Ocean News

The return of a special white shark

8th July 2009

NutCase returns to Seal Island

We have had some spectacular days out at Seal Island in the last month. On top of our usual research activities of tagging and tracking sharks we have also being attempting to deploy Crittercams again. The deployments have been difficult so far due to a few issues with the attachment pole, but we have sorted out the problem and should be more successful from now. However, the highlight of this season so far has been the re-sighting of a very special shark called NutCuz (aka Nutcase).

On a beautiful day in 2004 we were lying on anchor and had recorded 14 different sharks at the boat that day. At about 1:30 pm the activity slowed down to nothing. However, after about 20 minutes of no shark activity we saw a dorsal fin slice the water near our boat. Immediately I noticed a distinctive natural tip on the shark’s dorsal fin which made it stand out. The shark was a 3.2 meter male. Usually white sharks are cautious when they first approach our boat and typically will make a few passes around and under the boat until they build up their confidence to approach us closer. Typically the smaller sharks may deviate from this pattern when large sharks are about and will rush the boat and bait as if they want to get out of there before the larger sharks return. This shark’s behaviour while bold and erratic at times was mixed with very relaxed states. He was determined to bite the boats motors (hard) at every opportunity and completely ignored the decoy we had floating nearby. He even stole our chum bag hanging from the side of the boat. At other times he would swim away and mouth and bump floating kelp and even stick his head out of the water and look at us. He spent over an hour making us believe he was short a few tools in his toolbox thus earning himself the name Nutcase.

Nutcase became one of our favourite sharks to see and made a huge impression on me because of the amount of time we were able to interact with him and gather insight into this individual. However, he would rarely approach the boat if other sharks were around instead waiting for a gap and then visiting the boat. We recorded Nutcase on five different occasions that year and tagged him with an acoustic pinger to monitor his movement patterns. Over the season he started spending less and less time with us. In our scientific publication on the effects of chumming on shark behaviour (Laroche et al. 2007) you can see his behaviour under SHARK 31.

In 2005 he came back to Seal Island and although his tag had come off we immediately recognised his dorsal fin and he behaved in the same mad way further earning his title. Naming sharks can seem like an unscientific approach to some people, but it actually allows for a quick and easy reference to identify animals that are fairly well known. It’s far easier to recall a name after an extended period of time than a long number, especially when you are dealing with many different animals at once. We recorded him on four different days that year. In 2006 and 2007 he came back again, but he only approached our boat one day out of each of those years. In 2008 we had no sightings of Nutcase which was very disappointing because these re-sightings yield valuable information on a scientific level and on a personal level bring you closer to the animals you spend your whole life trying to learn more about.

We are not the only boat recording the sharks at Seal Island and the shark cage diving boats that operate there do so on an almost daily basis in our winter. They also had great interactions with Nutcase, but they have named him Cuz. They didn’t record him in 2008 either. When you don’t see animals like this for a whole season you start to wonder about what may have happened to the shark. There are numerous possibilities which range from it simply being part of a natural cycle the shark follows in its life or it could be something more sinister like being caught in fisheries. Due to the difficulties in studying white sharks in most cases we never know what happens.

However, this was not the case with Nutcase. Last week we had been having a good day with about 10 different sharks recorded. Keeping tabs on the individuals needed a lot of concentration which I was focused on. We had a large foam slick from the island floating past our boat which looked like a white carpet on the water surface. One of the interns brought my attention to the fact that a shark was busy investigating some kelp in the foam. I looked up and immediately recognised Nutcase by his dorsal fin. I screamed with joy so loudly that the other boats all looked our way. He slowly approached our boat and I saw that he had grown significantly to almost 4 meters. He was now a mature male white shark. He spent a few minutes with us displaying some behaviours we knew him for, but also a little bit more caution. He was now in the big boy’s league. One of the shark operators called us to say he had seen this shark and he shared some incredible photos with us of Nutcase hunting seals which lead me to change Nutcase’s name to Nutcuz – a combination of the names we both had for this incredible shark. It was so rewarding to see Nutcuz and I hope we get more special visits from him this year.

Photo Credits: Alison Kock, Hagen Schmid, Morne Hardenberg