No interactions present.
Live ormers can be found at very low spring tides - they are collected for eating but need to be a certain size (there is a special ormer gauge!)
Clearly a UK Post but located in Guernsey - clever then!
I don't think it can be anything other than an Aberlone - the Ormer. Range Med to Channel Isles; the NBN link is clear enough (but which might lie!).
Here's World distribution http://www.gbif.org/species/2293076 showing how inaccurate one or other is and how we should be VERY careful about using information from the Internet! How can so many people be wrong?
Note that there are at least four sub-species.
There's a good treatise here http://www.glaucus.org.uk/ormer.htm
This would make me want to be a collector http://www.idscaro.net/sci/05_hali/species/tuberculata_lamellosa.htm
Lat/Lng: 49.4758, -2.4544
OS grid ref: S^671529