Fucus, bladderwrack, rockweed, brown algae

 Good edible seaweed. High in trace minerals. Good for thyroid if iodine deficient.

From  SPECIFIC INDICATIONS FOR HERBS IN GENERAL USE Third edition Michael Moore:

FUCUS 

Fatty degeneration of heart, as an adjunct therapy. Thyroid hypofunction with obesity, fluid retention. Malnutrition, in mineral deficiencies.