It is a law enshrined in the 1949 Coastal Protection Act, curbing historic losses of hundreds of thousands of tonnes of sediment from beaches by people extracting "free" sediment for building materials.
commercial level activities are mentioned early on as the very raison d'etre for these laws existing, and
in a top level comment is that text is extracted from the top linked article or from a given link (and no link was provided) not that such text might be found somewhere on the internet.
That aside, portions of the Solway Firth are perhaps an exception if commercial harvesting is permitted given the law in question:
is riddled with carve outs for Wales and Scotland (Solway being Scotland to the north and England to the south) along with clauses allowing local authorities to issue licences to permit activities, and Section 18 (1) .. unlawful to excavate or remove any materials .. (subject to exceptions following) ending with (11) Nothing in this section shall be construed as authorising a coast protection authority in Scotland to institute proceedings for any offence under this Act.
From: www.sciencealert.com/scientists-reveal-why-you-should-never-take-pebbles-from-the-beach
commercial level activities are mentioned early on as the very raison d'etre for these laws existing, and> There are extensive areas in the Solway Firth
doesn't appear at all in the sciencealert.com version linked, nor in the original at https://theconversation.com/why-you-shouldnt-take-pebbles-fr...