If you go down to the beach today | Big Seaweed Search

This week HLF Identification Trainer of the Future, Anthony Roach, introduces us to the marvellous diversity of seaweeds on Britain’s shores and shows you how you can contribute to citizen science by recording them as part of the Big Seaweed Search.

Seaweeds are incredibly diverse and beautiful organisms. They are strong biological indicators of the health of our environment and play an important role in the marine and coastal environment, despite being perceived by some as drab, slimy, green and brown sludge hanging from the rocks or smelly dried husks that litter the high tide mark. The Museum’s seaweed researchers and staff at the Angela Marmont Centre for UK Biodiversity are therefore encouraging everyone to learn more about seaweeds, to map their diversity and assess how they are responding to climate change through the Big Seaweed Search.

Photo of Anthony stood on rocky shore by the sea, holding a large, long, brown seaweed in two hands.

Anthony Roach searching for seaweeds, holding sugar kelp. © Holly Morgenroth.

I grew up near the coast in Devon and I certainly over-looked seaweeds when whiling away countless hours rock pooling. I would slip and slide my way over seaweed covered rocks in search of the jazzier or more colourful marine stars of the rock pool such as crabs, starfish, sea anemones and blennies. I have discovered however that there is so much more to seaweeds than at first meets the eye.

Photo of red, brown and green seaweeds covering rock.

Seaweeds on the shore at Wembury beach, Devon, including Irish moss (Chondrus crispus). © Anthony Roach.

What are seaweeds?

Seaweeds are at the base of the marine food chain. Like plants on land they photosynthesise, taking in carbon dioxide. Many animals rely on seaweeds for food and shelter. Seaweeds are marine algae which attach themselves to the sea floor or rocky shores by a holdfast which anchors them in place. In some species a stem-like structure (stipe) leads to leaf-like lamina or blades, some of which contain air bladders on the blade to help the seaweed to float.

Photo of white tray of water containing red, green and brown seaweeds.

Red and green seaweeds collected on Lyme Regis beach, displayed to promote the Big Seaweed Search at the Lyme Regis Fossil Festival in May this year

Seaweeds are commonly divided into red, green and brown seaweeds based on their colour, but occur in a bewildering array of shapes and sizes. You may be familiar with some groups, such as the common brown seaweeds (the wracks) found around the UK coasts. There are many different types such as serrated wrack (Fucus serratus) and spiral wrack (Fucus spiralis) that you may have seen.

Another common group that you can regularly find on rocky shores are the kelps such as sugar kelp that I am pictured handling above. You may also be familiar with laver (Porphyra dioica) – a red seaweed collected and processed in Wales since the 17th century to make ‘laver bread’. The red fan-shaped (Chondrus crispus), better known as Irish moss, has also been used a health remedy in Ireland.

The Big Seaweed Search

Changing sea conditions, climate change and the arrival of invasive species such as wireweed  (Sargassum muticum) may be having an impact on the ecology of UK seaweeds and many other marine organisms. To assess this impact, we need your help to track the changing distribution of seaweeds around the UK.

The Museum would like your help to record 12 different types of red, brown and green seaweeds that we have highlighted in the survey to locate on rocky beaches.

Seaweeds out of water often will appear unattractive, however as I discovered when collecting seaweeds during the Lyme Regis Fossil Festival, once in water, some of them are spectacular looking. You may also be surprised by the diversity of seaweeds in your local area!

Not only will you gain an appreciation of seaweeds and the marine life they support, you’ll be contributing to useful data that can be analysed by scientists here at the Museum.

Several species of red, brown and green algae in water.

Kelp growing in a rock pool at Wembury beach, Devon. © Anthony Roach.

Take part: download the ID Guide and recording form

It is fun and easy to take part – simply walk along the beach and tell us:

  • What is the seashore like?
  • Which of the 12 seaweeds you can find, and how much is there of each?
  • How many limpets can you find in 1 minute?

Fill your answers in on the form you can download and send your completed form to us via email or post.

The Museum’s Algal Collections and Seaweeds online

I recently met with Jo Wilbraham, Algae Curator at the Museum, whose job it is to look after one of the largest seaweed collections in the world. The collection numbers nearly a quarter of a million specimens. It is a treasure trove and some specimens are over 300 years old. They chart the changing diversity of seaweeds, as many are now very rare or extinct.

Active research continues to take place on these existing collections, alongside citizen science initiatives like the Big Seaweed Search to gather new data to understand the changing distribution of seaweeds. Some collections have now been digitised so you can view digital images of our historic seaweed collections.

A display of 20 different species of seaweed, presented in a grid of equal sized squares. Seaweeds range in colour from green, yellow, orange and red, to brown.

Seaweeds collected from the island of Jersey in the 1850s and 1860s

As W. H. Davies said in his poem Leisure‘We have no time to stand and stare’. Perhaps if we did, we might gain more respect, awareness and understanding of the value and richness of seaweeds around our shores. We might also further appreciate the Victorian art and science of collecting seaweeds – I’ll introduce you to some key figures in the study of marine life in my next post.

Thank you Anthony!

Anthony Roach is one of five Heritage Lottery Fund Identification Trainers for the Future, at the Angela Marmont Centre for UK Biodiversity.  The programme trains individuals passionate to develop a career in the UK biodiversity sector, in identification, curation and public engagement skills, to address a critical shortage in wildlife identification and recording within the UK. Anthony also works as a Science Educator at the museum.