What does it look like?
Spartina are grass species commonly found in estuarine environments, growing in dense clumps reaching heights of up to 1.5 metres. There are two primary species: Sporobolus alterniflorus (formerly Spartina alterniflora), which is the more robust of the two, with shoots measuring up to 30mm in diameter; and Sporobolus anglicus (formerly Spartina anglica), which is smaller, with shoots up to 8mm in diameter.
Leaf colour can vary, ranging from yellow to green or brown depending on environmental conditions. Spartina also features an extensive rhizome system, consisting of underwater or underground creeping stems that enable the plant to spread and stabilise within its habitat.
Why is it a problem?
Spartina is a highly aggressive and persistent invader of intertidal mudflats. It has the ability to spread inland to wetlands and stream margins, where it can outcompete and displace native vegetation, resulting in the loss of important habitat for shorebirds. Its presence may also impact recreational fisheries and traditional kai moana gathering areas.
The dense growth of Spartina traps sediment, which can gradually raise the ground level to the point where the area is no longer intertidal. In severe cases, large infestations can contribute to surface flooding on adjacent land. Spartina is remarkably resilient, tolerating a wide range of weather conditions, temperatures, fire, grazing, and physical disturbance.
In New Zealand, Sporobolus alterniflorus is not known to produce seed, while Sporobolus anglicus produces only limited quantities. Both species primarily reproduce vegetatively through extensive rhizome networks, and even small fragments can easily resprout and establish new growth.
Control methods
If you think you have found Spartina, contact us at biosecurity@hbrc.govt.nz or 06 835 9200.
More information
Five spartina species are listed as an Exclusion pests in the Hawke’s Bay Regional Council Regional Pest Management Plan 2018-2038.
Spartina is not known to exist in Hawke’s Bay.
Related links
Spartina alterniflora • New Zealand Plant Conservation Network
Hawkes Bay Regional Pest Management Plan 2018-2038
Management Programme
Unwanted Organism
An unwanted organism is any organism that's capable of causing harm to natural or physical resources (like forests and waterways) or human health. A number of introduced pests in New Zealand are classed as unwanted.
Exclusion Programme
To prevent the establishment of the subject, or an organism being spread by the subject, that is present in New Zealand but not yet established in an area.
Taxonomies
FamilyPoaceae
TypePlants
GroupClimber
HabitatLand
Management ProgrammeUnwanted OrganismExclusion Programme
