Big Seaweed Search - Dive into the details

On this page you'll find out why your survey is important, what we've find out, and a whole list of downloadable resources.

If you would like to take part, go to the main Big Seaweed Search page.

Why your survey is important

Home to a particularly high diversity, the UK is a special place for seaweeds, with over 650 species.

Understanding more about them is critical to protecting marine environments. Seaweed creates habitat where fish, invertebrates, birds, and marine mammals find food and shelter.

We know comparatively little about the abundance and distribution of seaweed species. So it is important to record them and monitor how they change over time.

Your observations will give us a better picture of how seaweeds are affected by:

• rising sea temperature
• the arrival and spread of non-native species of seaweed
• ocean acidification (the sea becoming more acidic as a result of absorbing carbon dioxide from the air)

The Big Seaweed Search has already had big impacts scientifically, with data feeding into the UK Red List for seaweed species of conservation concern.

Project updates

If you want to know what kind of data is being collected and the best ways to contribute more, please read our updates.

Project reports

If you want to know what kind of data is being collected and the best ways to contribute more, please read our updates:

Seaweed science

In 2022, our seaweed scientists released a scientific paper evaluating the citizen science project and four years of seaweed data, to highlight any findings and areas of development for the project. Find out more and read the full paper here.

Downloadable resources

• Big Seaweed Search guide PDF (3.5MB)
• Recording form PDF (0.6MB)
• For group leaders: Guide for group leaders PDF (4.9MB)

Dual Welsh/English language resources

• Big Seaweed Search guide Welsh/English PDF (5.8MB)

Tips and guidance

• 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.
• Download our tips on taking your survey photos PDF (3.1MB)

Staying safe on the seashore

• Take a friend and a mobile phone so you can call for help if you need to.
• Rocky shores have many trip hazards and can be slippery. Wear sturdy footwear and walk slowly.
• Don’t survey in bad weather. Stormy or windy weather can make the seashore dangerous.
• Dress for the weather. You might need a raincoat or sunscreen.
• Make sure you wash your hands after touching the seaweeds.

Frequently asked questions

When should I do the survey?

You can do the survey at any time of the year.

Try to start your survey an hour before low tide. This time is best for your safety and for seaweed spotting, too. You can check tide times for your chosen beach at www.tidetimes.co.uk.

How should I select my survey area?

Select a five-metre-wide plot (about five adult paces) 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.

Should I record all seaweeds I find?

You don’t need to record any species you find that aren’t listed in the guide. If you aren’t sure, check their identifying features.

Only record species if they are attached to rocks or other hard surfaces. Ignore any seaweed washed up on the beach too, as it may have come from another place.

Keep up to date with the project

Don’t miss out on the latest findings. Join the Community Science mailing list to find out about the survey's discoveries.

Marine Conservation Society newsletter

If you'd like to hear more about other projects and work the Marine Conservation Society is involved in, you can sign up to their newsletter on their website.

Related pages