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Australian endangered species: Fire corals

A fire coral and friends, Millepora intricata in a lagoon on the Great Barrier Reef. Mike Emslie and Daniela Ceccarelli

Australian endangered species: Fire corals

The fire coral (Millepora boschmai) is one of the rarest species of coral in the world. It is known only from a small number of locations in the Pacific Ocean, Panama and Indonesia, and it appears this species got into hot water almost a decade before it was even known to science.

Millepora boschmai is a type of hydrocoral, related to jellyfish, anemones and the true corals that build reefs. All corals are animals, and not plants. They have bodies made of many cells without cell walls, which distinguishes them from plants and fungi. The tiny bodies of corals are hidden in a calcium skeleton, and it is the thousands of pores in Millepora skeletons that distinguish this type of coral.

This fire coral was first described from Gulf of Chiriquí, Panama in 1991. Those who described it found that there were originally hundreds of colonies but many had died from coral bleaching in warmer waters caused by the 1982-83 El Niño.

Several years later seven more colonies were found. Unfortunately, all these known colonies were killed in the 1998 El Niño. To this date there is no sign that the species has survived in Panama. With the species only known from the eastern Pacific, it was then thought to be extinct.

The mysterious Millepora boschmai collected in Indonesia. Tries Razak

Then, a study of fire corals collected from Indonesia in the National Museum of Natural History in The Netherlands revealed five specimens of M. boschmai. Collected from South Sulawesi and Sumba by Bert Hoeksema, this discovery opened up the possibility that other populations of this endangered species exist in the Indo-Pacific, and possibly Australia. It also reinforces the value of museum collections for global change studies.

Status

Globally, Millepora boschmai is Critically Endangered and the only remaining populations occur in Indonesia. The status of Millepora boschmai in Australia is unknown and currently there are no records of it occurring in Australian waters.

There are another 14 species of_ Millepora_ known to exist worldwide. Two of these species are listed by the IUCN as Endangered and two are listed as Data Deficient. Numerous Millepora species are restricted to the Atlantic Ocean however six species are known to occur in Australia (M. dischotoma, M. exaesa, M. foveolata, M. intricata, M. platyphylla, and M. tenera).

The distinctive pores of Millepora boschmai, which distinguish it from reef-building corals. Tries Razak

In Australia, Millepora species occur in a variety of habitats to at least 30 metres deep. They can be found in inshore areas such as the Kimberley coastal reefs, and also in the clear waters offshore. Some of these species are found abundance. M. intricata, for example, is a dominant species in the Lizard Island lagoon on the Great Barrier Reef.

Nevertheless, the exact status of all Millepora species in Australia is unknown and further research is needed to identify species and population status.

Threats

The major threat to fire corals is climate change, in particular the temperatures extremes that lead to bleaching events. Fire corals are often among the first to bleach after warming events, however they can also respond quickly after disturbance and re-establish.

This genus is generally not found in the aquarium trade, but is sometimes collected for curio and jewellery trade. Crown-of-thorns Starfish are a major threat to corals in Australia, but according to observations in Fiji, Millepora is not a target.

Not only are fire corals threatened by warming but also pollution and habitat loss. Nobody yet knows the combined effect of these threats.

The fire coral Millepora platyphyllia growing in the Marshall Islands. Maria Beger

Strategy

Fire corals are listed under Appendix I and II of CITES, which regulates the trade of endangered species. Including these types of coral on the CITES list is important to preserving them and for developing fisheries management strategies.

Captive breeding and techniques such as cryo-preservation should also be looked at to conserve coral biodiversity in the future.

Parts of the distributions of several Millepora species fall within Australian Marine Protected Areas and it is likely they will benefit from those reserves. Nevertheless, recommended measures for conserving this species include research in taxonomy, population, abundance and trends, ecology and habitat status.

Conclusion

Preventing coral reef degradation and biodiversity loss is the key goal of marine management. Coral deaths capture most of the attention while the fate of other reef animals like fire corals has been ignored.

To ensure the survival of fire coral in Australia, ongoing monitoring and research programs are needed with further restrictions on collection and trade of corals. Coral reefs are sensitive habitats that must be protected from runoff and coastal development to ensure these globally important ecosystems survive and thrive in the future.

The Conversation is running a series on Australian endangered species. See it here