Author : Nita Yohana, Published : http://www.conservation.org
Whale shark under bagan (fishing platform) in Indonesia. (© Burt Jones and Maurine Shimlock)
In late 2011, CI’s Mark Erdmann blogged about an exciting expedition tagging whale sharks in Cenderawasih Bay off the northern coast of West Papua, Indonesia. The trip was conducted in collaboration with WWF-Indonesia, Hubbs-SeaWorld Research Institute and the Cenderawasih National Park Authority. Data received from the tags exposed the migratory behavior of these mysterious creatures along Indonesia’s coasts.
In Kaimana, on West Papua’s southern coast, the recent discovery of another whale shark population has triggered similar research, providing us with vital information backing the development of critical regulations to protect these species and support a burgeoning whale shark tourism industry that is both sustainable and benefits local communities.
Whale sharks are the largest living fish species, growing up to 18 meters (60 feet) and weighing 20 tons, yet they are known for being among the most gentle of the shark species. With enormous mouths that can be up to 1.5 meters (4.9 feet) wide, these filter feeders’ diet predominantly consists of plankton and small fish like anchovies.
Fishermen on Papua’s coast have long been aware of the existence of these animals. In fact, the sharks frequently approach the bagan (fishing platforms) where the fishers pull up nets of baitfish, hanging around for an easy meal or sometimes sucking fish from holes in the nets
Many fishermen consider the sharks to be good luck. And with an influx of tourists pouring into communities to see the sharks’ feeding activity in person, protecting whale shark populations will be the smartest economic choice for these communities.
Whale shark tourism has been thriving in Cenderawasih Bay since 2010. Yet in Kaimana, the region’s tourism potential is only beginning to be realized.
Kaimana is located in West Papua’s Bird’s Head Seascape, recognized as the global epicenter of marine biodiversity. Since 2011, domestic and foreign tourists in Kaimana have increased, yet the region still lacks infrastructure that could make it a more accessible and popular destination.
While encouraging tourism, it’s also critical to protect the whale sharks from negative impacts resulting from human interaction. The more we know about the behavior of whale sharks, the better we can help local communities value and protect them.
Up to this point, our understanding of the life cycle of whale sharks remains limited. We know that whale sharks are normally solitary and frequently spend a fair proportion of their time in depths below 100 meters (328 feet).
We also know that they are able to migrate great distances to take advantage of seasonally abundant food sources, around which they tend to briefly gather in large numbers to feed before dispersing again). Most of the sharks observed in these aggregations are young males in the 4-8 meter (13-26 foot) size range — but we don’t know much else. This is why we are conducting this research in Kaimana.
Since December 2013, CI has photo identified 11, satellite tagged four and genetically sampled six whale sharks in Kaimana. The satellite tags record depth, temperature, and light level data (used to estimate location) of the shark’s diving behavior over a certain period of time. The time frame of deployment of these tags varies; some have been programmed to pop off the shark after three months, while other stay on for six.
Every whale shark has a unique spotting pattern on the body, similar to a human’s fingerprint. By taking photo IDs of each individual (the left side of the animal between the gills and the dorsal fin), we hope to learn whether any of the sharks observed in Kaimana are the same ones seen in Cenderawasih Bay.
Fishermen feeding whale shark off of bagan fishing platform. (© Conservation International/photo by Nita Yohana)
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