Marine biologist Amanda Hay is on beautiful Lizard Island where she is conducting research into behaviour of larval fishes. Today, she writes about her encounter with a large shark.

I had intended writing about the equipment we are using to study our larval fish (the DISC is a very impressive piece of equipment), but sometimes there are more exciting things to write about. Lollygagging out and about in blue water can throw up some remarkable surprises.

Jack and Amanda
Jack and Amanda Image: Amanda Hay
© Australian Museum

Each day we have been spending between 5 and 7 hours in the tinny, most of the time we are about 1 kilometre off Watsons Bay. Needless to say we can get hot and bored so we sometimes jump in the water to cool off and have a swim.

From about 4pm in the afternoon we had been seeing a lot of baitfish action, which can be quite spectacular. Bubbling water, Mackerels (not sure which species) jumping out of the water and Terns plunging in for a feed. On one occasion, Jack and I put on our diving masks and swam over to the action. It was quite beautiful. Huge numbers of Herrings (Clupeidae) schooling around us, mouths gaping wide feeding on plankton. We were really surprised however, when what should follow the Herring up from the depths but a Shark.

My initial thought was "This is awesome", then I shrieked loudly to make sure Jack had also seen the shark. It then dawned on me that we were in the open ocean in the middle of a school of little fish that get eaten by bigger fish (yes, I am a trained biologist). The Shark was about 2 metres long and was most likely a Grey Reef Shark, Carcharhinus amblyrhynchos or a was possibly a Bull Shark, Carcharhinus leucas. It checked us out then quickly dropped out of sight. As soon as he disappeared, Jack and I swam the 30 metres back to the boat rather quickly. Unfortunately it was the only swim on which I didn’t take the underwater camera!

We all know that swimming in the late afternoon surrounded by a school of little fish is probably entering the 'shark danger zone', but I would do it all again to see the majesty of such a spectacular fish in its natural environment.