New Sharks, Rays Discovered in Indonesia Fish Markets
for National Geographic News
|March 1, 2007|
At least 20 previously unknown species of sharks and rays have been
found during a survey of local fish markets in Indonesia,
The five-year study focused on catches from tropical seas around the Southeast Asian country, which encompasses more than 17,000 islands (Indonesia map).
So far six of the new species have been described in scientific journals. These include the Bali catshark, the Jimbaran shovelnose ray, and the Hortle's whipray (see photos of some of the species found during the survey).
Scientists are preparing to describe a further 14 of the species.
In total more than 130 species were sampled between 2001 and 2006 at 11 ports across Indonesia.
The Australian-led team behind the study says their work will provide the first ever detailed description of Indonesia's sharks and rays, including information critical to the marine animals' conservation.
Indonesia has the most diverse ray and shark fauna in the world, said study co-author William White, of the marine research division of Australia's Commonwealth Scientific and Industrial Research Organization (CSIRO) based in Hobart, Tasmania.
The island region also has the world's largest shark and ray fishery, White said, with reported landings of more than 110,000 tons (100,000 metric tons) a year.
"Good taxonomic information is critical to managing shark and ray species, which reproduce relatively slowly and are extremely vulnerable to overfishing," White said in statement.
"Before this survey, however, there were vast gaps in our knowledge of sharks and rays in this region."
In addition to cataloging new species, the Australian team's data will be used for estimating population sizes, assessing the impacts of fishing, and developing conservation measures for at-risk species.
Sarah Fowler is co-chair of the shark specialist group for the nonprofit World Conservation Union (IUCN).
Fowler said the survey is a "really important start toward the process of providing names for these animals and starting to draw people's attention to the fact they could be threatened almost before they are described."
More than 800 specimens collected during the fish market trawls are now lodged at the Museum Zoologicum Bogoriense on the Indonesian island of Java and at the Australian National Fish Collection in Hobart.
The survey also forms the basis of a new field guide called Economically Important Sharks and Rays of Indonesia that is available in English and Indonesian.
The guide represents the first in-depth report of Indonesia's sharks and rays since Dutch scientist Pieter Bleeker described more than 1,100 new fish species between 1842 and 1860, the survey team said.
At the time scientists in Europe rejected Bleeker's finds, saying they doubted such high levels of diversity could exist among marine life.
However, many of the species Bleeker described were rediscovered more than a century later in fish markets in Jakarta in the mid-1990s.
New Species Bonanza
Indonesia, the world's most extensive archipelago, is thought to have the highest diversity of native marine wildlife in the world.
A recent expedition to the seas of West Papua led by the nonprofit Conservation International turned up some 50 previously unknown species, including sharks that "walk" along coral reefs on their fins.
(See photos of the "walking" shark and other new species found during the 2006 expedition.)
"It's extraordinary—for large animals like this—just how many new species are being discovered," IUCN's Fowler said.
She noted, however, that in nearby Australia more than 30 percent of sharks and rays are found nowhere else.
"So it's not a surprise that as people go through the markets in Indonesia that they find these new species," she said.
Many of the smaller sharks living in the waters around Indonesia are not found elsewhere, she added, because they are not good swimmers.
The main threat to such populations comes from small, intensive coastal fisheries and subsistence fisheries.
Together, she said, both fishing practices "take very, very large quantities of sharks and rays."
Free Email News Updates
Best Online Newsletter, 2006 Codie Awards
Sign up for our Inside National Geographic newsletter. Every two weeks we'll send you our top stories and pictures (see sample).
|© 1996-2008 National Geographic Society. All rights reserved.|