Ecklonia cava is an edible brown seaweed from Japan and Korea. Try checking out Asian stores. The Japanese name is noro kajime. I just checked in several shops in the Netherlands and they don't have it.
If you do get to find it, please email me. Thanks!
Ecklonia cava by: tomas
Miyeok in Korean. I may be wrong, but seaweed is a natural food in Korea. Koreans would make soup out of this seaweed and would serve it on birthdays as thanksgiving for their mother for giving birth to them. It represents the umblilical cord from mother to a baby. Nowadays, you can see it served as part of Korean food. You can buy it in any Korean mart.