Kelp in shallow waters, with sunlight streaming from above © Joost van Uffelen / Shutterstock

Big Seaweed Search

At a glance

Photograph and identify seaweeds on the UK's beautiful coasts

Type of activity: Outdoors

Who can take part? Everyone

When? All year round

Where? UK seashore

How long will it take? About one hour

Join us to monitor the effects of environmental change on Britain's sealife by exploring the seashore and recording the seaweeds that you find there.

Since 2009, hundreds of people have taken part in the Big Seaweed Search. Alongside other research, the data you've gathered shows that the distribution of seaweeds around the UK is changing.

How to take part

Step 1. Select your survey area. Choose a five-metre-wide plot that runs from the top of the shore down to the sea. You can mark your survey area with a bucket, sticks or using natural landmarks.

Step 2. Take a picture of your plot. Stand with your back to the sea and take a picture of your survey area. This gives our scientists a good idea of the conditions on the shore where you carried out your survey.

Step 3. Get seaweed spotting. Walking away from the sea, carefully explore the whole of your plot for about one hour. Take photos of your finds. You only need to record the 14 species that are listed in the guide.

Step 4. Submit your results. Tell us what you found and upload your photos using our online form. A seaweed expert will confirm your identifications using the pictures you have uploaded.

You can repeat the survey throughout the year.

Want to take part?

Take a look at the Big Seaweed Search guide, which has full instructions and a recording form.

Resources to help you take part

Downloadable guides and forms

Visit our Dive into the details page for all resources including the guide for group leaders and Welsh language versions.

Online identification help

Our project partners at the Marine Conservation Society have a page to help you identify the 14 types of seaweed we are investigating. Meet the seaweed types.

Contact us

Any questions? Please contact us by emailing: communityscience@nhm.ac.uk and put 'Big Seaweed Search' in your subject heading.

Submitting your survey

You can submit your results and photos using our online form.

Dive into the details

Uncover why the Big Seaweed Search matters and stay updated on its progress. Find out how your contributions are shaping marine research and download additional resources.