| Common Names |
Eelgrass, Wrack Grass, Marine Eelgrass, Sea Grass
|
| Phylum |
Anthophyta: Flowering plants
|
| Class |
Liliopsida: Monocotyledons
|
| Family |
Zosteraceae
|
| Elevations |
Lower intertidal, subtidal to -4m chart datum.
|
| Distribution |
Alaska to Mexico, Greenland to the Carolinas, throughout Europe and eastern Asia.
|
| Community |
Estuaries, isolated saline water, coastal wave protected areas.
|
| Substrate |
Rooted in mud, muddy sand or muddy gravel.
|
| Salinity |
18 to 40 psu
|
| Reproduction |
Protogynous hermaphrodite, vegetative reproduction by growth of rizome.
|
| Develpomental mechanism |
Oviparous
|
| Reproductive window |
May through September
|
| Dispersal |
Detached plants and rhizomes float; rhizome roots can take root on suitable substrate.
The generative stalk can be released with the seed compliment for dispersal (Phillips and Menez, 1998).
Seeds attached to gas bubbles have potential for dispersal up to 100's of metres.
Wildfowl dispersal: through attachment or ingestion.
Transplanting supervised by qualified professionals.
|
| Size |
Typically 20 to 50cm (occasionally up to 200cm) in length; 5 to 11mm wide.
|
| Description |
Long, narrrow, dark green, flowering grass like plant. Root system: creeping rizome. Leaves and rhizomes contain air spaces, lacunae, that aid buoyancy. Reproductive shoot, terminal, branched and up to 15 m long.
|
| Duration |
Perennial; may act as annuals under stressful conditions
|
| Growth |
Long leaves found in summer are relplaced by shorter, slow growing leaves in winter. Leaf characteristics may also vary according to environmental conditions.
|
| Wave-Exposure |
Low Tolerance
|
| Habitat Significance |
Zostera beds are important for sediment deposition, substrate stabilization, as substrate for epiphytic algae and micro-invertebrates, and as nursery grounds for many species of economically important fish and shellfish. Zostera is also an important food for certain species of waterfowl.
|
| Mistaken Identity |
Zostera japonica
|
| Typical Abundance |
High density, growing over dense stretches of inter and subtidal beach.
|
| Importance |
Habitat for a biodiverse variety of fish, invertibrates and algae. it is estimated that approximately 80 percent of all commercial fish and shellfish species depend on eelgrass habitat for at least part of their lifecycle. Zostera plays an important role in stabilizing soft marine sediments.
|
| Additional Use Use |
Historical industrial use of eelgrass has been replaced with synthetic material as a consequence of abundance decline due to human impact and microbial pathogens/parasites destroying large amounts of Zostera across North America and Europe.
|
| Protection |
Eelgrass is now considered essential fish habitat and consequently is protected under section 35 of the federal Fisheries Act.
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