used in topical beauty treatments. See also Fucoidan. Wakame is a rich source of eicosapentaenoic acid, an omega-3 fatty acid. At over 400 mg/(100 kcal) or almost 1 mg/kJ, it has one of the higher nutrient-to-energy ratios for this nutrient, and among the very highest for a vegetarian source. A typical 10–20 g (1–2 tablespoon) serving of wakame contains roughly and provides 15–30 mg of omega-3 fatty acids. Wakame also has high levels of sodium, calcium, iodine, thiamine and niacin. In Oriental medicine it has been used for blood purification, intestinal strength, skin, hair, reproductive organs and menstrual regularity. In Korea, the soup miyeokguk is popularly consumed by women after giving birth as sea mustard () contains a high content of calcium and iodine, nutrients that are important for new nursing mothers. Many women consume it during the pregnancy phase as well. It is also traditionally eaten on birthdays for this reason, a reminder of the first food that the mother has eaten and passed on to her newborn through her milk. Aquaculture Japanese and Korean sea-farmers have grown wakame for centuries, and are still both the leading producers and consumers. Wakame has also been cultivated in France since 1983, in sea fields established near the shores of Brittany. Wild-grown wakame is harvested in Tasmania, Australia, and then sold in restaurants in Sydney and also sustainably hand-harvested from the waters of Foveaux Strait in Southland, New Zealand and freeze-dried for retail and use in a range of products. Cuisine Wakame fronds are green and have a subtly sweet flavour and satiny texture. The leaves should be cut into small pieces as they will expand during cooking. In Japan and Europe, wakame is distributed either dried or salted, and used in soups (particularly miso soup), and salads (tofu salad), or often simply as a side dish to tofu and a salad vegetable like cucumber. These dishes are typically dressed with soy sauce and vinegar/rice vinegar. Goma wakame, also known as seaweed salad, is a popular side dish at American and European sushi restaurants. Literally translated, it means 'sesame seaweed', as sesame seeds are usually included in the recipe. Invasive species Native to cold temperate coastal areas of Japan, Korea, China, and Russia, in recent decades it has become established in temperate regions around the world, including New Zealand, the United States, Belgium, France, Great Britain, Spain, Italy, Argentina, Australia and Mexico.