June 2005 Shark Bytes
Posted on Thursday, 30 June 2005
First up I have great news to share with everyone. Disney Hong Kong has officially decided to not serve Shark Fin Soup on its menu. This has come as a result of tremendous pressure from people all over the world. I know that many of you wrote and sent letters to Disney voicing your dissatisfaction so well done and thank you! I think this goes to show that even as an individual you can make a difference.
The great white sharks at Seal Island have been fantastic this past month although very different to the 2004 season. Right from the start of the month we have had high numbers of different sharks around our boat whilst trying to attract them. I think the slowest day we had was 8 different sharks whilst the busiest was an unbelievable 21 animals. In the last 6 years that I have been at Seal Island this is the most we have recorded and identified around the boat. On this particular day the weather was just perfect with not a ripple on the water so viewing was at its most optimum. We have also had a lot of days we had seen in the region of 15 different animals, and what is more interesting is that from day to day we were not seeing the same sharks. On most days we would identify sharks that we had not seen the previous days. This goes in standing with our belief that most of the sharks that hunt the seals at Seal Island only stay for short periods of a couple days at most, purely using Seal Island as a feeding station.
One of the great things about having many sharks around the boat at one time is observing the behavior between the different sharks when they encounter each other. Quite a few times we were able to clearly observe 4 different sharks at the same time. Although they mostly tolerate each other they do not like to get too close the each other and this is when their body language to each other comes into play. We can usually tell when another shark in close by just by the way the shark we are watching behaves.
The sharks we normally see at Seal Island are in the size region of about 3,5 meters in length (10 feet) but this month we have seen a great variety of sizes. Most people want to see large sharks but it is also just as special to see small sharks. They are usually very clean animals and also sometimes have “small shark syndrome” where they act as if they are bigger sharks! So we have seen quite a few sharks between 2 and 3 meters as well as a number of sharks that are longer than 4 meters with the largest at 4.3 meters (13 foot). Our experience in the past has been that these larger sharks do not stick around the boat long but in June they had been interacting with us most of the time.
One of the most exciting and rewarding aspects of working at Seal Island is waiting and hoping to see sharks that we know return to the Island. In June most of the sharks we know from last year and previous years were sighted.
Scratchy, a young female that we saw for most of last season was sighted. I think she was the most recorded shark from 2004 but we have only seen her twice this month. This may be because she is a smaller shark and she might not be allowed to come to the boat because more dominant sharks are around. Last season we really struggled to get sharks to come to our boat although we knew they were there from the intense predatory activity we were observing. We are not doing anything different but interestingly we have recorded a huge decrease in the number of predatory events. This probably has to do with the low amount of seal movement during the day. It makes sense that if the prey is not moving around you aren’t going to see a lot of hunting behavior. From previous night trips to Seal Island we have found that the seals leave to feed offshore in their thousands and in a constant stream. Perhaps the sharks are having a go at them at night? Nowhere in the world have they been recorded to actively hunt at night but they have to be eating something and we are seeing seals on the Island with fresh white shark bites.
This can all change though and we have to see what July brings.
Other sharks we have seen include a large female we call February. We first saw her in 2002 and she has now grown to a very healthy 4.2 meter animal. She is a fantastic shark that is very curious around the boat. We also noted Wonky Tail who has returned to the Island for the last 5 years as well as Linford who is very distinguishable due to an abnormal clasper which is the size of a butternut squash. He has always had this abnormality and seems to be in good shape. We first observed him while feeding on a whale carcass in 2002. We have also seen Schumi although being a smaller shark she seems cautious about staying around the boat with so many other sharks present.
A week ago we also saw a very familiar fin pop up that belonged to Cuz. We really got to know this shark last season and he was well known to put his head out of the water as well as gape continuously along the side of the boat. The first time we saw him he did not do any of this, again because there were so many sharks around the boat. The second time we saw him, which was last week, was towards to end of the day and it was fairly quite around the boat. Well, he gave a quite a show constantly poking his head out of the water, completely out of his own accord. We are not sure why some sharks do this but have a feeling that they are merely looking to see what the boat is. The good news is that he looks fantastic.
Some sad news is that we have seen a few sharks that are not looking so good. One average size shark has had a serious run in with what we presume to be boat propellers and seems to have injured its eye badly. We can easily see that this has affected its judgment. This is not good news for the shark in terms of trying to catch prey as well as threats from its own kind. For the past two seasons as well as this season, there has been white shark tagging study undertaken by a research group. We do not know too much about it but we think it has to do with monitoring the sharks movements using telemetric tags and listening stations. Very useful information will be gathered but unfortunately we have seen a number of sharks sporting old tags with tremendous growth on them. The tags are no longer transmitting and although the actual transmitter part of the tag should have fallen off, they have not. Goose barnacles have attached themselves to these tags and in some cases the growth is the size of two fists. These growth masses are then constantly rubbing against the skin of the shark causing raw, open bleeding wounds.
I think I better follow with a happier story … and I have a pretty good one. One of the mornings we were looking out for predations when we spotted a large seal returning to the Island. On closer inspection we noticed that the seal was covered in trawl netting. I have often spoken about these seals before and refer to them as green seals. In the past we have seen these seals attacked by white sharks. Of course they are very easy for the sharks to pick up on as the net creates tremendous drag and noise in the water. These seals are also very easy for the sharks to catch. Each time we have seen sharks attempt to catch them, they have caught them and then immediately let them go uneaten, often times with the seal badly injured. We presume it is because the seal is covered in the netting and the sharks recognize this as foreign.