Zostera japonica

Photo courtesy: California Sea Grant

Synonyms: Nanozostera japonica (Asch. & Graebn.) P. Toml. & U. Posl.

Common names: dwarf eelgrass; Japanese eelgrass

Zostera japonica (=Nanozostera japonica, dwarf eelgrass) is an aquatic plant that forms dense stands in shallow, sheltered bays and estuaries. Populations of Z. japonica have been found in Humboldt County. Z. japonica often invades areas with little or no natural or human disturbance and also shows a positive relationship with disturbance. Z. japonica lives as an annual, overwintering as buried seeds, or a short-lived perennial. It reproduces vegetatively through rhizomatous cloning and sexually through seed production. The dispersal of the seeds, both within and between estuaries, may be aided by waterfowl species.  Z. japonica has been shown to rapidly expand in the spring and summer.  

Rating: Moderate

Cal-IPC Resources

  • Plant Assessment Form - Information gathered by Cal-IPC on the impacts, rate of spread, and distribution of invasive plants in California. Does not include management information.
  • CalWeedMapper - Statewide maps, climate models, and reports.
  • Cal-IPC News - Our quarterly newsletter. Each issue is available as a pdf.
  • Cal-IPC Symposium Proceedings - Presentations and papers from our annual Symposium.
  • Don't Plant a Pest! - Select your region to find non-invasive alternatives to ornamental species. Also see our statewide brochure on trees.

    Other Resources

    Symposium Presentations

    • None for this species

    Cal-IPC News Articles

    • Brusati, E. (2011). Cal-IPC Inventory update adds eight plants. Cal-IPC News. 19: 18.