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Intertidal narrow strap seagrassShort descriptionIntertidal seagrass meadows dominated by the narrow strap seagrass Halodule uninervis. Disclaimer: Ecosystem type descriptions are based on biophysical attributes identified in Central Queensland through expert advice and supported by scientific literature. Not all ecosystem types are mapped based on current inventory, and many of the ecosystems described here may also occur in other parts of Queensland.
Classification categoriesSelect from the links below to view related ecosystem type categories Long descriptionIntertidal seagrass meadows dominated by the narrow strap seagrass Halodule uninervis. Halodule uninervis also includes a wide strap growth form, see type (12). These meadows can also include Zostera muelleri subsp. capricorni*, Cymodocea rotundata, Cymodocea serrulata, Enhalus acoroides, Halodule pinifolia, Halodule uninervis, Thalassia hemprichii, Thalassodendron ciliatum, Halophila spp. and Syringodium isoetifolium. Seagrasses are not a taxonomically unified group, but rather an ecological group that arose through convergent evolution and includes several different families. They are all flowering plants that live underwater and need light to photosynthesise. They also produce seeds. They grow on muds, sands and fine gravels which may be mobile. Meadows may include other structural macrobiota, such as encrusting algae, erect macrophyte algae, bryozoans, sponges and molluscs (e.g. bivalves, cockles, whelks, razor clam beds), together with mobile invertebrate fauna, such as sea cucumbers, crabs (e.g. commercial sand crabs and other portunids) and polychaete worms. Halodule uninervis is typically more enduring than early colonising species of the genus Halophila, but is considered a colonising and opportunistic seagrass forming both transitory and enduring meadows. Transitory meadows increase and decrease in extent and biomass seasonally, and can re-establish following complete loss through sexual reproduction. Enduring meadows may fluctuate but generally remain to some extent through seasons and years. More colonising species typically have fast shoot turnover, short lifespan, fast sexual maturation and development of a (dormant) seed bank. They have low physiological resistance to disturbance but a rapid ability to recover[5]. *Revision of Zostera capricorni has resulted in classification to subspecies. In Queensland, Zostera capricorni has been revised to Zostera muelleri subsp. capricorni[4]. Special valuesSeagrasses provide a wide range of services, including:
Seagrass meadows, particularly those containing H. uninervis and H. ovalis, provide food for dugong[11] and green sea turtles[6]. Dugongs feed mostly on the roots of H. uninervis. Halodule uninervis[11] and H. ovalis [8] are reported to be the most nutritious seagrasses due to high nitrogen and starch content[12]. Grazing of H. uninervis and H. ovalis has been shown to increase production of a nitrogen-rich standing crop[8][1][6]. Diagnostic attributesInundation 'Intertidal – Lower low', 'Intertidal – Mid low', 'Intertidal – Upper low', 'Intertidal – Low undifferentiated', 'Intertidal – Lower medium', 'Intertidal – Upper-medium', 'Intertidal – Medium undifferentiated', 'Intertidal – High', 'Intertidal – Undifferentiated', 'Intertidal – High undifferentiated' although usually occurring below mean sea level Structural macrobiota 'Seagrass – strap narrow' QualifiersSeagrass ecosystems vary in Period and Trend (seasonally and from year to year). The species composition, extent and biomass of seagrass meadows can vary seasonally and between years. The extent and biomass of seagrass meadows along the Queensland east coast are typically maximal in late spring and summer, and minimal over winter[2][3][10]. DistributionThe following relates to distribution of this ecosystem type within the Central Queensland mapping area:
CommentsSee type 12 (intertidal wide seagrass) for detailed discussion of relevant attributes. Additional InformationSeagrass - Queensland Government Case study: Hervey Bay seagrass and dugong - Queensland Government Saltmarshes, seagrasses and algae - Department of Agriculture and Fisheries Seagrass - Queensland Government Seagrasses - Australian Institute of Marine Science (AIMS) A Vulnerability Assessment for the Great Barrier Reef - Great Barrier Reef Marine Park Authority References
Last updated: 22 July 2019 This page should be cited as: Department of Environment, Science and Innovation, Queensland (2019) Intertidal narrow strap seagrass, WetlandInfo website, accessed 30 August 2024. Available at: https://wetlandinfo.des.qld.gov.au/wetlands/ecology/aquatic-ecosystems-natural/estuarine-marine/descriptions/13/ |