July 2004 Shark Bytes
Posted on Saturday, 31 July 2004
Dear Shark Lovers!
We have had yet another month of incredible great white shark hunting behaviour at Seal Island and it has just taken me quite a while to go through all our information that we recorded on what we observed. We have seen a higher number of predatory events than in previous years and this July we recorded a total of 364 events. Of those the sharks were successful on 280 occasions (76.9%). This is much higher than usual, with the average being at just under 50%. We will most probably find that it will even out by the end of the season.
We recorded three days of more than 30 events and on one day we recorded a massive 45 events. This is far higher than what we ever expected to see in one day. A lot of the attacks were occurring far off from the Island making it extremely difficult due to a strong Southeast wind that was blowing. This meant that we had to many times plough the boat head-on into the sea, with everyone hanging on for dear life as we gained some serious airtime! When one witnesses so many events it is very difficult to comprehend what we are actually seeing. Everything is happening so fast and often there are multiple attacks going on at the same time. Intense predatory behaviour such as this is definitely not normal, and this is what makes Seal Island a very unique and special spot on earth.
It is imperative that at each predatory event the animals concerned are treated with complete respect and that the person driving the vessel always puts the sharks and seals first. We have a very strict policy that we follow in each predatory event whereby the vessel is put in a position that allows it to be manoeuvred with maximum ease and the least amount of actual engagement of the engines. We are also very careful as to never block the escape route of the seal or attack path of the sharks. These practices have taken us years to develop and it is only after watching thousands of predatory events that you actually realise how small things can interfere with the outcome of each event. In South Africa it is actually illegal to disturb Great Whites without a permit whether you are baiting them or not and fortunately those that have permits in the Seal Island area have been there for many years and try their very best so as not to impact negatively on predatory events that can so easily be disturbed.
We have been very lucky in that most of the time the weather has been great with very little wind and cloud cover. This goes a long way in identifying a shark at a predatory event. This has been one of the most fascinating aspects for me this season as we have made some very interesting observations. We did not have a very clear idea of how often each shark fed but we had observed Black-white-black a few years ago make three successful predations in ten days. This was three years ago and we thought it to be a high number. Last month I talked about a shark named “Cuz”. He has a very easily identifiable dorsal fin and through this we recorded him making 2 successful predations in five days. We also identified him breaching on the decoy through one of Chris’s still photographs as well as observing seal entrails trailing from his gills on underwater video footage that we had shot. We then did not see him for about three weeks but he has now returned and has been at Seal Island now for the last week. Yesterday we saw him make another successful kill!
Another three sharks that are very easy to identify have also been recorded to be making a high number of kills in short periods of time.
More interesting behaviour that we have observed is that on three separate occasions we have recorded a larger shark to displace a smaller shark once it has made a successful predation. On two of the occasions the smaller shark half breached for no apparent reason other than possibly displaying some sort of body language. On the third occasion the larger shark that displaced the smaller shark and finished off what remained of the seal was a shark that we had not seen for two years. He is now just under 4 meters in length and is identified by a very badly injured dorsal fin. We first saw him in1999, but have not seen him for the past two years.
I have also been looking at dorsal fin identification photographs that we have taken in previous years and found images of “Cuz” from 2001. He also “starred” in the BBC shark documentary called Smart Sharks and we have photos of him circling Robo Shark!
Although we have seen so many more predatory events this season we have seen very few sharks at the boat in a baited situation. Also, there have been sharks that we have seen at predations, but not at the boat.
We have not seen any of our local sharks this season. By local I mean sharks that we see every year such as Rasta, Black-white-black, Notch Fin, Staywith etc. There seems to be a certain size range of between 3 meters and just under four meters sized sharks that we see and Rasta, BWB and Notchfin would all be larger than this now. Rasta is probably about 4.2 meters which would make her sexually mature as are the two males NotchFin and BWB. Although I miss them incredibly we hope that they have gone on safely to start the next step in their lives.
There is still hope that we may see them again as we have seen a large number of sharks this year that we had not seen for two years so maybe it is just a different cycle.
In the meantime we have got to know some great individual sharks that we will now be on the lookout for. We have also been seeing many small white sharks, at least 6-8 different sharks between 1.9 meters and 2.8 meters. So we are also very much looking forward getting to know this new generation!
Last month I spoke about how upsetting some predatory events can be with regards to watching an animal loose its life. This month I want to share a very heart warming story about a very clever “number 2” seal!