Hundreds of new species of coral and other species discovered on Great Barrier Reef
26/09/2008 17:23:41
One of hundreds of soft corals found on CReefs expedition, 2008. Credit CReefs.
September 2008. Hundreds of new species surprised international researchers systematically exploring waters off two islands on the Great Barrier Reef and a reef off northwestern Australia, waters long familiar to divers and biologists.
The expeditions, affiliated with the global Census of Marine Life, help mark the International Year of the Reef and included the first systematic scientific inventory of spectacular soft corals, named octocorals for the eight tentacles that fringe each polyp.
The explorers have released some initial results and stunning images from their landmark four-year effort to record the diversity of life in and around Australia's renowned reefs.
Discoveries at Lizard and Heron Islands (both part of the Great Barrier Reef), and Ningaloo Reef in northwestern Australia, included:
• About 300 soft coral species, up to half of them thought to be new to science;
• Dozens of small crustacean species -- and potentially one or more families of species thought to be unknown to science;
• A rarely sampled amphipod of the family Maxillipiidae, featuring a bizarre whip-like back leg about three times the size of its body. Only a few species are recorded worldwide;
• New species of tanaid crustaceans, shrimp-like animals, some with claws longer than their bodies;
• The beautiful, rare Cassiopeia jellyfish, photographed upside down on the ocean floor, tentacles waving in the water column -- a posture that enables symbiotic algae living in its tentacles to capture sunlight for photosynthesis;
• Scores of tiny amphipod crustaceans - insects of the marine world - of which an estimated 40 to 60% will be formally described for the first time.
As well, the researchers deployed new methods designed to help standardize measurement of the health, diversity and biological makeup of coral reefs worldwide and enhance comparisons.
Species of sea urchin found during the CReefs expedition, Australia, 2008. Credit CReefs
Preparing for future discoveries, the divers pegged several layered plastic structures - likened to empty doll houses - for marine life to colonize on the ocean floor at Lizard and Heron Islands. Creatures that move into these Autonomous Reef Monitoring Structures (ARMS), which provide shelter designed to appeal to a variety of sea life, will be collected over the next one to three years.
"Corals face threats ranging from ocean acidification, pollution, and warming to overfishing and starfish outbreaks," says Dr. Ian Poiner, Chief Executive Officer of the Australian Institute of Marine Science (AIMS), which led the research. "Only by establishing a baseline of biodiversity and following through with later censuses can people know the impact of those threats and find clues to mitigate them."
Difference in colonisation
Previous studies have uncovered large differences in the biodiversity at the Great Barrier Reef's Lizard Island and, further south, Heron Island - 30% more hard corals, 40% more fishes, for example. The cause of such gradients in species diversity is poorly understood, but species richness in the region tends to decrease with distance from the equator. Ningaloo Reef appears to be the least biodiverse of the three sites studied, which may be related to its comparative isolation from other reef systems.
Understanding these biodiversity gradients and the influence of connectivity will help scientists predict reef biodiversity worldwide. Expeditions to the same three sites will be repeated annually over the next three years to continue their inventory and measure impacts of climate change and other processes over time.
First systematic inventory of soft corals on Barrier Reef
The expedition marks the first census of soft corals, named octocorals for the eight tentacles that fringe each polyp. Researchers believe between one-third to half of the hundreds of soft corals found are species new to science. While the colorful animals are not reef builders, they dominate some areas studied, covering up to 25 per cent of the ocean floor. They also provide important habitat for other species.
150 new species of coral
The addition of perhaps as many as 150 new species to the global inventory of soft corals is a major addition to the knowledge of this group which, despite its high distribution worldwide, remains one of the most poorly understood groups.
Despite the large number of new species already discovered, Dr. Caley believes as many new species again may be found on future expeditions. DNA barcoding will dramatically expedite the identification of these species in future, he adds.
The Census of Marine Life (www.coml.org ) is a global network of researchers in more than 80 nations engaged in a 10-year initiative to assess and explain the diversity, distribution, and abundance of marine life in the oceans - past, present, and future. The network will release the first Census of Marine Life in 2010.
CoML Census of Coral Reef Ecosystems (www.creefs.org )
