Floreana coral  (Tubastraea floreana)

Classified as Critically Endangered (CR) on the IUCN Red List 2007 (1) and listed on Appendix II of CITES (2).

An uncommon species of the Galápagos, Floreana coral is a scleractinian coral, meaning that it is a ‘hard’ coral with a limestone skeleton (3). The polyps of Floreana coral are bright pink in the water, and dark red-black when dry (4).

Found only in the Galápagos, this rare coral species was once known from around the islands of Floreana, Isabela, Pinzón and Santiago, and the islets of Gardner and Cousins (1). However, since 1983, the Floreana coral has only been sighted at Cousins Rocks and Gardner Islet (1).

Floreana coral can be found on the ceilings of caves, ledges and overhanging rocks, between depths of 2 and 46 metres (1).

Floreana coral is an azooxanthellate coral, meaning that this species does not have zooxanthellae, the algae that live inside the tissues of some corals and provide the coral with food (3). Corals without zooxanthellae instead feed on zooplankton, capturing these tiny aquatic animals in their outstretched tentacles (5).

Thought to once have been fairly widespread around the Galápagos Islands, since the El Niño event of 1982-83, this coral has only been found at Cousins Rocks and Gardner Islet, and despite searches specifically for this species, Floreana coral has not been seen at Cousins Rocks since 2001 (1). This suggests that Floreana coral populations suffered mortalities as a result of the El Niño event, and it is therefore likely that any other alterations to the water temperatures surrounding the Galápagos Islands, such as global climate change, will also threaten this coral (1).

The unique biodiversity of the Galápagos Islands and the surrounding waters is recognised and valued, and thus the region is protected by being designated a Marine Reserve and World Heritage Site (1). Floreana coral is also included in Appendix II of the Convention on International Trade in Endangered Species (CITES), meaning that any international trade in this species should be carefully regulated (2). Unfortunately, neither of these measures protects this Critically Endangered coral from the threats of natural, or man-induced, climate change.

For further information on conservation in the Galápagos see:

• Charles Darwin Foundation:
  www.darwinfoundation.org

• El Niño: a natural phenomenon that happens every 4 to 12 years, and lasts for several months, when upwelling of cold, nutrient-rich water does not occur. This causes the warming of ocean surface water off the western coast of South America and causes die-offs of plankton and fish. It also affects Pacific jet stream winds, altering storm tracks and creating unusual weather patterns in various parts of the world.
• Polyps: the typically sedentary soft-bodied components of cnidaria, a group of simple aquatic animals including the sea anemones, corals and jellyfish. Each polyp comprises a trunk that is fixed at the base, and a mouth that is placed at the opposite end of the trunk and is surrounded by tentacles.
• Zooplankton: Tiny aquatic animals that drift with currents or swim weakly in water.

1. IUCN Red List (September, 2007)
   http://www.iucnredlist.org
2. CITES (July, 2008)
   http://www.cites.org
3. Veron, J. (2000) Corals of the World.Australian Institute of Marine Science, Townsville, Australia.
4. Glynn, P.W. and Wellington, G.M. (1983) Corals and Coral Reefs of the Galapagos Islands.University of California Press, Berkeley and Los Angeles, California.
5. Barnes, R.D. (1987) Invertebrate Zoology. Fifth Edition.Saunders College Publishing, US.