Coral sand
Encyclopedia
Coral sand is sand
of particles originating in tropical and sub-tropical marine
environments from bioerosion
of limestone
skeletal material of marine organism
s. One example of this process is that of parrot fishes which bite off pieces of coral
, digest the living tissue
, and excrete the inorganic component as silt and sand
. However, the term "coral" in coral sand is used loosely in this sense to mean limestone of recent biological origin; corals are not the dominant contributors of sand particles to most such deposits. Rather, remnant skeletal fragments of foraminifera
, calcareous algae, molluscs, and crustaceans can predominate. Because it is composed of limestone, coral sand is acid-soluble.
. Many Comoros
beaches have been scarred by sand mining. Over 250 tons of shells and corals were exported from Tanzania
in 1974. Exploitive collection has moved from the depleted areas off Tanzania and Kenya
to the islands of Zanzibar
and Mafia
.
Such extensive mining can be very harmful to reef ecosystem
s and beaches.
In an effort to prevent damage from reef sand minding, the Convention on international trade in endangered species urged parties to the convention to work for the conservation and sustainable use of the coral reef ecosystems.
Sand
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...
of particles originating in tropical and sub-tropical marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
environments from bioerosion
Bioerosion
Bioerosion describes the erosion of hard ocean substrates – and less often terrestrial substrates – by living organisms. Marine bioerosion can be caused by mollusks, polychaete worms, phoronids, sponges, crustaceans, echinoids, and fish; it can occur on coastlines, on coral reefs, and...
of limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
skeletal material of marine organism
Organism
In biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...
s. One example of this process is that of parrot fishes which bite off pieces of coral
Coral
Corals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...
, digest the living tissue
Biological tissue
Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...
, and excrete the inorganic component as silt and sand
Sand
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...
. However, the term "coral" in coral sand is used loosely in this sense to mean limestone of recent biological origin; corals are not the dominant contributors of sand particles to most such deposits. Rather, remnant skeletal fragments of foraminifera
Foraminifera
The Foraminifera , or forams for short, are a large group of amoeboid protists which are among the commonest plankton species. They have reticulating pseudopods, fine strands of cytoplasm that branch and merge to form a dynamic net...
, calcareous algae, molluscs, and crustaceans can predominate. Because it is composed of limestone, coral sand is acid-soluble.
Environmental issues
Coral sand mining is a significant industry in some areas, and can have damaging environmental effects. Over 500,000 tons of coral sand are mined annually from MauritiusMauritius
Mauritius , officially the Republic of Mauritius is an island nation off the southeast coast of the African continent in the southwest Indian Ocean, about east of Madagascar...
. Many Comoros
Comoros
The Comoros , officially the Union of the Comoros is an archipelago island nation in the Indian Ocean, located off the eastern coast of Africa, on the northern end of the Mozambique Channel, between northeastern Mozambique and northwestern Madagascar...
beaches have been scarred by sand mining. Over 250 tons of shells and corals were exported from Tanzania
Tanzania
The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...
in 1974. Exploitive collection has moved from the depleted areas off Tanzania and Kenya
Kenya
Kenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east...
to the islands of Zanzibar
Zanzibar
Zanzibar ,Persian: زنگبار, from suffix bār: "coast" and Zangi: "bruin" ; is a semi-autonomous part of Tanzania, in East Africa. It comprises the Zanzibar Archipelago in the Indian Ocean, off the coast of the mainland, and consists of numerous small islands and two large ones: Unguja , and Pemba...
and Mafia
Mafia Island
Mafia Island is part of the Tanzanian Spice Islands, together with Unguja and Pemba. As one of the six districts of the Pwani Region, Mafia Island is governed from the mainland, not from the semi-autonomous region of Zanzibar, of which it has never been considered to be a part.According to the...
.
Such extensive mining can be very harmful to reef ecosystem
Ecosystem
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....
s and beaches.
In an effort to prevent damage from reef sand minding, the Convention on international trade in endangered species urged parties to the convention to work for the conservation and sustainable use of the coral reef ecosystems.