Tuesday, August 26, 2008

Shark Chronicles 025 - Night Time Hunting


For one of the first times since “Sharkville” was released, SAMPLA crew members were able to witness a night time predation of a white shark on a seal near Seal Island. The predation was observed during a twenty four hour seal survey taking place on August 14 through 15, 2008. SAMPLA crew members aboard the vessel Cheetah began the survey at approximately 6pm. After anchoring, Christine, Ryan, Adam, Amy, Viola, and Ed began the night by placing a seal decoy in the water in hopes that a shark would breach while the crew waited patiently for seals to begin moving from the island. As the SAMPLA team waited, a group of approximately 6 seals began to move quickly toward the boat just before sunset. A few meters from the boat, the group of seals suddenly split and began to porpoise high out of the water. Intently watching with hopes of a shark predation, we were pleased to see a white shark breach on one of the smaller juvenile seals in the group. The predation was unsuccessful in killing the seal, which then quickly swam back to the safety of the island. Minutes later, the sun set behind the hills and it became true night.



The overcast sky hid the moon, but seal movements were still able to be seen with the help of night vision binoculars and the lights of Mossel Bay. For the first few hours many seals were seen moving to and from the island, but no other shark predations were observed. Suddenly at approximately 10:30pm, a large splash was heard a few hundred meters from the boat. Ryan spotted the splash and the SAMPLA crew watched anxiously to see if it was what they had been waiting for, a white shark night predation. The darkness made it hard to see what animal had in fact made the splash, but it was evident that a chase was occurring between predator and prey. The chase continued for a minute or so, and visual clues pointed to a white shark predation on a seal. Abruptly the shark appeared to grab hold of the prey and violent thrashing began at the surface of the water. In the darkness the SAMPLA crew was unable to see if the predation was successful or not, but splashing subsided soon after the predation.



Witnessing a night predation of a white shark on a Cape Fur Seal in Mossel Bay is a unique and amazing experience. Those who were aboard Cheetah during the third 24-hour seal survey were lucky enough to see this phenomenon in person! Observing the unique night time predatory behavior of white sharks in Mossel Bay was a thrilling experience for all the SAMPLA members on board Cheetah that night.-


Christine Moore (SAMPLA intern)

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