Sandy Shores

Question 1

Why do finer sand particles settle at the bottom of the shore and larger particles at the top?

Answer 1

When a wave travels up the shore it is carrying both large and small particles in suspension. As it reaches its maximum distance the wave slows allowing the larger particles to settle but not quite enough time for the smaller particles which get taken back down to the bottom of the shore.

Question 2

What properties of sand are affected by grain size and sorting?

Answer 2

• Porosity
• Permeability
• Penetrability
• Organic matter content.

Question 3

What affects beach steepness?

Answer 3

• Grain size
• Waves doesn’t always have the energy to carry larger sand particles back down the beach, the water can drain through the larger particles and travel back to the shore bottom underground
• Wave steepness: the steeper the wave, the flatter the beach because there is more energy to carry particles back.

Question 4

Describe the situations where there would be freshwater on the shore.

Answer 4

• Freshwater streams

- Upwelling from hill runoff.

Question 5

How does sand particle size affect how deep in the sediment that oxidation can take place?

Answer 5

In larger particle sands water can get deep into the sediment to oxidise it, unlike smaller particle sands.

Question 6

What causes strandlines?

Answer 6

Different tide levels.

Question 7

What is the biological importance of strandlines?

Answer 7

• Large amount of biological material which provides habitat for insects
• Birds feed here on insects
• Fragments to form detritus.

Question 8

Describe sand dunes.

Answer 8

Pioneer grasses (marram) colonise the sand dunes stabilising the sand. When it decomposes it converts the sand to soil allowing succession.

Question 9

Give some examples of the environmental gradients of the shore.

Answer 9

• period of inundation
• drying-wind effects
• freshwater influences
• Depth of water table
• Oxygenation
• Sediment particle size
• Organic matter
• Bird or fish predation.

Question 10

What organisms are found on sandy shores?

Answer 10

• Beach fleas/sand hoppers
• Heart urchins
• Molluscs
• Crabs
• Fish e.g. sand goby
• Birds - oyster catcher
• Polychaete worms:
• Lugworm
• Sand mason worm
• Catworms
• Paddle worms.