Why are Seagrasses important?
Article Date: 28 February, 2007
There are many types of crustaceans.
Seagrasses play a pivotal role in the coastal ecosystems of Australia and the world. Seagrasses are particularly important in the sustainability of commercial and recreational fisheries, primarily because of their roles in maintaining sediment stability and water quality, and in providing shelter and food critical to the survival of a wide variety of aquatic biota.
Seagrasses generally grow quickly and produce a large amount of organic material which enters the estuarine food chain. Seagrasses are eaten directly by echinoderms, crustaceans, mollusks and some fish species.
Many species of juvenile fish and crustaceans use seagrasses as nursery areas before moving to other habitats. The postlarvae and juveniles of some fish, such as yellowfin bream, luderick and leatherjackets recruit to, and live in, seagrass habitats.
Because of their particular importance as shelter and habitat to the juvenile life history stages of marine fish and crustaceans, seagrass beds are sometimes referred to as the "nurseries of the sea".
Seagrasses play a pivotal role in the coastal ecosystems
Seagrasses are a fragile habitat, however. While some species of seagrass - such as eelgrass Zostera spp - are comparatively hardy and may recolonise areas after removal, others - such as the strapweed Posidonia australis - do not and are particularly susceptible to impacts. Some species, for example Posidoniaspp, are also now comparatively restricted in their distribution.
Many major estuaries in NSW have lost as much as 85% of their seagrass beds in the past 30 to 40 years. This loss may contribute to declines in the abundance and diversity of fish and in vertebrates in some of these estuaries and the nearby coastal zone.
For more information please visit the following websites:
www.fisheries.nsw.gov.au/__data/assets/pdf_file/5050/protplan_2.pdf
