Laminaria japonica is a long, flat leaflike body, brown-green, with two longitudinal grooves running through the middle of leaves, forming a middle zone, which is generally 1.5-3m long and 15-25cm wide, with the longest being 6m and the width being 50cm.
Kelp belongs to the sub-frigid zone algae, which is endemic to the North Pacific Ocean, and there are some kelp distributed in the Atlantic Ocean. Most of kelp is distributed in the northern hemisphere, while a small amount is distributed in the southern hemisphere, which generally grows on seabed rocks in the subtidal zone. The growth of kelp is mainly affected by temperature, light, nutrients and plant hormones.
The Pacific Northwest is the concentrated growth place of kelp, and most kinds of kelp in the world are distributed here. Among them, the kelp with the greatest economic value is distributed in the western coast of tatar strait, Russia and the coastal waters of Hokkaido, Japan.
Extended data
Kelp is for food. There are various amino acids in protein of kelp, especially eight essential amino acids for human body, and their contents are very close to the model of essential amino acids in ideal protein. Kelp can be used not only as a dish, but also as a variety of food with unique flavor.
Adding kelp powder into the feed can effectively improve the nutritional structure, reduce the feeding cost, increase the weight, increase the egg production rate, reduce the mortality rate and improve the quality of raised varieties.
As industrial raw materials, fucoidan, mannitol, dietary fiber and sodium alginate were extracted from kelp.
China has been cultivating kelp since 1950s. Since the artificial raft culture of kelp was developed, autumn seedlings, summer seedlings, early autumn seedlings, summer seedlings, spring seedlings and two-year seedlings have been tested and produced successively, and the seedling production has been deeply explored. It is mainly divided into conventional seedling raising techniques and kelp gametophyte seedling raising techniques.