A small seaweed with rigid fronds and a calcareous feel. This was observed in a rock pool.
No interactions present.
Correct your ID mbf45 and I'll agree.
You can often tell something is wrong by the lack of links (Wiki,NBN etc) in the ID panel.
Lat/Lng: 50.224970599758, -5.3923988342285
OS grid ref: SW581416