as blue-green algal blooms pose a greater risk to water-based activities, such as swimming or windsurfing, compared to non-contact activities such as walking. By gathering details of activities undertaken we hope to gain a better understanding of how algal blooms are impacting recreational use of freshwaters in the UK.