Zostera japonica is a species of aquatic plant in the Zosteraceae family.[
It is referred to by the common names dwarf eelgrass]
Distribution and habitat
It is considered native in the Russian Far East (Sakhalin, Kamchatka, Primorye, and the Kuril Islands), Japan, Korea, China, the Ryukyu Islands, Taiwan and Vietnam. It was first reported as being naturalized in British Columbia and in the United States State of Washington,[ Heinrich Gustav Adolf Engler. 1907. Das Pflanzenreich 31(IV. 11): 32. Zostera japonica][Hartog, Cornelis den. 1970. Verhandelingen der Koninklijke Nederlandsche Akademie van Wetenschappen. Afdeeling Natuurkunde, Sectie 2. Amsterdam 59(1): 74.; Sea-Grasses of the World, Zostera americana][Tomlinson, Philip Barry & Posluszny, Usher. 2001. Taxon 50(2): 432, Nanozostera americana and Nanozostera japonica] but is now considered Invasive species as far south as California. It is believed to have been introduced with a shipment of Pacific oyster some time in the first half of the twentieth century.[ This seagrass is mainly found in sheltered bays where the seabed is sand, mud or silt. It occurs in the intertidal zone and at depths down to about .]
Ecology
Japanese eelgrass is a small species and usually grows on the upper edge of seagrass meadow, typically on mudflats exposed at low tide. The plants lose many of their leaves in the winter.
On the west coast of North America, the non-native Japanese eelgrass is now found in the same habitats as the native common eelgrass ( Zostera marina), growing beside it and sometimes displacing it. The habitat in which they both occur is used by economically important shellfish. Further research is needed to clarify the roles of the two species in the habitat and whether any management strategies are needed to protect the native species from the invasive species.
