Monday, September 20, 2010

Shark Diving: To bait or not to bait - that is NOT the question.

The question is HOW to bait sharks without causing them harm.

The Aliwal Shoal shark dive operators (South Africa) use steel cables and heavy chains to attach a perforated stainless steel bait drum.

I always found it quite upsetting to see the tiger sharks taking the cables, sharp nut screws, and the rusty chains into their mouths, and shake them violently.

Not surprisingly, given the strength of these massive sharks, their teeth get knocked out. Sometimes you can even see their jaws slightly bleeding.

All the teeth of the lower jaw are gone
Photograph: Wolfgang Leander (2008)
Click to enlarge

I suggested to adopt the method used at Tiger Beach: Thick nylon ropes, and plastic crates for the fish parts.

It's always a delicate matter to tell people, no matter how open-minded they pretend to be, or are, that things can be done differently, better.... "That won't work here; the tigers would cut the ropes and smash the plastic containers in no time." That was the comment of "my" former shark operator in a nutshell.

I argued that the Bahamian tigers never bite the nylon ropes and rarely, if ever, take the crates away or crack them.

Biting the chain - not the fish part attached to it
Photograph: Wolfgang Leander (2008)
Click to enlarge

Unfortunately, I could not convince the operator - he keeps using metal, as all other Aliwal Shoal shark dive operators, not caring about the problem, and the tigers keep losing their teeth and hurting their mouths.

This year I could see in various opportunities tigers sharks getting completely entangled in the cables after chewing on them. In order to not lose their grip on the lines the tigers started to roll which got them all twisted up in the steel cables and chains.

Unable to move or breathe, the tigers were getting dangerously close to asphyxiating hadn't some divers freed the hapless creatures from their ordeal. The sight was absolutely gruesome.

As a photo journalist I have fully documented the entanglements. The images are so disturbing and graphic that I decided not to post them in this blog.

Again, I brought this to the attention of my ex-shark operator. However, he was not interested in remedying these totally unacceptable incidents, and simply ignored my countless pleas to change the cables and chains for nylon ropes.

To build up an international image of a shark expert for oneself, and regularly contribute to "Shark Week", is one thing nobody, or few, would seriously challenge but to not show what I consider basic respect for the creatures one pretends to care for, sadly made me realize me that this operator is not at all what he wants others to believe he was: a committed shark lover.

Oh, well, insider views into the micro cosmos of the shark world have taught me that one should not expect much from its protagonists. The greed for money and ego satisfaction is often so much stronger than eloquently worded mission statements...

Back to the issue:

Comparing the behavior of the Tiger Beach tigers with that of their South African cousins, and after giving this some thought, I came up with an amateurish explanation that seemed to be logical: I figured that it must be the metal, perhaps a magnetic field around it, that attracts the sharks and incites them to munch on it.

Effectively, this is the reason why the Aliwal Shoal tigers bite the metal parts, especially the long steel cables, and thus run the risk of getting all twisted up in them.

While shark dive operators are generally proficient shark dive operators, they don't know everything about sharks. And since my knowledge about sharks is limited, too, I decided to ask my friend Dr. Samuel Gruber ("Doc"), one of the world's leading shark scientists, to enlighten me.

Here is what the "Doc" wrote back:


No brainer! Metal in sea water produces corrosion or galvanic currents which stimulate the tiger shark's ampullary system. They need not deal with induction of the electric field to magnetic field since they can directly respond to electric fields on the order of a ten-billionth of a volt per cm.

This is why we see white sharks on TV bite metal cages and dive platforms, and why bull sharks keep biting our props!"

It was Walter Bernardis of African Watersports who shared my concern and reacted promptly and constructively.

Walter runs a very successful tiger shark operation in Umkomaas, and is open-minded when it comes to improving procedures to ensure client satisfaction and the well-being of the sharks which are, after all, the dive operators' most valuable asset.

His suggestion how to keep the tigers from biting the cables and chains is brilliantly simple:

Hi Wolf -

I've come up with the perfect solution.

I've been thinking flexible hose all along but the answer is heavy duty water pipe - polycop - that won't just bend.

So if you've got a 9 m cable length you just slide 3 m length on, so that it can still fold up and fit on the boat but the tigers won't be able to get twisted up in it...

Will let you know when the next brain wave hits. :-)


OK, Walter, the next steps are rather simple, or so they seem. Test the tubing of the cables and chains as suggested, and get ALL the Aliwal Shoal shark dive operators to follow suit so as to effectively, and collectively, protect your sharks from being hurt unnecessarily while baiting them.

Go, Walter, go!!!!


sharkwise said...

Good to see the unscrupulous motives of certain greedy tiger shark operators are slowly being exposed. They can no longer hide in the blue wilderness!

lyn nelson said...

Really great detective work, Wolfer - protecting your great friends.

lyn nelson said...

Really great detective work, Wolfer - protecting your great friends.

iDiver said...

Every dog has it's day, or in this case, Wolf. Nicely written and from a personal standpoint it's about time people were told about what's going on.

Shark Diver said...

Home run reportage Wolf. Hopefully Mark and Co will see some light.

The Sharkman said...

Thanks for the eye opener Wolfie.
Keep up the great work.

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