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PERFORMANCE INDICATORS
4C Management by Objectives

Fantastic trip today! We anchored in Joubertsdam and saw four separate sharks with all divers getting viewings from the cage. One shark was a resight a 2.8m female with a hole in her dorsal fin from a satellite tag, an extremely active animal.

We then proceeded to Dyer Island where we witnessed the most amazing shark activity. In the space of ten minutes we observed two sharks in the channel cruising around looking for seal pups to take. As we watched the seals playing about nervously one of our new Marine Dynamics volunteers Tami Kaschke said "I'd love to see a seal pup get taken..." Before she could finish a shark was in the air with a seal pup in its mouth - our very first predation of the year and what better place than in Shark Alley itself. What an amazing trip.

Photography and text by Alison Towner, Marine Dynamics

(Marine Dynamics donated R20 000 towards this expedition, which also involved Marine Dynamics Marine Biologist Allison Tower.)

The purpose of the expedition was to determine whether reports of Zambezi (bull) sharks in the Breede River could be confirmed. Scientifically, confirmed reports would be extremely relevant on a global scale as this would represent the most south-westerly distribution of bull sharks in Africa.

Joining us on the expedition was Dr. Steve Lamberth and his team from MCM, Hennie Papenfuss from Big Fish Safari and a team of four from SASC. We fished for 3 days with no luck & were rewarded on the 4th day when Hennie caught a bull shark on his line. After an hour and a half struggle with the fish (during which it towed him 2.5km further upstream), Hennie managed to tire her enough to bring her close to shore for landing. Our team then brought her carefully to the shore, where we were able to collect all the required data.

We measured her, tagged her with two acoustic tags (one continuous and one coded) and one spaghetti tag, and gathered genetic samples in order to determine whether bull sharks in the Breede River represent a distinct population from those found elsewhere in South Africa.

She is a world-record breaking shark measuring 4 metres total length, weighing in the vicinity of 550-600kg. This is the largest bull shark known to science - the previous maximum size was thought to be 3.4-3.5 metres TL. We also suspect she was pregnant and may very well be using the Breede as a pupping ground.

Following the tagging, we proceeded to track her for 43 continuous hours. She spent the majority of the time in the estuary, with only a few hours in the surf zone just outside the river mouth. Her behaviour during the 43 hours was fascinating and I will be writing a detailed report following the analysis of telemetry data.

To speak quite frankly, it was the most incredible experience of my life and I am so excited about the research we will continue to do. One of the major problems is acquiring the funding to continue the research, as it is vitally important we return to the Breede within the next 2 weeks to continue tracking her. Provided we can secure the necessary funds, we will embark on a second expedition to continue the tracking and gain a better understanding of her movements in the estuary.

Meaghen McCord