March 2013 Shark Bytes
Posted on Sunday, 31 March 2013
Dear Shark Lovers,
March has been a busy month with the return of the Great White Sharks to Seal Island, a very brave Short-tailed Devil Ray, a tragic event of stranded False Killer Whales on Noordhoek beach and a big storm at Kalk Bay Harbour.
Great White Sharks at Seal Island
After a long summer waiting for the Great Whites to return to Seal Island February and March have actually produced some really good shark sightings at the Island.
We started with some exploratory trips in early February and soon after that we were successfully running our first trips of the 2013 season.
These are early season trips so sightings would vary from 1 to 5 sharks per trip. As is often with nature some trips were quiet followed by a busy trip the following day, but on all trips all guests got good views of a great white shark.
There have been a few regularly seen sharks. Throughout February and March a 3.6 meter male has been visiting the boat. He is pretty feisty around the boat and as such the crew have nicknamed him “Al Capone”! He is a very exciting shark to see!
We have also had about 6 or 7 visits from a large 4 meter plus female. She is a beautiful shark with big white rosette blazes on both the left and right of her Dorsal Fin.
She is usually pretty slow moving and relaxed around the boat and will stay for extended periods. So, on these trips our guests have had great shark cage diving with the opportunity of seeing a really big female shark underwater, an impressive and fairly rare sight!
The start of the season always follows a general pattern in terms of the feeding behaviour of the Great white sharks.
They are not yet actively hunting the young cape fur seals. These seals are still too young to be leaving Seal Island to go and feed for themselves. They are still suckling their mother’s milk.
But, a different feeding opportunity is presented to the sharks and we think this is one of the reasons that we find a small number of Great white sharks at Seal Island at this time of the season.
There seems to be more sick and weak young seals this time of the year that drift off Seal Island. They do so off the Northern side of the Island as the prevailing Southerly winds wash them in this direction. Although these sick or already dead seals do not have a high fat content and thus do not give the sharks as much energy as a young healthy 6 month old seal, the sharks are using very little energy to predate on them. So, spending a small amount of energy for even a small reward is definitely worth their while.
We have observed and recorded a large amount of these scavenge events over both February and March, sometimes up to 8 in a morning and together with the data we have collected on this behaviour for the past decade or so since we first identified it we have been seen a very regular pattern of feeding behaviour. This is clearly based on seasonal opportunity developing in a very small quadrant of the island.
It is actually fascinating how localised the sharks are around Seal Island right now. We are only finding the sharks at the Northern side where as the Southern side, just 400 meters away, seems to be completely devoid of the presence of sharks. Just goes to show how focused the sharks are on what they are looking for and what they are wanting.
With regards to active predatory events (a shark chasing a live, healthy seal) there have been 2 events in March.
One took place nearly 2 miles from the Island. White Pointer was actually viewing a school of about 200 common dolphin at the time when 2 of our guests saw a shark do a full breach in pursuit of a seal … the seal got away after no follow up from the shark.
Also, one of our crew saw a full breach in the shallow area of the Seal Island channel whilst chasing a seal. Again, the seal got away, but slowly, slowly it seems the activity is starting to pick up.