There are four main kinds of seaweeds in Hong Kong. They are "Halophila beccarii" (), "Halophila ovalis" (), "Ruppia maritimia" () and Dwarf eelgrass "Zostera japonica" () among which "Zostera japonica" was first found in Lai Chi Wo in 1979. Lai Chi Wo is the only place, and also the largest bed that we can find this kind of seaweed. This seaweed bed mat the shore for more than 2 hectares on the wild open mudflat. Seaweeds are precious in Hong Kong which mainly grow along the coast of northwest and northeast of New Territories. Seaweeds hold great importance to the eco-system because it provides shelter, food and feeding place for animals living along the coast, and besides, seaweeds can prevent soil and sand from being washed away.