ENVIRONMENTAL AND BIOLOGICAL FACTORS DRIVING WHALE SHARK DISTRIBUTION AND ABUNDANCE INSTITUTE FOR MARINE AND ANTARCTIC STUDIES 2013 NINGALOO REEF, WESTERN, AUSTRALIA R esearch W hale shark ( R hincodon t ypus)
how many of them remain. This project will help to clarify the feeding ecology of whale sharks by using very interesting biochemical techniques. The transient population on the Ningaloo Reef comprises young males between five and eight metres long. We think they come to feed on blooms of zooplankton, but our information is restricted to observations made during the day, when the sharks come to the surface. What happens the rest of the time? With this project we are trying to determine where whale sharks feed and what they eat – and, believe it or not, a small piece of whale shark can tell us! The rationale behind this is ‘you are what you eat’, as traces of food components are left in our tissue. By analysing a fragment of whale shark tissue, we can determine the animal’s diet – but first we need to collect whale shark biopsies. This is what I enjoy most about my research. To get the biopsies, a group of shark experts, plankton biologists and students head to the Ningaloo Reef every year. Once a whale shark has been located from a small aircraft, a bunch of snorkellers, each with an assigned role, jump into the water. We take photographs of the shark for identification, we tag it and we take a biopsy with a modified hand spear. An interaction with a whale shark is an overwhelming experience that you can never forget. You might have swum with them hundreds of times, but each encounter is unique and special. Young whale sharks are curious and follow your bubbles, whereas older and bigger ones sometimes don’t even notice you are there. There’s no other experience like it! 154