This algae is very common in rockpools high up the shore, even managing to survive in the splash zone, out with the regular tidal range. Be careful as gutweed often thrives where enriched water reaches the shore – and by enriched, I mean with agricultural run-off or sewage!
Gutweed is not so good to eat raw, but has great flavour once dried or deep fried, whereby it tastes like its close cousin in the Ulva genus sea lettuce, the crispy seaweed often used in Japanese cuisine. Sprinkle it on salads, sushi or finished dishes like seasoning.