Hosnies Spring
Encyclopedia
Hosnies Spring formerly Hosnie’s Spring or Hosnies Springs) is a wetland
on Christmas Island
, an Australia
n external territory in the eastern Indian Ocean
. It has been recognised being of international importance by designation under the Ramsar Convention on Wetlands
.
was noted in late 1980s. It was incorporated into the Christmas Island National Park
in 1989, and listed on 11 December 1990 as Ramsar site 512, one of two such sites on the island and the smallest in the world. In 2010 a proposal was made to increase the area of the Ramsar site to 202 ha. Justification for its Ramsar designation is because it:
Although some restricted phosphate
mining occurs nearby, human activity has had little impact on the site.
stream
s and seepages emerging from the base of a cliff
on an uplifted
marine terrace
about 24-37 m asl
and 120 m inland from the seaward cliff.
form a wetland supporting a unique 120,000 year-old stand of the mangrove
s Bruguiera gymnorrhiza
and Bruguiera sexangula
. The stand contains between 300-600 trees, including some of the largest Bruguiera ever recorded, several with trunks of more than 80 cm diameter
and with a canopy 30–40 m high. Several species of birds
and crab
s endemic to the island occur on the site.
Wetland
A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....
on Christmas Island
Christmas Island
The Territory of Christmas Island is a territory of Australia in the Indian Ocean. It is located northwest of the Western Australian city of Perth, south of the Indonesian capital, Jakarta, and ENE of the Cocos Islands....
, an Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n external territory in the eastern Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
. It has been recognised being of international importance by designation under the Ramsar Convention on Wetlands
Ramsar Convention
The Ramsar Convention is an international treaty for the conservation and sustainable utilization of wetlands, i.e., to stem the progressive encroachment on and loss of wetlands now and in the future, recognizing the fundamental ecological functions of wetlands and their economic, cultural,...
.
History
Hosnies Spring was known earlier but the unique ecosystemEcosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
was noted in late 1980s. It was incorporated into the Christmas Island National Park
Christmas Island National Park
Christmas Island National Park is a national park occupying most of Christmas Island, an Australian territory in the Indian Ocean southwest of Indonesia. The park is home to many species of animal and plant life, including the eponymous red crab, whose annual migration sees around 100 million...
in 1989, and listed on 11 December 1990 as Ramsar site 512, one of two such sites on the island and the smallest in the world. In 2010 a proposal was made to increase the area of the Ramsar site to 202 ha. Justification for its Ramsar designation is because it:
- is an example of a type of unusual wetland unique to Christmas Island;
- supports a unique assemblage of flora locally restricted to the one location, and additionally several endemic and vulnerable species;
- is of special value for locally restricted species as well as several endemics.
Although some restricted phosphate
Phosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
mining occurs nearby, human activity has had little impact on the site.
Description
The small, 3,300 m2 site comprises permanent freshwaterFreshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
stream
Stream
A stream is a body of water with a current, confined within a bed and stream banks. Depending on its locale or certain characteristics, a stream may be referred to as a branch, brook, beck, burn, creek, "crick", gill , kill, lick, rill, river, syke, bayou, rivulet, streamage, wash, run or...
s and seepages emerging from the base of a cliff
Cliff
In geography and geology, a cliff is a significant vertical, or near vertical, rock exposure. Cliffs are formed as erosion landforms due to the processes of erosion and weathering that produce them. Cliffs are common on coasts, in mountainous areas, escarpments and along rivers. Cliffs are usually...
on an uplifted
Tectonic uplift
Tectonic uplift is a geological process most often caused by plate tectonics which increases elevation. The opposite of uplift is subsidence, which results in a decrease in elevation. Uplift may be orogenic or isostatic.-Orogenic uplift:...
marine terrace
Marine terrace
A marine terrace, coastal terrace, raised beach or perched coastline is a relatively flat, horizontal or gently inclined surface of marine origin, mostly an old abrasion platform which has been lifted out of the sphere of wave activity . Thus it lies above or under the current sea level, depending...
about 24-37 m asl
Above mean sea level
The term above mean sea level refers to the elevation or altitude of any object, relative to the average sea level datum. AMSL is used extensively in radio by engineers to determine the coverage area a station will be able to reach...
and 120 m inland from the seaward cliff.
Flora and fauna
The springsSpring (hydrosphere)
A spring—also known as a rising or resurgence—is a component of the hydrosphere. Specifically, it is any natural situation where water flows to the surface of the earth from underground...
form a wetland supporting a unique 120,000 year-old stand of the mangrove
Mangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
s Bruguiera gymnorrhiza
Bruguiera gymnorrhiza
Bruguiera gymnorrhiza is a small tree up to 10 m high and belongs to the family Rhizophoraceae. It is found on the seaward side of mangrove swamps, often in the company of Rhizophora. Bark is rough and reddish-brown. The tree develops short prop-roots rather than long stilt-roots. Flowers are...
and Bruguiera sexangula
Bruguiera sexangula
Bruguiera sexangula, commonly called the Upriver Orange Mangrove, is a mangrove shrub or tree usually growing up to 15 m, occasionally 30 m, in height.-Description:...
. The stand contains between 300-600 trees, including some of the largest Bruguiera ever recorded, several with trunks of more than 80 cm diameter
Diameter at breast height
Diameter at breast height, or DBH, is a standard method of expressing the diameter of the trunk or bole of a standing tree. DBH is one of the most common dendrometric measurements....
and with a canopy 30–40 m high. Several species of birds
Birds of Christmas Island
The Birds of Christmas Island form a heterogeneous group of over 100 species. There is a core group of ten endemics that have evolved on the remote island in the eastern Indian Ocean for thousands of years, attended by a suite of regular migrants, opportunists and occasional visitors...
and crab
Crab
True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...
s endemic to the island occur on the site.