I have never seen this before. Cormorants gather on a drifting giant kelp paddy on the open ocean where I saw them diving below then coming up in the kelp rubbing their backs on the seaweed. Another example of giant kelp being used to clean and/or remove parasites from an animal?
Phalocrocorax & Macrocystis pyrifera paddy 2014 10-09 SB Channel-001
A drifting paddy of giant kelp with a Heermann's gull on top and a California sea lion in the water. Giant kelp paddies like this are oasis for life on the open ocean.
Macrocystis pyrifera drifting paddy Zalophus & Larus heermanni 2014 09-09 SB Channel-x-014
A close up look at a drifting giant kelp plant that continues to actively grow as indicated by several apical fronds. The rapid growth tips of the stipes are an array of fronds that show a gradient in bladder (pneumatocyst) sizes as the fronds each grow larger in turn
Macrocystis pyrifera floating paddy apical fronds 2014 07-15 SB Channel-009
A wide view of a drifting giant kelp plant (and some green surfgrass in the lower corner). Giant kelp may become detached from the shallow rock reefs on which they live by big surf
Macrocystis pyrifera floating paddy apical fronds 2014 07-15 SB Channel-006