Blue-grey worm

Take part

Discover the health of your local pond and help scientists with valuable research

Creatures living in the pond can provide clues to how healthy the water is

Take part in the OPAL water survey and discover what animals living in the water can tell us about its quality. It's fun, you'll learn new skills and your results will help scientists learn more about the health of lakes and ponds across the country.

What you need to get started

All the instructions and guides you need can be downloaded below. You'll also require a few household items (listed in the field guide) and if possible some pH strips (available from most garden centres).

Some of you will have received one of our survey packs. These contain all the necessary downloads and pH strips, so there is no need for you to download the items below.

We strongly recommend that you print all documents in colour.


Please show care and respect to our environment.

Ponds and lakes are home to many important creatures.

A good biosecurity routine is also essential to minimise the risk of spreading invasive species.

Find out more about biosecurity

Need some pH strips?
Email your address and the number you require to opal [at] imperial [dot] ac [dot] uk

Finding a pond

Before you start your survey, you'll need to choose a suitable pond or lake. You may already have somewhere in mind but if not, we've prepared a guide on the many tools you can use to find somewhere suitable near you.


Downloads - what you need to take part

Workbook (PDF, 1MB) - Background information and recording sheet


Field guide (PDF, 1.8MB) - Full instructions and invertebrate guide


OPALometer (PDF, 172KB) - A printable OPALometer





Alternatively, download the whole survey pack as one zip file

Complete water survey pack (ZIP, 3.7MB) - All the instructions, guides and downloads above in one zip file


You may download these documents for use in the context of the OPAL project only. All other rights are reserved.


Group leader and safety information

Group leaders may benefit from our support pack with information and ideas on planning a group event, and additional safety information from the Royal Society for the Protection of Accidents (RoSPA).