Last month, the Cendrawasih Bay National Park Authority along with experts from Conservation International (CI), WWF-Indonesia, Hubbs Sea World Research Institute (HSWRI) and the State University of Papua recently completed the first expedition to tag whale sharks with radio-frequency identification (RFID) tags in Cenderwasih Bay, part in the far eastern reaches of Indonesia’s Bird’s Head Seascape – a marine area over 180,000 square kilometers in Indonesia, which Conservation International along with The Nature Conservancy and World Wildlife Fund work with government authorities, private organizations and local people to conserve the diversity and abundance of marine life and the promote human well-being.
Widely used in the U.S. for tracking pets, these tiny pill-sized transmitters are injected beneath the skin and serve as a unique, permanent “ID card” which can be scanned with a receiver wand. It will allow scientists to determine a shark’s history whenever it is next encountered.
“This technology has never been tried before with whale sharks, in large part because it‘s fairly impractical to swim after the giants with a receiver wand underwater,” said Dr. Mark Erdmann, a marine biologist who was on the expedition and is the senior advisor to CI-Indonesia’s Marine Program. “What makes this tagging possible in Cenderwasih Bay is the unique habit this population has of aggregating at bagan fishing platforms to feast upon the small silverside baitfish that the fishers are catching.”
“These massive fish can grow to nearly 50-feet, or 15 meters in length,” said Dr. Greg Stone, Chief Scientist for Oceans at Conservation International. “In order to support that massive body, they have to consume tons of plankton or small fish a day. The behavior developed by the sharks in Cenderwasih Bay is a novel, behavioral adaptation to meeting that mark.”
“The interest this video has gotten on the internet is amazing and it underscores the need for these types of expeditions to further knowledge of whale sharks,” Erdmann added. “Despite all of our technology and science, humans have very little understanding of the world’s largest fish.”
Led by Dr. Brent Stewart, senior research scientist with HSWRI, the expedition team tagged 30 individuals over five days, 29 of which were adolescent males between 3-8 meters (10-26 feet). The team is attempting to rapidly determine the size of this recently discovered whale shark population in the bay and monitor individuals’ movements in the area over the coming years.
“The bagan fishers in Cendrawasih Bay, as in most areas of Indonesia, regard the whale sharks as good luck and as friends, but overly excited whale sharks have swum into the fishers’ nets and become trapped,” Erdmann said.
“They understand the value whale sharks bring ecologically and economically in regard to the divers that come to see them in the wild. The fishers and the park authority are proactively trying to find a solution to prevent the sharks from being entangled, including possibly redesigning their nets.”