Coastal sand dunes

When the water goes out the wind blows the sand which causes it to accumulate, making coastal sand dunes.
The main threats of sand dunes are interception of longshore drift due to the construction of jetties, conversion into agricultural land, drinking water abstraction, levelling for industrial development, afforesstation, removal of sand for mineral extraction, Visitor pressure (people walking on them etc) and pollution.

Coral Reefs

Factors affecting Coral Reefs

Climate Change

One factor believed to be the greatest threat to reefs is climate change. When severe weather events increase in frequency, this causes rises in both sea temperatures and sea levels. The problem with water temperatures rising is that coral reefs need to sustain a sea temperature between 73 and 84 degrees F to sustain growth. 

Pollution

Coral reefs are strongly affected by humans and their pollution. Boating and even coming into contact with coral reefs can cause damage to the ecosystem. Discarding rubbish can cause a huge impact on the environment; turtles can sometimes mistake plastic shopping bags for jellyfish and eat them, causing the creature to starve to death by blocking its digestive tract.

Overfishing and Blast Fishing

Fish might taste delicious but catching too many can be harmful to a coral reef. It can be difficult for a species to sustain life when too many fish are taken from one area. Overfishing of herbivorous fish can also lead to a reef having high levels of algal growth. Another factor affecting coral reefs is blast fishing. This practice involves catching fish by using explosives to blow apart sections of a coral reef.

Disease Outbreaks

Coral reefs are susceptible to disease outbreaks caused by stress, which include the presence of bacteria, fungi and viruses. Some of the diseases found in coral reefs include white-band and black-band disease. White-band disease involves tissue peeling away from coral and the skeleton of the reef being colonized by algae. Black-band disease is caused by bacteria moving along the reef and destroying the tissue.

Location

Coral reefs flourish in shallow areas (less than 120ft, or 37m) in tropical latitudes, or where warm ocean currents flow into more temperate areas. In deeper waters, not enough light penetrates the depths, which means the reef's main food producers, algae and plankton, cannot photosynthesise.

Unfinished questions

Coastal Management at Lyme Regis
1.
a. Clays, sand and muds.
b. Limestone and shale.
c. The old sea wall and groynes offer little protection due to being eroded away.
d. Some of the houses have been damaged due to the movement of the map.
2.
- Its a good tourist location, bringing money to the area.
- Peoples houses are being damaged
- It will pay for itself in tourism.
3.
N/A
4.Hard engineering because its long term and protects houses well. It will cause short term problems though such as lack of access. It will improve visual  quality, which helps tourism.
5.
Lyme Regis could do a reactive response, fixing the land as and when it gets damaged.
6.
N/A
7.

Depositional Features

Depositional features 

In a coastal environment, deposition results in the accumulation of sand and shingle along a coastline. This happens when the swash is stronger then the backswash. Depending on how and where the sediment is deposited, a variety of landforms can be produced.

Spits

A spit is a stretch of sand or shingle extending from the mainland out to sea. They develop where there is a sudden change in the shape of the coastline such as at a headland. Longshore drift transports beach sediment along a coastline. Longshore drift continues to transport material in the same direction rather than following the coastline. This transports the material out to sea. As the strength of the drift weakens away from the coastline, the sediment is deposited.

Bars and Lagoon

If the bay between two headlands is blocked off by a spit then that spit is known as a bar. The body of water behind the bar is known as a lagoon.

An example of a bar is Slapton Ley in Devon.

Tombolos 

Sometimes a spit extends far enough out to sea to join a coastal island to the mainland. When it does so, the spit is known as a tombolo. An example of this is Chesil beach which joins the Isle of Portland to the south of mainland Britain.

Cuspate forelands

Cuspate forelands, also known as cuspate barriers or nesses in Britain , are geographical features found on coastlines and lakeshores that are created primarily by long shore drift.