Seaweed from the Big Seaweed Search at Wembury 2016 Anna Starley

Big Seaweed Search

2 minute read

Our coasts are home to an amazing array of seaweeds, which can tell us vital information about our climate. Get involved in the Big Seaweed Search to help monitor the impacts of climate change on our marine environment and the unique species that live there

Big Seaweed Search Week

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The Big Seaweed Search is a community science project that we run in partnership with the Natural History Museum.

Through it, we want to learn more about some of the key seaweed species found in our waters, record where they are and find out how their distribution is changing over time. You can help us collect this vital information.

Thong weed seaweed isle of Coll Scotland Mark Kirkland

Credit: Mark Kirkland

Why is seaweed important?

Seaweeds play a major role in marine ecosystems and are a vital part in the marine food chain providing nutrients and energy for other animals.

Importantly, they also help mitigate the effects of climate change and store blue carbon.

As climate change is affecting our marine environment, we're seeing an increase in sea temperature, rising sea level, and ocean acidification. These changes alter the distribution of different seaweed species.

Through the Big Seaweed Search survey, we're recording the distribution of specific species to help us measure the impact of environmental changes.

Know your dabberlocks from your bladder wrack?

Some of the most common and best known seaweeds are the brown seaweeds bladder wrack, with distinctive air-filled bladders, and spiral wrack, which often has a spiral twist. Also common and easily identified is kelp, which forms thick strands of leathery brown leaves. Kelps are cold water species found all around the UK (and in many other parts of the world), though in particularly large quantities around the coast of Scotland.

There are over 650 species of seaweed around the UK. But we just need you to help us map the distribution of 14 of them. Your survey data will help us learn more about how these seaweeds are important in preserving the health and diversity of our ocean.

Shallow waters in summertime in the Hebrides on the West coast of Scotland Joost Van Uffelen

Credit: Joost Van Uffelen via Shutterstock

How to get involved

It’s easy to take part. The Big Seaweed Search guide explains what you need to do, and provides photos to help you to identify each of the seaweeds we are focussing on. You can complete the simple survey on a mobile, tablet or computer.

The survey can be carried out at any time of year and as an individual or in groups – it's up to you.

To get involved simply:

  1. Register to take part and download your guide and recording form at
  2. Choose your 5m of coastline to survey
  3. Fill in your survey form
  4. Take LOTS of clear, close-up photographs for your survey to be accepted
  5. Submit your survey through

See the many ways to take action and get involved

What you can do