Zostera japonica

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Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO 63110 USA

Localities documented in Tropicos sources

Zostera nana Roth:
China (Asia)
Madagascar (Africa & Madagascar)
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

References:

Anonymous. 1986. List-Based Rec., Soil Conserv. Serv., U.S.D.A. Database of the U.S.D.A., Beltsville.
Jumelle, H. 1950. Potamogetonacees. Fl. Madagasc. 21: 1–16.

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Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO 63110 USA

Range Description

Zostera japonica occurs in the western Pacific from the Russian Federation to southern Vietnam, including Japan and much of coastal China.

In the eastern Pacific, Z. japonica occurs from Vancouver Island south to San Francisco, California, USA, and is believed to be introduced.

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International Union for Conservation of Nature and Natural Resources

National Distribution

Canada

Origin: Exotic

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

United States

Origin: Exotic

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

Source:

NatureServe

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NatureServe

Herbs, annual, rarely perennial. Rhizomes 0.5--1.5 mm thick; roots 2 at each node. Leaves: sheath open, persistent, 3--5.5 cm, membranous flaps 2; blade to 15 cm ´ 1--1.5 mm, apex obtuse or retuse; veins 3. Generative shoots lateral, mostly unbranched, with 1--5 spathes. Inflorescence: peduncles with adnate portion 20--90 mm, free portion 1.2--3.1 cm; spathes 2--5, sheath 2--4 cm ´ 2--2.5 mm; blade 5--10 cm; spadix lanceolate; staminate flowers 5--7; pistillate flowers 5--8, apex obtuse. Staminate flowers: bracts subtending every flower; pollen sacs 0.5 ´ 0.7 mm. Pistillate flowers: ovary 1.5--2 mm; style 1--2 mm. Fruits ellipsoid, 2.5 mm, beaked.

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Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO, 63110 USA

Diagnostic Description

Synonym

Zostera americana Hartog

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Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO, 63110 USA

Habitat

Habitat and Ecology

Zostera japonica is found in broadly sheltered bays on sandy or muddy coasts from 1-3 m depth along cool to subtropical sea coasts of eastern Asia (Miki 1933).

This is a small seagrass. In Japan, it is always found in the uppermost parts of the bed, as its main habitat is intertidal flats. Biomass varies greatly with season: a maximum biomass of 270 g dry weight/m² was recorded in July and a minimum of 30 g dry weight/m² occurred from December to January. Mainly distributed in the intertidal zone around islands in South Korea. In the Pacific coast of North America, it commonly grows higher in the intertidal zone and has an open leaf sheath, characteristic of its subgenus Zosterella. Zostera japonica is restricted in its northerly extent where it is found primarily in the upper intertidal zones in muddy or silty substrates.

In Hong Kong, Zostera japonica occurs intertidally. Local macroalgal blooms usually occur during the winter and coincide with sloughing of Zostera leaves. Clithon spp. are the most abundant gastropods in the local beds and are the dominant grazers on epiphytic algal growth on Zostera leaves. This grazing is important to the maintenance of the Z. japonica beds in Hong Kong (Fong et al. 2000).

Systems

Marine

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International Union for Conservation of Nature and Natural Resources

Habitat & Distribution

Flowering early fall. Intertidal marine waters; -2--0 m ; introduced; B.C.; Wash.; Asia.

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Barcode of Life Data Systems (BOLD)

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Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO, 63110 USA

Molecular Biology

Barcode data: Zostera japonica

The following is a representative barcode sequence, the centroid of all available sequences for this species.

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Barcode of Life Data Systems

Statistics of barcoding coverage: Zostera japonica

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 4
Specimens with Barcodes: 4
Species With Barcodes: 1

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Barcode of Life Data Systems (BOLD)

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Barcode of Life Data Systems

Conservation Status

IUCN Red List Assessment

Red List Category

Least Concern

Red List Criteria

Version

3.1

Year Assessed

2010

Assessor/s

Carruthers, T.J.B., Short, F.T., Waycott, M., Kendrick, G.A., Fourqurean, J.W., Callabine, A., Kenworthy, W.J. & Dennison, W.C.

Reviewer/s

Livingstone, S., Harwell, H. & Carpenter, K.E.

Contributor/s

Justification

This species is widespread and common in intertidal areas. It is threatened a local level in some areas by human activities. It has increased its range and now is an invasive on the west coast of Northern America. This species is listed as Least Concern.

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http://creativecommons.org/licenses/by-nc/3.0/

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International Union for Conservation of Nature and Natural Resources

NatureServe Conservation Status

Rounded Global Status Rank: GNR - Not Yet Ranked

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NatureServe

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NatureServe

National NatureServe Conservation Status

Canada

Rounded National Status Rank: NNA - Not Applicable

United States

Rounded National Status Rank: NNA - Not Applicable

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NatureServe

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NatureServe

Trends

Population

This is a common and widespread species. Overall, the population for this species is increasing. There has been reported decline in Korea due to land reclamation.

Zostera japonica is an introduced species on the west coast of North America that came in with shipments of oysters used to support the local shellfish industry (Phillips and Shaw 1976). First reported from Willapa Bay, Washington, it spread throughout coastal Washington and now occurs from the southern coast of British Columbia, Canada to Coos Bay, Oregon (Harrison and Bigley 1982, Posey 1988) and Humboldt Bay, California (F. Short pers. obs.).

Population Trend

Increasing

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International Union for Conservation of Nature and Natural Resources

Threats

Major Threats

In some parts of its range, mostly in Korea, Zostera japonica is threatened by aquaculture and hardening of shorelines (land reclamation). It is also affected by resuspended sediments that affect water quality.

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International Union for Conservation of Nature and Natural Resources

Management

Conservation Actions

The distribution of Zostera japonica falls into protected areas in South Korea (Environmental Conservation Areas or Special Coastal Management Areas).

This species is protected in Washington state (USA).

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