11/1/2010
The Edge of Existence programme today turned its focus to coral reefs. Interestingly, or perhaps even alarmingly, 3 popular aquarium corals species were included in their list of the top 10 coral species.
Catalaphyllia jardinei, Elegance Coral, Heliofungia actiniformis, Long Tentacled Mushroom Coral, and Physogyra lichtensteini, Pearl bubble Coral, were all identified as being at risk to some extent, because of their popularity as aquarium corals.
List of top 10 endangered coral species:
Elegance Coral
Catalaphyllia jardinei is a beautiful zooxanthellate coral that is found in the Indian and Pacific Oceans. Although it is found across a wide geographical range this species is rare. The striped oral disc and green tentacles with pink tips give it a distinctive appearance and it may be found as individual polyps or in colonies. This species is considered as evolutionarily distinct and has a long fossil history. A popular coral in the aquarium trade, over-harvesting to supply the aquarium market is the biggest threat to Catalaphyllia jardinei. Like other corals it is also threatened by coral bleaching, ocean acidification and damage from human activities such as destructive fishing, pollution and coastal development.
Crisp Pillow Coral
Anomastraea irregularis is an encrusting or submassive coral that is found in the western Indian Ocean. This zooxanthellae coral can grow to heights of 20cm and is found at the base of shallow reefs showing a preference for sandy substrates and turbid water. This species is blue-grey or cream in colour and its tentacles are often extended during the day. Anomastraea irregularis is the only species of its genus and its closest relative is also a monospecific genus, it is therefore regarded as highly evolutionarily distinct. In addition to threats of coral bleaching and ocean acidification this species is thought to be particularly vulnerable to the voracious predator of coral, the Crown-of-Thorns-Starfish. Over fishing, destructive dynamite fishing, coral bleaching and ocean acidification are also threats to this species.
Horastrea Coral
Horastrea indica is a massive colonial coral species that is only found in the Western Indian Ocean in places such as Mozambique, Tanzania, Madagascar and some other smaller islands in the region. It is a rare species and as such, there is little information about Horastrea indica beyond that it is a zooxanthellate coral. Pale brown with blue-grey oral discs this species is found in sandy reef areas. Current threats to the population include destructive fishing, over fishing, pollution from sewage and coastal run-off, Crown-of-Thorn starfish, cyclones and coral bleaching. The frequency of cyclones and coral bleaching is exacerbated by the current change in global climate. There are currently no specific conservation measures underway for this species.
Pillar Coral
Dendrogyra cylindrus is a distinctive coral that grows in grey-brown or olive cylindrical columns that have a hairy appearance. This species is uncommon, but is found in the western Atlantic across the Caribbean, Gulf of Mexico and Bahamas, preferring to grow in flat or gently sloping habitats. Dendrogyra cylindrus belongs to an evolutionarily distinct genus and is monospecific. Reproduction occurs by spawning or fragmentation but juvenile recruitment is low. Listed as vulnerable on the IUCN Red List of Threatened Species the current threats include disease, coral bleaching and ocean acidification. Although there is no specific conservation of this species it is protected within marine protected areas that occur throughout its geographical range.
Elliptical Star Coral
Parasimplastrea sheppardi is a colonial, zooxanthellae coral found in the Indian Ocean and Arabian and Iranian Gulfs. Brown and green in colour this species is found in a variety of reef habitats down to depths of 20m. Parasimplastrea sheppardi is distinct from other species in its family and is monospecific. The population is thought to be in decline. Threats to Parasimplastrea sheppardi include global threats such as coral bleaching and ocean acidification. Regional threats include cyclones such as Cyclone Gonu that caused extensive damage in 2007 to the Oman coast and eutrophication which has lead to massive algae blooms that reduce water quality and light availability on coral reefs. Current conservation measures include a Global Coral Reef Monitoring Network (GCRMN) and some Marine Protected Areas (MPAs) but the current network of MPAs needs to be expanded and effectively managed.
Mushroom Coral
Heliofungia actiniformis is an attractive free-living coral that is popular within the aquarium trade. This zooxanthellate, gonochoric coral broods larvae before spawning, but can also reproduce asexually by a process called budding. Found in the Indian and Pacific Ocean this species is often found in shallow or lagoon habitats but can be found down to depths of 25m. This species has a basal lineage within the Fungiidae, is monospecific and is only closely related to one other species. The major threat to this species is the aquarium trade with up to 44,650 wild pieces being exported each year from Indonesia. Other threats include coral bleaching and ocean acidification. There are a number of MPAs and conservation initiatives in place in the region in which this species is found.
Parasimplastrea Coral
Parasimplastrea sheppardi is a colonial, zooxanthellae coral found in the Indian Ocean and Arabian and Iranian Gulfs. Brown and green in colour this species is found in a variety of reef habitats down to depths of 20m. Parasimplastrea sheppardi is distinct from other species in its family and is monospecific. The population is thought to be in decline. Threats to Parasimplastrea sheppardi include global threats such as coral bleaching and ocean acidification. Regional threats include cyclones such as Cyclone Gonu that caused extensive damage in 2007 to the Oman coast and eutrophication which has lead to massive algae blooms that reduce water quality and light availability on coral reefs. Current conservation measures include a Global Coral Reef Monitoring Network (GCRMN) and some Marine Protected Areas (MPAs) but the current network of MPAs needs to be expanded and effectively managed.
Pearl Bubble Coral
Physogyra lichtensteini is easily recognised by the white bubble shaped vesicles that cover the surface of this large zooxanthellate, colonial species. Physogyra lichtensteini come from a long evolutionary branch and is located in a group of species that are all very different to each other. Distributed widely across the Indian and Pacific Oceans this species can often be found in turbid water and in crevices and overhangs. Physogyra lichtensteini is a gonochroistic, which means each polyp is either male or female, but not both like many other species are. Listed as vulnerable by the IUCN the primary threats to this species are coral bleaching, ocean acidification, collection for the aquarium trade, coastal development, over-fishing pollution and sedimentation.
Ctenella Coral
Ctenella chagius is a member of the small Meandrinidae family and found exclusively in the Chagos Archipelago, Mauritius and La Réunion. Ctenella chagius grows in hemi-spherical colonies, which may be cream, green or light brown in colour. This species can be found on reef slopes and in lagoons at depths ranging between 3 and 45m. There is no population information for this species but it is thought to be in decline and is listed as endangered on the IUCN Red List of Threatened Species. Like other corals Ctenella chagius is threatened by coral bleaching and ocean acidification. The recently designated Chagos Archipelagos Marine Protected Area, an area of 210,000 miles2, now provides considerable protection from direct human.
Elkhorn Coral
Acropora palmata is an important reef building coral in the Caribbean and has distinctive ‘antler’ like branches, which are yellowy-tan in colour. Able to grow up to 2m in height and 4m in width Acropora palmata can dominate the coral reef but its populations have suffered massive declines in the past 30 years due to disease such as White Band disease, coral bleaching and storm damage. Restoration efforts include creation and extension of Marine Protected Areas and propagation projects where fragments of coral are re-attached and grown.
About the EDGE of Existence Programme
The EDGE of Existence programme is the only global conservation initiative to focus specifically on threatened species that represent a significant amount of unique evolutionary history.
Using a scientific framework to identify the world’s most Evolutionarily Distinct and Globally Endangered (EDGE) species, the EDGE of Existence programme highlights and protects some of the weirdest and most wonderful species on the planet. EDGE species have few close relatives on the tree of life and are often extremely unusual in the way they look, live and behave, as well as in their genetic make-up. They represent a unique and irreplaceable part of the world’s natural heritage, yet an alarming proportion is currently sliding silently towards extinction unnoticed.
The aim of the EDGE programme is to put these species on the map and catalyse conservation action to secure their future. Each year a number of the most poorly known and neglected EDGE species are selected for conservation attention. You can learn more about these species in the Species and Conservation sections of this website, and donate towards targeted conservation actions in the Support section. Where virtually nothing is known, ZSL-led expeditions often represent the first step in determining whether rare and cryptic EDGE species still survive. Longer-term surveys are carried out by EDGE Fellows (aspiring in-country scientists that receive financial, institutional and logistical support from the EDGE programme) to determine the status of these species and identify appropriate conservation actions.
The ultimate goal of the EDGE programme is to ensure that local stakeholders, governments, and in-country and international conservation organisations take ownership of these forgotten species and commit to ensuring their future survival. To learn more about the EDGE programme as it refers to Coral Reefs got to EDGE Coral Reefs.
Pressures on Coral Reefs
Collection for the aquarium trade features as one of the many detrimental pressures on the coral reefs, fortunately the aquarium trade was at the bottom of the list but nevertheless, more and more attention is being drawn to the aquarium industry
Direct human activities are a major threat to coral reefs. Many of these threats can be small-scale or localised but they reduce the resilience of the reefs making them more susceptible to climate change and resulting diseases. The main anthropogenic pressures are:
* Over-fishing and destructive fishing practises – harvesting of fish and invertebrates beyond sustainable limits, and the use of destructive fishing methods in developing countries such as blast and cyanide fishing that destroy coral reef habitat. As human populations increase and national economies grow, there is a parallel increase in the demand for seafood. The net effect of over-fishing is that coral reefs are far more susceptible to overgrowth by macro-algae, plagues of coral predators, and probably increases in coral disease. There is also direct physical damage to the reefs from anchors, nets, traps and often devastation from the use of explosives used to stun fish. Unless fishing pressure can be significantly reduced many coral reef fisheries are likely to collapse.
* Sedimentation – sediment run-off from the land due to poor land use, development and deforestation, and benthic dredging. Sediment clouds the water column reducing light penetration, which is necessary for photosynthesis by the coral’s zooxanthellae. Sediment settling on the coral reefs can also smother corals and other sessile organisms, and increase the rates of disease and bio erosion.
* Eutrophication and chemical pollution – Most coral reefs near areas of human population suffer degradation through nutrient pollution from fertilizer run off from agricultural land, untreated sewage, animal husbandry and industry. Excess nutrients in the water encourage the growth of macro-algae, particularly when herbivores populations, mainly fish and sea urchins, are reduced, resulting in the macro-algae out-competing coral for space on the reef.
* Habitat loss from unsustainable development – Coastal development and land reclamation are increasing in many countries with coral reefs. Coastal habitats are destroyed or degraded and there are corresponding increased levels of siltation and pollution. Mining of coral reef rock and sand is also and threat in some areas.
* Coral trade: It is estimated that between 11 and 12 million pieces of live coral are traded globally each year. Included in this number are approximately 140 species of hard coral. Despite quotas and trade regulation by CITES it is unknown if these species are being harvested sustainably. The harvest of wild coral may lead to population declines and the techniques used to collect coral may cause physical damage to the reef and other species of coral that are not targeted for collection. The main exporter of live coral is Indonesia with the USA and EU the biggest importers of live coral.
Focal Species
The EDGE of Existence programme is supporting conservation projects for ten of the top EDGE coral species (see list above).
These species have been selected for conservation attention at an international workshop because they are extremely evolutionarily distinct and threatened, and are currently receiving little or no conservation attention from other organisations.
Under the above criteria I find the listing of Acropora palmata curious as it is listed under the US Endangered Species Act and has a lot of attention paid to it by various US agencies, governmental and non-governmental.
Material from the Edge website.
Comment and aquarium related analysis: Tim Hayes Midland Reefs ©2011-01-10
