Coastal protection schemes protect the habitats of plant and wildlife, which cannot be replaced.
The arguments against sea defence schemes are…
Most sea defence schemes are expensive to build and maintain, and this money is taken from taxpayers. Some people say their money is wasted, because the coastal defences themselves will eventually be eroded away. Coastal defences create visual pollution, and ruin the natural atmosphere of the beach. Also, if they are poorly maintained, they may pose a hazard to swimmers and sunbathers.
Methods of protecting the coast are:
Sea wall. This is a barrier that reflects the waves and withstands storms, completely protecting the cliff. Although they effectively reduce erosion, they are costly at £6000 per metre, and spoil the natural view of the coast.
Beach Re-building. The sand on a beach inhibits the sea from eroding the coast as much, by absorbing some energy from the waves as they hit the shore and slows them down as they go up the slope to the cliff. This costs £3 per cubic metre. Groynes are small walls that jut out into the sea to stop the sand (that protects the cliff) being washed away. These cost £10000 each. But as groynes collect sand to stop it from being carried away, the amount of sand on the other side of the coast decreases, and can create more of a hazard there.
Revetment. A revetment is like a sloping sea wall that is laid along the coast. It absorbs the energy of the waves as a beach would. These cost £2000 per metre.
Offshore breakwater. This is a small wall made of concrete or other interlocking material built out to sea, and positioned below the low water mark. It guards the coast from all waves, as they break on the breakwater instead of on the coast. These cost about £5000 per metre.
Rip-rap. These are artificial interlocking boulders that defend the coast by breaking up the waves to minimise erosion. They cost £3500 per metre.
Gabions. These are strong wire cages filled with stones. They act like a sea wall and look more natural as they slowly get covered with grass and sand. These cost £100 per metre.
I think beach rebuilding is the best option because it is cheapest, natural, and protects the cliffs effectively.