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In Indonesia, Biologist Discovers Second Population of Primitive Coelacanths by Robert Sanders, Public
Affairs
The startling find by Berkeley postdoctoral fellow Mark Erdmann comes nearly 60 years after a living coelacanth (pronounced "SEE-la-kanth") was first discovered, surprising paleontologists who had assumed the fish became extinct 65 million years ago. The 1938 find ignited a worldwide fascination with the so-called "living fossil," and led to numerous expeditions to capture a live coelacanth. Since then more than 100 ceolacanths, now protected as an endangered species, have been taken within a 100-mile stretch of the Indian Ocean between Mozambique and Madagascar. Aside from three strays captured not far away, none have been found elsewhere. Erdmann's discovery of a second population of ceolacanths was reported in a brief letter in the Sept. 24, 1998, issue of Nature, co-authored by Erdmann; Roy Caldwell, professor and chair of integrative biology; and M. Kasim Moosa of the Indonesian Institute of Sciences in Jakarta. Indonesian President Bacharuddin Jusuf Habibie announced the find to the Indonesian people at a 1998 International Year of the Ocean festival held in Manado, Sulawesi, Sept. 26. The new population of Indonesian coelacanth seems centered around the island of Manado Tua in North Sulawesi. Because of its beautiful coral reefs the island is a popular diving spot. The first coelacanth, with its distinctive lobed fins, was sighted a year ago in a fish market in Manado, on the Sulawesi mainland, by Erdmann and his wife Arnaz Mehta, who had just celebrated their honeymoon. They have lived for the past seven years in Indonesia, where Erdmann studies the health of Indonesia's coral reefs. Mehta is a nature guide. Unable to purchase and transport the 50-pound fish, Erdmann later returned to Manado in search of a second coelacanth. This time he had financial support from the National Geographic Society to interview Indonesian fishermen and observe and photograph their fishing practices. On July 30, 1998, local fishermen caught another coelacanth in the waters off Manado Tua and brought it to Erdmann's home. Amazingly, for more than three hours Erdmann was able to photograph the live fish swimming with local people and with his wife before the fish died. He then froze the coelacanth, which weighed 64 pounds and measured four feet in length, and subsequently presented it to Indonesian scientists for safe keeping. "The biogeographic importance (of this find) is enormous," Erdmann said. "It seems highly unlikely that this fish only occurs in two highly disjunct populations -- the Comoros and Sulawesi -- separated by more than 6,000 miles. Rather, it is quite possible that the living coelacanth exists in the vast intervening ocean area between Sulawesi and the Comoros. "Even if the Sulawesi population is the only other area where the coelacanth is found, the fact that it could escape detection from the scientific community in an area well-studied by ichthyologists for over 100 years is wonderful. It is a humbling and exciting reminder," he said, "that humans have by no means conquered the oceans, and provides fodder for our imagination about other, as-yet-undiscovered 'sea monsters' and oddities from the deep. And it underscores the importance of protecting our oceans, lest we lose things forever which we have not yet even discovered!" "One of the basic questions we want to answer is, how closely related are the Indonesian and African species?" said Caldwell, who was Erdmann's doctoral advisor. "They could be one megapopulation, or they could have been separated for millions of years." With the permission of the Indonesian government, Erdmann and Caldwell hope to find another coelacanth from which to obtain tissue samples to bring back to Berkeley for genetic analysis to determine how recently the two populations were in contact. The primitive fish was once thought to be a direct ancestor of humans, with biologists picturing the fish long ago using its fleshy pectoral fins to walk out of the water. Today it is known that the equally primitive lungfish is a more direct human ancestor, while the coelacanth probably was an evolutionary dead end. Like the Comoran coelacanth, the Indonesian coelacanth occurs in an area of active volcanic islands with many caves and crevices at a depth of from 500 to 650 feet. Based on what is known of the Comoran coelacanth, the Indonesian coelacanths probably spend the day inside these caves and come out at night to forage down to about 1,640 feet along the gently sloping volcanic flanks of the islands. Based on conversations Erdmann had with local fishermen, the Indonesians do not eat coelacanths. However, when the fish on rare occasions turn up in deep-sea nets set for sharks and oilfish, local fishermen try to sell them to unsuspecting marketgoers. Erdmann and Caldwell suspect that few coelacanths are caught in the area because most local fishermen set shallow nets for tuna and more valuable fish. Only traditional fishermen go to the trouble of setting the unwieldy gill nets, which are around 500 feet long and 36 feet deep, in search of deep sea fish. The scientists are very concerned about the fate of the new coelacanth population. In the 60 years since the Comoran fish was discovered, the population of around 500 has dwindled to perhaps fewer than 200, despite government prohibitions on catching them and a ban on international trade established by the Convention on International Trade in Endangered Species (CITES). With attention now drawn to the Indonesian coelacanth, illegal fishing could threaten this population as well. "While the CITES Appendix 1 status of this fish theoretically provides it protection from international trade, the fact is that none of the relevant authorities -- especially customs and fisheries inspection officers -- in Indonesia even know of the existence of this fish," Erdmann said. "The wheels have been set in motion to quickly educate the relevant authorities, and I am confident that the Indonesian government is taking coelacanth conservation issues quite seriously. The Indonesian Institute of Sciences is now preparing to direct further research efforts on Indonesian coelacanths." The Comoran coelacanth was discovered in 1938 by Marjorie Courtenay Latimer, the curator of a tiny museum in the port town of East London, northeast of Cape Town, South Africa. At the time dubbed the "most important zoological find of the century," it quickly became a holy grail for museums around the world. Coelacanth skeletons litter the fossil record starting about 410 million years ago, but after the fish's heyday some 250 million years ago, its fossils slowly dwindle. The presumption was that the fish died out. "They appeared to go extinct with the dinosaurs at the end of the Cretaceous period, because no fossils have been found after 65 million years ago," Caldwell said. Despite numerous expeditions to find a second coelacanth, it wasn't until 1952 that another was caught in the Comoros. Since then, most have been caught among these islands, and it is thought that the original fish from the Indian Ocean was a stray from the Comoran population. No one has been able to keep a coelacanth alive in captivity. Before the discovery of the coelacanth, Erdmann had been studying stomatopods or mantis shrimp as possible bioindicators, attempting to use ecological information about stomatopods to influence protection of coral reefs from marine pollution. "The coelacanth has an equally fascinating natural history, and because of its widespread appeal, has great potential as a keystone species to influence marine conservation development in Indonesia," he said. "As such, I look forward to continuing both research avenues, with the ultimate aim of securing the future of Indonesia's reefs, the most magnificent and highly threatened in the world." Support for this work came from the National Geographic
Society and a National Science Foundation International
Postdoctoral Fellowship with the Indonesian Institute of
Sciences.
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This site is produced and maintained by
the Office of Public Affairs, University of California,
Berkeley. |
A
primitive fish previously known only from a small area
around the Comoro Islands off the coast of Africa, has been
discovered at a new site 6,000 miles away in the waters off
northern Sulawesi, Indonesia.
