Posted on Tuesday, 31 August 2004
Greetings from Seal Island! We have had a good shark month but can definitely feel that the season is winding down. Predatory activity has still been high and we have been seeing about 6 to 12 events daily. I am thinking to myself that this is actually quite low after what we have seen this season but looking back at our records this is normal. It is just that this season has been so phenomenal!
While I am on the subject of predatory events I want to write about a particularly interesting interaction that we observed. After seeing an event in progress we arrived to find that the shark had made a successful kill and was feeding on the seal carcass. Within 30 seconds another two sharks were at the predation site and they were extremely excited. They were not openly aggressive to one another, but were moving very rapidly around and through the predation area. By this time the seal carcass was consumed by the shark that had made the kill. 95% of the time we have noted that the seal carcass is consumed within minutes and we believe this has to do with firstly the prey size. The number 2 seals that are usually preyed upon are in the 25 to 30kg range. Secondly, there are usually quite a few sharks in the area so there is a lot of competition to finish off the meal before a larger shark takes over.
The three sharks stayed in the area for a further 5 minutes and all went quiet.
Another 5 minutes later we were drifting near the area when I noticed two Number2 seals making their way back to the Launch Pad. They were passing over the exact area where the last predation had taken place and just as I thought something was about to happen, a shark breached clear out of the water and in the process successfully caught one of the seals. When we approached closer we were able to identify the shark as one of the sharks that had arrived at the earlier predation.
Chris has for many years believed that, purely from our observations, white sharks move in loosely associated groups. We often will identify the same sharks together at Seal Island. For instance, every time we saw “Scratchy” this year, we also saw “Shy”. There are also two sharks that we have seen at predatory events this year that both have very distinctive marks and tags. One is about 3,8 meters and the other is about 3,4 meters. We have not had good sighting of them around our boat when anchored, but on three different days this year we have seen them make successful kills on the same day. There are many of these cases and another interesting point is that when numerous predations occur they will most often happen in spates. For instance, we won’t see anything for half an hour and then suddenly there will be four events in five minutes. We definitely believe that each white shark in the area is aware of what the others are doing, and who knows, maybe even sometimes they excite one another to hunt?
In early July this year Rob had just put his anchor down when four sharks arrived together. They seemed completely at ease with one another (which is unusual!) and as quickly as they arrived, they departed. One of Rob’s clients, Rafa , was so impressed by this lot that he dubbed them “The Wolf Pack”! This was all speculated in jest but maybe one day we will find out that he was not too far off…
Again this month we have struggled to get sharks up to the boat when anchored but we have identified “Schumi” and “Wonky Tail”. We also had a sad case of a very small shark of just less than two meters in length that had a trace out of the corner of her mouth. She had also been tagged with something that had broken off ,probably a camera or telemetric tag, and on the tether there was a large amount of growth that included red bait and barnacles. This big, messy lump was continually cutting into her back which produced a large open wound. Fortunately we were able to get her close up to our boat and Chris pulled on the tether. He was unable to pull the whole thing off, but managed to remove the growth which will hopefully give the shark some relief. We were very angry, and upset, to see what had happened to this shark. No matter what good intentions people may have, human impact can have disastrous effects. For the first time this season we have had a very big problem with recreational boats (that definitely do not have a permit to work with white sharks) coming to Seal Island and chasing predatory events. As the white shark is a protected species the law says that no one may attempt to attract or disturb a white shark in any way unless they have a permit to do so. Encroaching on a predatory event is disturbing a white shark. When we have tried to tell these people, in a nice manner, that they are not allowed to interact with white sharks we have been met in some cases with abusive language and other times completely ignored. The authorities are aware of the situation and the perpetrators are under investigation.
On a lighter note, we have been having some fun with a tow-cam. When film crews come out they are always looking for interesting and different angles to film the sharks. An Italian camera man friend of ours spent a few days on the boat with us and he made use of an underwater torpedo camera. Once the predatory activity had cooled down we towed this camera around the Island. The sharks are extremely curious about this camera and once they pick up on it they spend quite a while swimming behind it trying to figure out what it is and I suppose, if they can eat it or not!
On one occasion we drove past Rob’s boat and picked up a shark that was around his boat. The shark followed us for a good ten minutes and eventually, feeling rather guilty at having “stolen” the shark from Rob, we brought it back to him. The shark duly obliged and both parties were happy!
Our friend had a clam shell screen on board and we could watch what the camera was picking up, so could clearly see when a shark was following. Another shark was playing the game very nicely and we decided to try bringing him over a shallower area for a pretty background. Well, as soon as it became a little too shallow the shark decided that this definitely was not for him and he bolted out of screen not to be seen again as he returned to his comfort zone!
From the past years we know that September will probably be our last month of large numbers of white sharks. Usually what happens is that our summer wind, the South Easter starts to blow, bringing the warmer water and summer fish species with it. We have already had a lot of South east wind and geelbek, which is a summer fish, is already being caught a few hundred kilometers from Cape Town which means they are on their way here. Hopefully I will have some white shark news for everybody next month!
We are already planning our off season shark adventures and I must say we are very excited about seeing mako and blue sharks again.
Last year in March we put together a “Sharks of Southern Africa” expedition. We usually would do this 14 day trip on our own but last year decided to open it up to guests for the first time. We had a very successful trip and saw and dived with ten different shark species in ten days. These included great whites, mako’s, bronze whalers (copper sharks), smooth hammerheads, ragged tooth’s and a variety of small endemic cat sharks. We were very unlucky not to see blue sharks and will hopefully achieve this next year, as well as spotted seven gill cow sharks which we have found in a new spot since this last expedition.
This expedition is a great opportunity to see a variety of sharks in a short space of time. Half of the expedition is also run in a magnificent area that is fantastic for bird watching, hiking and tag and release fishing , the other half of the expedition is run from Simonstown, 35minutes from Cape Town.
We will be running the expedition in mid March 2005 and have limited the number of people per expedition to 6. If anyone is interested in receiving more info on this adventure please email us by replying to this month’s newsletter. We do get many emails from readers wanting to join us one day and we hope that this will be a great opportunity for you all!
Until next month,