Posted on Wednesday, 30 April 2003
Dear Shark Lovers
The windless days that are supposed to characterise the month of April finally came true towards the end of the month and we were able to get out into the deep on quite a few occasions.
As we get the closer to our winter, the warm Agulhas current is moving further off shore and our run from Cape Point has been about 30 nautical miles. This takes a good 2 hours and I sometimes wonder what our guests on board think when we seemingly stop in the middle of nowhere and start waiting for sharks. But, there are many things that we take into account and of course the most important being food source.
There has been a lot of small yellow-fin tuna being caught as well as some long-fin tuna. In fact on the way home one evening we suddenly saw the water in front of us just explode in a frenzy of fish feeding on the surface. As we got nearer another area to the left would erupt and then to the right. It was an incredible sight to see and the entire area of fish feeding just got larger and larger until an area the size of a football field was being churned as the small yellow-fin and skipjack tuna chased millions of anchovy into a ball.
Unfortunately the visibility was very poor and we were unable to get into the water, but we could imagine the sights beneath.
Sometimes we see the best things on our way out or back in. On a previous trip to this one we came across a pod of about 100 pilot whales and a few very large bottlenose dolphins that were moving together. We would go a little ahead of them, turn the motors off and then drift onto them. Everything is very quiet and all you can hear is the sound of the whales spouting and gently moving through the water. As they got closer to the boat they would sound just beneath the surface and we could look down on their black and mottled white bodies….just beautiful!
Although there is very little difference between long-finned and short-finned pilot whales (both occur off the Cape Province) we suspect that they were short-finned. They supposedly associate with bottlenose dolphins and are also often found in the same area as tuna. It is assumed that they are both preying on squid or small fish.
We had another surprise encounter with a very large male sperm whale the following day. This is the first sperm whale we have seen so it was fantastic to get a real-life look at Mobi Dick! Sperm whales can be found worldwide but usually around continental shelves (where we were). Unfortunately these whales are considered vulnerable due to selective hunting of large males, but researchers believe that because of continued protection from large-scale commercial whaling, they do have a good chance of recovering.
Despite all these distractions we did managed to see some sharks and had one particularly outstanding trip. After waiting about an hour and a quarter a big blue shark came racing into the bait. At 2.5 meters she was the largest blue shark we had personally encountered and 2 pilot fish accompanied her.
On closer inspection we found her to be very well “worn” with many bite marks around her pectoral fin area. The very end tip of her nose was also missing and gave her a very distinctive “pink nose”, whom she was dubbed.
Two things could have caused these injuries. At 2.5 meters she is on the verge of being sexually mature, so they could be mating scars or she could have been attacked by another shark while she was hooked by a fisherman. The injured nose would probably suggest a run in with a fisherman. The good news is that these days more and more sport-fishermen are releasing sharks. Commercial fishing is what is doing the damage.
“Pink Nose” turned out to be an extremely dominant shark and successfully chased off two Mako’s that had made very brief appearances earlier. This was very exciting to watch. The Mako’s would wait in a 20-meter radius around the bait and Pink Nose would make wide circles displaying aggressive body language towards them. These consisted of dropped pectoral fins, gaping mouth movements and turning sideways towards them.
What we are continually seeing here is contrary to what is seen between Mako’s and blues off California. In California it has been documented that Mako’s are the more dominant species.
They soon got the message and we did not see them again. After a while a second large blue shark joined her. This male was also around 2,5 meters and although he was made to play second fiddle, he was not completely chased away. It was fantastic to watch them underwater as they eyed each other out. As we were enjoying watching this another Mako arrived on the scene. At 1,2 meters, he was smaller than the other two Mako’s. We immediately thought that his presence would not last long.
But, we were wrong. This shark was so confident and cocky as he would dart around the bait and rush the blue sharks. We were treated to seeing amazing bursts of speed that this shark is famous for and he even managed to gently bite Pink Nose. He was literally tolerated by the blue sharks and although there were occasional outbursts from the blues, the mako was allowed to stay in their space.
So for the next 3 hours in the water we could watch two large blue sharks, with pilot fish, approach the bait gently and then had this mad Mako whizzing around them. A large seal made a very brief appearance, but was investigated and chased off by the Mako straight away, leading us to believe that the Mako had “small-dog syndrome”!
These trips into the deep are very special to us. Each time we go out there we see something special, no matter how small. We have also learnt vast amounts about Mako and Blue sharks. No one previous to us has tried to actively look for these sharks so very little is known about their status in our area. We have encountered mostly small sharks of both species and only a very few blue sharks that may be in the size range of being sexually mature.
So where are these large sharks? And how many are there?
What we have learnt is that, just like white sharks, each shark has its own personality and all have slightly different behaviour.
We probably only have a few trips left with these sharks until the warm water gets too far for us to go, but the white sharks should be starting to return to Seal Island. The young of the year seal pups will soon have to fend for themselves and their inexperience leaves them very vulnerable to being preyed upon by white sharks.
I hope that at the end of May I will be able to tell you all that we have seen the return of some of our most famous and most loved sharks of Seal Island!