Today, SAMPLA launched its second major tracking effort of 2008.
With a full compliment of interns in Mossel Bay, we now have the capacity for multiple-day shark-tracking (our longest effort to date being 103 hours following one shark in 2005). With the launch of our new vessel (Cheetah), we can keep one vessel at sea whilst the other plays ferry, shuttling new crews in and out every 12 hours.
At this time of year (autumn), large seal hunting sharks usually appear in the bay. During the winter they specialise on hunting seals moving to and from Seal Island. However, nature is capricious and the last couple of weeks have brought us only sub adult sharks. Yesterday, we made a strategic decision to target a smaller shark for tracking in the Hartenbos region, the daytime resting area for the seal hunters. We hoped to plant an acoustic tag on a sub adult shark ambitious enough to attempt hunting seals.
At 8.30am, after having chummed for 20minutes, a 3 metre female turned up at the vessel – our prospective seal hunter. Prior to tagging, Courtney recorded the necessary data for the shark, including taking photographs of her dorsal fin for identification, whilst Ben lured the shark into tagging range. At 8.35 we secured the transmitter on the right side of the Zulu's (her new name) dorsal fin, and switched from chumming mode to tracking mode. The anchor was pulled up, while chum and bait were swapped for the directional hydrophone and environmental sensing instruments. Follow this blog to get updates on Zulu’s movements and behaviour every 12 hours (following change over).