The Japanese have been enjoying the bounty of their surrounding seas since ancient times, whether for fish, shellfish or seaweeds. Over thirty varieties of seaweeds plus the numerous products developed from them are regularly used in Japanese cooking.
Most seaweeds contain a surprisingly high percentage (above 50 per cent) of the type of carbohydrate that aids digestion. They also contain iron, calcium, phosphorus and iodine and are rich in vitamins A and C. Seaweed and seaweed products are generally available in dried forms.