These pictures show encrusting marine organisms that have attached to the red plastic part of a lobster pot. There is quite a variety. Most of the white elongated tubes are made by a marine worm Spirobranchus triqueter (previously called Pomatoceros triqueter) but there are a couple of coiled tubes which may be Hydroides norvegica. The other small lace-like structures are sea mats or Bryozoa, at least three species, one of which I have never seen before. I am not at all confident with naming Bryozoans. A good series of professional guides for identifying Bryozoa is produced by the Field Studies Council in their Synopses of British Fauna Series; and a good chapter is included in the Handbook of Marine Fauna of North-West Europe by P. J. Hayward and J. S. Ryland (Oxford University Press, 2nd Edition, 2017, Chapter 11, 603 – 637).