The purpose of taking the photos is to have a good record of what the coastal environment is like now. This includes the inter-tidal zone, beach, sand dunes, vegetation, tracks, any built structures, development of roads and drainage.
In the future people can take photos of the same locations and see if there are changes. Once they have found changes they can then investigate the causes. This process should be able to identify problems more quickly than if there is no photographic recorded information about an area.