Thrown from sea onto beach. This piece about four inches long.
No interactions present.
Yes, a tough call but paired bladders on a damaged frond at the strandline (hence the colour)
Ref the fist ID http://www.marlin.ac.uk/speciesinformation.php?speciesID=2632
Lat/Lng: 50.5, -2.5
OS grid ref: SY6677