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Shark Bytes

August & September 2008 Shark Bytes

written by Monique Fallows

Posted on Tuesday, 30 September 2008

Dear Readers,

 

This update is a little late so my apologies. I am going to update you on our shark news for August and September so you may need to find a quiet moment to enjoy hearing about the sharks.

 

In July I mentioned that the predatory activity was great down on years gone by and we were wondering if it would be happening at all this year. True to form days after this comment the tell-tale signs of intense predatory predation stared to show.

 

On one particularly miserable Sunday morning we had to delay our departure time due to pelting rain. When we eventually arrived at Seal Island a large shark breaching out of the water in pursuit of a seal made it immediately evident that the sharks were in hunting mode.

 

I think we recorded a total of 18 events that morning and on top of this we seemed to be close enough to may events that we were able to see the entire event from the initial breaches to the seal eventually evading, or not.

 

On one particular event a large shark breaching as high as I have ever seen a shark breach. It completely missed the seal but the launch itself must have been a good 2 meters clear of the water, indeed an impressive sight.

 

We also observed a good number of prolonged chases. The rain was torrential and the wind moderate so each turn was made even more dramatic as the spray was intensified by the elements.

 

I was so enthralled by what we were seeing I spent the entire morning standing in the pouring rain, and quite frankly I hardly noticed!

 

Having been at Seal island for the last 9 seasons I can honestly say that it is possible for us to get a feel for the cycle of the behavior that takes place, or is about to take place. In the following days we could feel the build up and with a few good weather days predicted preceding a cold front we felt something big could potential take place.

 

Still we were not quite prepared for a record breaking day that lay ahead.

 

Immediately on arrival a number of events were in progress and this did not stop the entire morning. At one time we witnessed 5 separate events going on within seconds of each other and more than once we had 3 events simultaneously.

 

By the end of the morning we recorded 45 separate natural predatory events between a Great white shark and a cape fur seal.

 

Without actually being here and seeing this it is difficult to describe what it is like to be part of a natural history event such as this. I know I went into complete sensory overload and not only where Chris & I exhausted by the end of it, but our crew and guests as well. It was very difficult to take it all in and to try and remember what exactly we saw.

 

This is now the highest number of events we have ever recorded in a morning at Seal Island. To try and comprehend how special this is I think I should point out that the next busiest Great white shark predatory spot is considered to be The Farrollon Islands off San Francisco. Scientists here record in the region of 40 events per season. That’s per season, not per day, week or month!

 

Of course the sharks here are feeding on much larger Northern Elephant seals, and the intense hunting behavior that we witnessed on this morning was something unique.

 

So, naturally some would ask what made this morning so special. We believe that a number of crucial factors all came together. There was a very high concentration of great white sharks at Seal Island at the time and as there was an approaching cold front a large number of young cape fur seals were returning back to Seal Island, giving the sharks plenty of opportunity.

 

The sea conditions were perfect flat with a lot of sunlight so this made spotting the events from our point of view a lot easier and although we did miss some events I think we were close to being accurate, if only under recording by a few.

 

I also think that with a high number of sharks present in a relatively small area the competition for food must be extremely high and this may force the sharks to hunt at any given opportunity, whether their chances of success are fair or not.

 

You might also wonder about 5 events taking place at one time. Again, just our opinion on this is that the sharks rely heavily on sound and vibration to pick up on the seals.

 

A small group of seals may be attacked by one shark and consequently be split up. The noise from this initial attack will attract other sharks to this area that will then in turn most likely pick up on the other seals. Often these simultaneous events happen close to each other and I think this further strengthens the above argument.

 

Well, science and my opinions aside...this was an incredible natural history event that I was very privileged to witness and all present on the boat that day admired and respected both shark and seal in a brutal battle for survival.

At one time we witnessed 5 separate events going on within seconds of each other and more than once we had 3 events simultaneously.

We continued to see high predatory events of the next few days but after this actually dropped off again. In season’s gone by we would normally see 4 weeks to 6 weeks of intense hunting. This season was only about 10 days. We were still seeing predations but not in those absurdly high numbers.

 

Up until about the 20 August we did have a lot for great days with shark interactions around the boat. When booking guests after 10 August I usually caution that the sharks can be slow around the boat for cage diving. But this August we had many great days and got to “meet” a number of fantastic individual sharks that we had not seen before. Two sharks in particular were two very relaxed females. We named each “Malla” and “Hook Mouth”. Some people think it is silly to name sharks but from our point of view it helps greatly in getting to know the animal and for keeping data. It is also really nice for our guests to be able to identify with these sharks and to get to know some of their history.

 

In August we also graced with the presence of a very feisty smaller shark we called “Round Fin”. He is quite a handful and whoever was on the bait had to be extra vigilant with this shark. A shark lunging for a bait always goes down well with the guests but it is not so fun if it is your responsibility to keep the bait away.

 

I also want to point out here that at some point around 20 August we noticed a very slight change in behavior that in our Seal island language translated to the end of the season being neigh.

 

Literally from one day to the next the sharks went from their normal feeding pattern of consuming a seal almost immediately to suddenly taking a little bit longer in the actual consumption of the seal carcass. When there are a lot of sharks present I think that the sharks need to finish off a meal as quickly as possible in case it is lost to another, possibly larger shark.  So, maybe if there is not the threat of a possible meal loss it might not be so imperative to finish off so fast. The change was so dramatic that to us it was a big indicating factor that the season was ending.

 

Towards the end of August Cape Town was hit by a series of powerful cold fronts. We were not able to go to sea for almost a week. During this time Chris & I kept ourselves busy by our version of storm chasing. This is not quiet running after tornados but the wild winds and rough seas are fascinating to us. In our area winds reached up to 70 knots (140 km per hour) and the sea swell pushed to a massive 7 meters (23 feet). A lot of coastal homes were damaged to some degree and then surprising on the day after the storm passed a large swell that came directly into False Bay did a lot of damage to a number of restaurants at Kalk Bay. There was not a lot of wind and this was just raw power of the swells.

 

Once we were able to get back out at sea the shark activity was very slow and there was one trip were we did not see sharks. But as things settled down we did start to get some sightings. Although we have had some good trips in September it is definitely at the end of the season and I think by the end of the month the sharks would have left Seal Island to follow their summer habits.

 

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