Winter2016AlertDiver

platforms to about 60 feet deep. Floodlights on the surface illuminate the water to

attract millions of ikan puri, three-inch-long baitfish. Fishermen raise the nets in

the morning, bringing up tons of the fish, some of which will be collected and used

as bait for bonito fishing. The rest of the baitfish remain in the net, hanging just

beneath the platform. Whale sharks in the bay have learned to suck these small

fishes from the nets. The fishermen feed bucketloads of ikan puri to the sharks,

which we now know are opportunistic feeders that can associate humans with

food. Cenderawasih Bay is the first location in the world in which such whale-shark

behavior has been documented.

On our 2015 expedition we encountered 13 individual whale sharks beneath just

one of the bagans. We started early each morning and seldom finished before dusk.

Typical of sharks, lions and humans, prime feeding times were the in the morning and

just before dusk. At 7 a.m. we usually saw two or three juveniles placidly sucking from

the net, but by 10 a.m., eight animals, ranging from 7 feet to 40 feet, would congregate

to feed from the nets or receive handouts from the fishermen. Noon was a lull period;