around 5-8cms in length
No identification made yet.
No interactions present.
Is a brown, unbranched seaweed with fine white hairs in summer.
There is another possibility, Halosiphon tomentosus, a northern species which I have not seen in the field.
Google both and see what you think.
Lat/Lng: 56.889, -6.183
OS grid ref: NM453853