Beach life

Updated Thursday 12th October 2006

Discover the easy way to explore the rich variety of beach life

Starfish Copyrighted image Icon Copyright: BBC

A sandy beach is the ideal spot for relaxing in the sun, sipping a cold drink and reading a book.

There are seagulls about, but otherwise it looks like a beautiful but lifeless habitat. Yet look for clues on the surface at low tide and you may find some interesting fellows hiding in wet sand, where they are protected from drying out.

On some beaches you find large worm casts, each about six to ten centimetres from a small circular depression in the sand. The worm cast marks the rear end of a lugworm in its U-shaped burrow, and the depression marks where the head is eating sand.

Collect some sand from this area, digging to about 30 cm depth; now collect another sand sample from an area without lugworms. Put each sand sample into a tall plastic water bottle and add seawater; shake each bottle, then allow the sand to settle.

You should see layers of sediments arranged according to particle size; the largest sand particles are on the bottom, and light organic matter is at the top. Compare the layers in your 2 bottles. Which bottle contains the most organic matter? Suggest why lugworms are common in one part of the beach, but not in another.

Lugworms on a beach Copyrighted image Icon Copyright: Flickr CreativeCommons evilnick http://www.flickr.com/photos/32655742@N00/83796942/ Lugworms on a beach [Image: evilnick - CC-BY-NC-ND licence]

Molluscs such as cockles, tellin and razor shells hide in wet sand; dig in the sand to look for them, or collect their empty shells.

Higher up the beach on the strand line, there is dead seaweed, driftwood and litter. Disturb the seaweed and sand and you may see jumping sandhoppers - small shrimp-like crustaceans that eat rotting seaweed.

Animals in the sand are part of the food web of a sandy shore. Birds, turnstones, rock pipits and sandpipers hunt for sandhoppers on the strand line.

Look for clues that indicate which predators ate the inhabitants of your seashells.

Small round holes in tellin shells were bored by necklace shells - predatory snails that scrape out and eat tellin alive. Cockleshells with large jagged-edged holes were smashed by the stout beaks of oystercatchers. So a sandy beach is not always a lifeless habitat; on the contrary there may be a varied community of animals there, providing food for fish, sea birds, and humans.

Lugworms digest rotting organic matter from dead animals and seaweed, which is mixed with sand and mud. They cannot feed in ‘clean’ sand.

This article was originally published Summer 2005 as part of the Coast postcards pack

 

For further information, take a look at our frequently asked questions which may give you the support you need.

Have a question?

Other content you may like

Beachbrains Creative commons image Icon The Open University under Creative Commons BY-NC-SA 4.0 license article icon

Science, Maths & Technology 

Beachbrains

Ever tried to picture how many neurons we have inside our brain but can't envisage it? Use this busy beach analogy to help you understand the brain: 

Article
article icon

Science, Maths & Technology 

Article
Rough Science 3 New Zealand: Kathy Sykes' Diary: Treasure Hunt Copyrighted image Icon Copyright: Production team article icon

TV, Radio & Events 

Rough Science 3 New Zealand: Kathy Sykes' Diary: Treasure Hunt

Kathy Sykes's diary about the challenge for the Treasure Hunt programme, from the BBC/OU series Rough Science 3

Article
String of sausages lichen Copyrighted image Icon Copyright: BBC audio icon

Nature & Environment 

String of sausages lichen

Could this unusually named lichen be making a comeback?

Audio
10 mins
Monitoring polecat populations using roadkill Creative commons image Icon 'Velvet' / Peter Trimming / CC BY 2.0 under Creative-Commons license article icon

Nature & Environment 

Monitoring polecat populations using roadkill

Are polecat populations growing? One way to check is to survey numbers of polecats live and dead on the roads

Article
How Do We Listen In? Copyrighted image Icon Copyright: Used with permission article icon

Nature & Environment 

How Do We Listen In?

How do we monitor the communication we cannot hear? Learn more about infrasound monitoring

Article
Island life Copyrighted image Icon Copyright: Thomas Langlands | Dreamstime.com audio icon

Nature & Environment 

Island life

The Saving Species team join Malcolm Ogilvie on the island of Islay off the west coast of Scotland to discuss his career as a British ornithologist, and his area of expertise - wildfowl

Audio
30 mins
Dancing in the Spring: Purple emperor butterfly Copyrighted image Icon Copyright: Thinkstock audio icon

Nature & Environment 

Dancing in the Spring: Purple emperor butterfly

From an ancient woodland in Wiltshire, conservation advisor for the National Trust, Matthew Oates, talks to the Saving Species team in an extended interview, and opens the door to the hidden world of the purple emperor butterfly.

Audio
15 mins
Life on the Beach Creative commons image Icon markkilner under CC-BY-NC-SA licence under Creative-Commons license article icon

Nature & Environment 

Life on the Beach

Patricia Ash introduces the range of life you can find on British beaches

Article