Posted on Saturday, 31 May 2014
Dear Shark Lovers,
As I sit here writing about our May shark experiences yet another big winter storm is rolling in signalling that our late summer I was so enjoying has definitely come to an end!
This past May has been one of our best for great white shark sightings in the past 5 years at least and I look forward to telling you all about it.
Big Sharks Visit Seal Island
In years gone by, and up to 2008/2009, we would normally record our largest size sharks at Seal Island in the months of April and May. But, if you have been following Shark Bytes over the years you would have noticed that our shark sightings have seemed to have taken a bit of a downturn come Mid April to early June and we certainly did not see the very big sharks over this period either. Chris & I would often comment to each other how the seasons had changed, but this May things seem to have shifted right back again.
Already at the end of April I had reported that we had seen some very large sharks, in the 4 meter plus size range, and even an extremely impressive 5 meter female. This has continued through the whole of May, and in fact sightings of very big sharks kept increasing throughout the month.
On almost all trips we would see a shark of 4 meters or bigger and on some amazing trips we would see 2 to 4 individual sharks in this size range. Many have been in the 4.2m – 4.3 meters range and we have also had one of 4.5 meters plus. These are very big sharks and will weigh up to 1.5 tons, making the girth of these animals particularly impressive.
Also of interest is that some of these large sharks have been recorded on multiple trips and they have been interactive with the bait and around the boat, you can imagine what an exciting and impressive cage dive it is with such a large slow moving animal.
Interesting Observations of these Large Sharks
Worth mentioning is that fact that of the large sharks we have been seeing, they are both female and males. Males reach maturity at about 3.8 meters and females at around 4.2 to 4.3 meters so it has been very exciting for us to see a number of mature animals. These female sharks would thus be 15 years or older, a long time for a shark to stay alive in our oceans today.
A female shark that was seen on five occasions had a healed bite mark from another Great White shark across its left gills. This could possibly be a mating scar.
Another very interesting shark we have gotten to know well this past month is a 4.2 meter female. We have named her “Iris” and it has been a great pleasure getting to know her! She is a slow moving, gentle shark and she appears to be very comfortable interacting with us at the boat. Our many guests this month that have had the privilege of cage diving with her have had absolutely amazing encounters, as well as all of those that have seen her from the surface too. Now, the very interesting thing about Iris is the 6 or 7 tightly packed rake marks just in front of the top of her head. These are healed injuries and after having many good looks at them we are theorising they are Orca tooth rake marks. Scratches from seal teeth and claws are generally fairly fine, not too deep and not widely spaced. Bite marks from other great white sharks are usually crescent shaped and not neatly raked. Outboard motor injuries are generally clean slices and fairly wide and cage and boat injuries are usually scuff marks that are most typical on the dorsal fin or caudal fin. These rake marks are consistent with what you see on humpback whale flukes, dolphin’s and orca’s themselves. There are only 2 recorded interactions between great white sharks and orcas, and in both cases the orca was king. It appears that Iris had a lucky escape and although we cannot be 100% sure these injuries are from an orca, we are not sure what else they could be inflicted by.
Sharks with Copepods
Copepods are parasites that are sometimes seen on great white sharks (as well as other species of sharks). They are brown in colour and the actual “animals” imbed in the shark’s skin and appear furry in nature as the eggs trail off it in long streams. The copepods are often packed closely together with the result of big brown furry patches on the sharks.
We only occasionally see great white sharks with copepods but when we do it is often a batch of sharks that are seen together. This leads us to assume that all these sharks would have been in an area close to one another where they picked up the copepods and then again travelled to Seal Island at a similar time period.
Many of the sharks we saw this season, including the large sharks, were covered in varying amounts of copepods.
One of our favourite sharks this May was “Harry”. Harry is covered in copepods with his caudal keel, top of head and dorsal fin carpeted in the stuff! It’s very noticeable and as we felt we could not call a shark “Hairy” (!) the name Harry was born! He is about 3.7 meters in length and a pretty feisty shark around the boat. He likes fast rushes on the bait and can be a real handful to the crew. On one occasion he did a full breach on the bait and one of our guests managed to catch it on her iPhone.
Other Shark Personalities this May
We have had a number of “long stay” sharks this month and a couple of returnees. Duex Rossi often puts in an appearance doing her usual staying low with an odd go at the bait. “Kinky” is a fairly large 3.7 meter male that returned again after a 3 week absence. He is a great shark to observe around the boat as he is fond of doing tight turns in very small spaces.
“Zamalek”, a 3.6 meter male has also been recorded on and off. This is the ultimate shark to cage dive with as he does tight circles around the cage and a bait is hardly needed to keep him around the boat.
We have also had a number of sightings of “Mr Frisky” who was seen in July and August last year. He has distinctive light white pigment marks on his dorsal fin and can be fairly assertive on the bait (hence his name!). He does not appear to have grown too much but we have been really excited to see him again.
It is interesting how many people follow the different sharks on our facebook page and we often have new guests on the boat getting really excited when a well-known, and well publicised shark on facebook arrives at the boat. We even have some guests asking before the trip is a certain shark is around and are we likely to see it. Interesting how social media has created a certain kind of bond to the sharks we know well. On this note the famous “Colossus” may have made an appearance on a predation about two weeks ago. Neither Chris nor I were at sea that day but one of our crew is pretty sure it was him and we are waiting to see the pictures taken by a guest.
Breaches & Predations
Despite the high number of sharks we are sighting on a daily basis (on some trips up to 12 different animals) there is very little hunting going on at Seal Island. We are not sure what the sharks are doing at the Island if they are not hunting but we think a reason they are not hunting is due to the limited amount of young of the year seals going out to feed. The bulk of them will still be drinking their mother’s milk and thus there is no reason to leave the safety of the Island, and therefore little chance for the sharks to hunt since this is the size seal they are preying on most of the time.
We have seen the odd event here and there but nothing on an intense level.
Breaches on the decoy have also been a bit thin on the ground but we have started having some success in the last week or so. As always we tend to focus more on natural predation than on the decoy tows as it is always better to see the sharks do what they do naturally.
We are starting to approach the build-up of the predation season and we look forward to what will be happening the deeper we get into June, if the number of sharks at the island is anything to go by it could be quite spectacular.
No Dolphins, No Orca's
It’s funny how quickly things can change…. February, March and up to the middle of April saw record numbers of common dolphins with schools of up to 3000 strong. We were sure that with this amount of dolphin around it was just a matter of time until the orcas arrived in False Bay. But alas, the huge bio mass of sardines that were present in False Bay moved out of the area taking with it the schools of dolphins and with that any good chance of finding the orcas this year. We have kept very thorough records of all the sightings we have had in False Bay and especially of the details around the 23 hunts we observed on the dolphins over the last few years. What we have learnt from this, amongst other things, is that dolphin behaviour is very different when the orcas are around or have recently been in the area. Dolphins tend to be a lot less sociable around boats, calves are kept tightly in the middle of schools and most noticeable is the fact that the dolphins will often burst into a panicked rush out of an area despite no visible threat being seen. Clearly they are stressed. There was a two week period in late March where this behaviour was very evident. Since then there have been no signs in False Bay of the dolphins being nervous and as such we have concentrated our focus on other areas where sightings have been showing orca activity to be most frequent.
Chris and I have heard of many orca sightings just outside of False bay, around Hout Bay and several from the canyons off Cape Point. There have been reports from Still Baai and at least two reports from Table Bay, both of a large male orca swimming close to pods of dolphins. Despite being very close to where the orcas were seen on several occasions we have just missed them.
That said I can’t tell you how disappointed I am not to have seen them this season …. I have been waiting a whole year to have the chance again! Anyway, I guess that is how things go with wildlife and the opportunity can still present itself at any time as long as we are out there with an eye open and ear to the ground!
A big thank you to our network of friends and colleagues who have kept us abreast of all sightings.
Something to ponder over is whether or not orcas have had an effect on our poor great white sharks sightings over the April and May months the last few years. Chris disagrees with me, but I think we will have to keep this theory in the back of our minds.
As we move into June we have been hit by a number of cold fronts leaving us in no doubt that winter is here. The famous big wave at Dungeons has even had a number of sessions for big wave surfers and looking ahead in the next few days the large 7-8m swell that is forecast might make things exciting out there!
We have 3 weeks of Sardine Run expeditions this month and I hope to be writing about some amazing experiences in the next Shark Bytes edition.
Until next month!