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"Where and when to catch the great white shark.".

I recently came across a scientific paper which is a classic example of how to set about improving your catches of any species. Unfortunately the species in question was the great white shark and the bait would be a bit on the big side (a sea lion or elephant seal) for my spinning rod. Nevertheless it shows just what could be done in the right circumstances.

Great whites are opportunist predators living in cool seas. They feed on a range of prey species and like other predators, they tend to 'make hay while the sun shines'. In other words they gather to feed where prey are abundant. Off the coasts of South Africa and of California there are places where, at certain times, vast colonies of seals or sea lions gather to breed. Due to the fact that these mammals tend to swim near the surface of the sea shark attacks on them are often visible and may be spectacular - as was clearly shown in the recent 'Life on Earth' television footage.

By spending many hours at sea watching shark attacks it has been possible for scientists to build up a picture of the factors favouring shark strikes. It would be possible by using this information to virtually guarantee catching big sharks. Of course these rare animals are, quite rightly, protected and you wouldn't be allowed to fish for them but I thought that the results were so striking that they could be a good example to us all.

I'll just give a summary of the South African situation for starters and I'll try to explain why each factor was important. The sharks were eating Cape fur seals and attacks occurred mostly over the period from June to August. At this time of the year (their winter) the warm water fishes that sharks feed on at other times of the year, have moved away and the young inexperienced seals (easy meat) have just been weaned and are beginning to forage for themselves. White sharks have an amazing sense of smell and would have no problem locating seal rookeries (which must be pretty stinky).

Sharks attack from below. The seals can probably outmanoeuvre them if they know where they are and by sticking their heads under the water they can see them coming. Consequently, the sharks 'hide' by staying fairly deep down and viewing the seals against the surface light. The sharks also need a reasonable depth of water to let them get up speed for a strike and so they are not really a problem in the very shallow margins.

More attacks took place in northerly winds which carry scents out to the mouth of the bay thus attracting sharks, these winds also make the seals have to swim harder against the current and the disturbance caused reveal their presence to the sharks and make it more difficult for the seals to keep an eye open for lurking sharks. However, the sharks were less successful at completing their meal closer to the shore. Experiments towing dummy seals behind boats resulted in more shark strikes when the decoys were bulkier and caused more disturbance (make that popper splash hard). Sharks attacked in water ranging from 5 to 31 metres in depth but most were in the narrow range of 26-30 metres. Sharks were most successful in poor light when presumably they could see the seals without the seals seeing them. In bright conditions the success of shark attacks dropped dramatically and the sharks more or less stopped trying to catch seals.

Curiously it was noticed that just before a storm there were more shark attacks, it was thought that this may be due to seals anticipating the bad weather and heading for the beaches (running the shark gauntlet) but this needs further investigation. Infra-red observations have revealed that more seals may leave the coast under cover of darkness when it is safer but attacks may be enhanced by bright moonlight and by phosphorescence both of which would reveal the prey to the predators.

So, there you have it! From June to August, in 26-30metres of water at dawn or dusk or on a dull day, with the wind from the north, when a storm is forecast using a bait or lure that flaps and splashes like a struggling seal you would more than likely get a strike from a fish that would frighten the life out of you.

Given the same sort of scientific information (if it were available) it should be possible to target any other species from bullheads to bass or conger to cod. We all know that time and place are ninety percent of the battle when it comes to catching fish.

If you have any comments or questions about fish, methods, tactics or 'what have you.'get in touch with me by sending an E-MAIL to - docladle@hotmail.com

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