What Is Dwarf eelgrass - (Zostera japonica)?
Habitat: Grows on mud or sand in sheltered bays and estuaries
Distribution in Ireland: Coastal Areas
Status: Established
Family name: Zosteracea
Reproduction: Dwarf eelgrass (aka Japanese eelgrass) reproduces by means of pollen grains. A male flower produces the pollen grains, which, via water, have to reach a female flower, where the seeds are subsequently formed.
Dwarf eelgrass
This alien invasive species is believed to have been introduced with a shipment of Japanese oysters some time in the first half of the twentieth century.
Dwarf eelgrass is mainly found in sheltered bays where the seabed is sand, mud or silt. It occurs in the inter-tidal zone and at depths down to about 3 m
Dwarf eelgrass (with flowers) on mud-flats
How To Identify Dwarf eelgrass?
Leaves: Dark green flat & thin
Size: Blade width 1.5 mm
Stems: un-branched stems, and the
Flowers: enclosed on separate shoots.
Dwarf eelgrass root structure
Dwarf eelgrass - Zostera japonica ID guide
Dwarf Eelgrass is a grass-like aquatic plant that forms lush meadows in shallow, sheltered bays and estuaries. These meadows cushion the shoreline from wave energy, delaying the break down of pollutants.
Dwarf eelgrass meadows
Why Is Dwarf eelgrass A Problem?
The intertidal seagrass Dwarf eelgrass (Zostera japonica), which is distributed in intertidal and shallow subtidal zones, is exposed to nutrients from over-enriched land-based discharge and storm water runoff before they can be washed out to sea.
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Dwarf eelgrass colonizes open tidal mud flats, prime foraging grounds for birds.
It slows water currents and traps new sediments.
The dense root system binds soil particles, transforming soft mud into a firm bottom layer.
These changes destroy essential habitat for shrimp and other small mud-dwelling and burrowing animals, many of which are staple prey items for shorebirds.
However, recent studies show some areas of seagrasses can have a beneficial contribution to biodiversity.
European Communities (Birds and Natural Habitats) Regulations 2011 non-native invasive plant species A-Z (Updated 2017)
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There are currently 35 invasive plant species listed in the European Communities (Birds and Natural Habitats) Regulations (annex 2, Part 1)...
Click on a species from the following list to find out more regarding non-native species subject to restrictions under Regulations 49 and 50.
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American Skunk-Cabbage - Lysichiton americanus
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Waterweeds - Elodea (all species)