Newsletter - 01/06/2001

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The Loggerhead
The Official newsletter for The African Diving Experience
www.africandiving.com
Volume 7 Date: 01/06/2001

                   We hope you enjoy the May issue of our monthly newsletter.

Index:

<1) What's happening on the African Diving Experience
<2) Shark of the month  - Bull Shark (a.k.a. Zambezi)
<3) Tiger Shark Feeding on Aliwal Shoal, good or bad?
<4) Book Review - Reef Fishes and corals: Eastern coast of southern Africa  by Dennis king
<5) Tired of the same old dive sites? Dive the unexplored waters of Island Rock. Best of all its local!!!!
<6) Equipment tips -how to maintain your cylinder
<7) Website of the month

1. What's happening on the African Diving Experience

We would just like to remind you that the winter is coming and this is the time of the year when equipment
specials starts to pop up. So if you need some more gear, this is the time of the year you should be looking.
Do keep in mind that even if it is cold in the Gauteng and inland areas, diving is still absolutelly amazing at the Natal Coastline.

We added the following dive sites to our growing list of locations:

     Protea Banks  -  With the help of Roland Mauz from African Dive Adventures
     Wondergat  -  With the help of Micheal Holtzhausen from the Technical Diving Academy
     inLichtenburg.

Special thanks to both these people for helping us in supplying all of our visitors with dive site information.
Talking about dive sites, have a look at article 3 of this newsletter about diving in Island Rock. That trully
sounds amazing.

We are still trying to gather information on diving locations in in the Cape province. If anyone can help us get
in touch with such information, please contact us as soon as possible.

Interrested in a banner exchange? Do contact us at the following e-mail
willem@dpa-training.co.za

2. Shark of the month - Bull Shark (a.k.a. Zambezi)
Class: Chondrichthyes (Cartilaginous fish)
Sub class: Elasmobranchii (Sharks and rays)
Order: Carcharhiniformes (Ground sharks)
Family: Carcharhinidae (Requiem sharks)
Genus: Carcharhinus leucas (Bull shark)

                             Bull Shark ( Carcharhinus leucas)
                            Known in SA as the Zambezi Shark.

The bull shark is known as the Zambezi as it has been found several hundred kilometers up the great Zambezi River and seen in Zambia.

The Zambezi is a large shark (the total length up to 3,2 meters) with a short, broad and blunt snout, small
eyes and triangular, saw-edged upper teeth. This is a Grey shark with a white underside, with no conspicuous markings on the fins. The Southern limit off the East Coast of Africa is Cape St. Francis. The Zambezi is our summer shark and leaves after the sardine run June / July and avoids our August cold water and is seen again early October.

The Zambezi is able to maintain its electrolytic balance whether in the ocean or in fresh water for extended
periods. 40 years ago it was common to see the Zambezi make its way over the sandbank barring the
entrance of the Umkomaas River, so as to hunt grunter and bream up stream. The river is now so silted up
from soil erosion this incredible sight is no longer possible. However Mtunzini, St Lucia estuary and the Kosi
bay estuary are prime areas for the Zambezi to drop her pups, as they provide prime shelter for the Zambezi
pups, with plenty of suitable prey. The St Lucia Estuary when the river is in flood, the Zambezi can still be
seen worming their way over sandbanks to get into the estuary after grunter and bream. The Zambezi is even seen chasing shoaling fish onto the beach and themselves beached, at the estuary mouth, and waits for the next wave return them back to the sea. The female Zambezi is also seen in the St. Lucia estuary or at the estuary mouth, jumping out of the water and spinning in the air to facilitate dropping her pumps.

The Zambezi is well adapted to feeding without the use of its eyes; hence it has small eyes and not handicapped in finding prey in the zero visibility of the Zambezi River, or turbid coastal waters. The
explanation of a shark attack being caused by the similarity of image, was the US Navy’s explanation for a
shark attack, whereby a surfboard was considered similar to a turtle and someone in a wet suit imaging a seal  or a dolphin. Current research indicates that a top hunter practices. Hence someone bitten in turbid water on  a surfboard or swimming and let go is an unfortunate incident. This is not an attack but an incident, yet the media miss represents the happening, as the drama sells print. Humans are not part of the shark’s food chain  and if in clear water and clearly seen by the shark, such a mishap as described is unlikely. For divers there has yet to be an unprovoked attack on a diver by a shark!

The main culprit of the shark attacks / incidents, off the KwaZulu Natal coast, was attributed to be that of the
great white. Re evaluation of the photographed bites indicate that the main culprit is the Zambezi. The
International Shark attack file is also being re-evaluated and many recorded white shark attacks / incidents,
have now been identified as that of the bull shark. The bite profile and upper triangular teeth of large bull
sharks are easily mistaken for the bite of a white.

The Zambezi is a powerful omnivorous predator and feeds on a wide variety of bony fish, sharks, rays,
mantis shrimp, craps, sea snails, squid, mammalian carrion, sea turtles and occasionally garbage.

Environmental accounting is a method of assessing the live value of a natural resource. The tourism money
that the Zambezi's draw to the towns adjacent to the Protea Banks is R50000 per Zambezi seen. A dead
Zambezi is only a fraction of this value and should be protected against indiscriminate killing by fishermen and spear-fishermen. We also have a major problem with unmonitored foreign trawlers in our EEZ long-lining and finning. The present Sea fisheries / Marine Coastal Management act states that these vessels should have satellite tracking and South African observers aboard. Marine Coastal Management banned finning 5 years ago, but so far none of this legislation has been applied or enforced. President Bill Clinton’s last act whilst in power was to ban finning in the American EEZ.

By:  Andrew C. R. Cobb, (Andy) Tel/Fax 27 (0)31 9164239
P. O. Box 386, Winklespruit, 4145, South Africa
Email:
andycobb@iafrica.comhttp://www.adventurescuba.co.za
SATSA Member #: 766

Picture

Photo from http://www.fishbase.org

3. Tiger Shark Feeding on Aliwal Shoal, good or bad?

We started a poll on whether feeding Tiger sharks should be fed on Aliwal Shoal or not, just prior to our
May newsletter. Since then 50/50 has covered the topic and showed footage on how this feeding takes
place. If you haven't voted yet be sure to visit the following url to get your vote in. Vote on
http://www.delportdupreez.co.za/diving/form.htm

So far the results are as follows

Number of votes recieved = 37
Stop the feeding = 32 (86,5%)
Keep on feeding them = 4 (10,8%)
The other person was not willing to choose a side.

Let us know what you think about this issue.

 
4. Book Review - Reef Fishes and corals: Eastern coast of southern Africa by    Dennis king

Dennis King is one of South Africa’s best underwater photographers and in this guide you can see why. This
is wonderful book for those divers who wish to know more about the fishes they see around them when they
dive. It has 294 full color  photographs of the most common fishes and corals with a description of each.  For
the relevant fishes it also show the male and female form as well as the juvenile. Every diver I know has this
book and it is one of the best guides available.

Published by Struik
Retail price: R70 – R100

5. Tired of the same old dive sites? Dive the unexplored waters of Island Rock.
                               Best of all its local!!!!

We recieved this e-mail from Darryl and Debbie who used to run a dive operation at Ponta.They have
recently started a dive operation at Island Rock near Sodwana Bay. We will let the e-mail speak for itself so
have a read through it and be sure to give them a call.....


"We have been at Rocktail Bay/Island Rock for 1 month now and things are looking good.  We have found 8
stunning dive sites so far, the majority 18m and shallower with the exception of 1 - Island rock Pinnacle,
which is 45m.  Huge game fish greeted us when we neared the bottom and the fish are definitely not used to
divers of any nature.  The potato bass are very skittish when they see us but the other fish are very curious,
coming right in to take a 2nd and 3rd look.  The coral reefs are absolutely stunning and totally untouched. 
Huge canyons appear from nowhere and we have found 3 swim-thru's on 1 dive site - much to my delight!
We saw our first paper fish last week (a green one) and were chuffed.

Every reef appears to have a resident honeycomb moral eel, mostly giants.  But the most impressive thing to
date is that there aren't 14 other divers dropping onto my buoyline to make my dive numbers 28!!!  Funny
side also is that there aren't any other boats to give you a conditions report so the 1st dive is a "guinea-pig"
event. The builders have just completed the dive centre and our accommodation so now we are going to be
full swing into finding more sites.  The last month has been so hectic, as we clean and dive we arrive back to
find the place in a mess again. Darryl claims that my broom needs unleaded fuel now because the petrol
stations can't keep up with the fuel supply!!

On Sunday we had the pleasure of bidding farewell to the mess and now it's work as usual. On another
interesting note, we have found a pod of dolphins who appear to live in the area and for wild dolphins they
have reacted unbelievably to the boat.  They actually charge in and swim alongside the bow of the boat and
when we stop they actually hang around to see what we are up to.  Amazing!! We have seen reef sharks on
almost every dive that we've done - just small ones but a shark all the same.  We have also spoken with
Andy Cobb and the guys from Sodwana who claim that the Raggies definitely congregate at Island Rock in
the summer months and have been seen by snorkellers.  Wouldn't that be great to have our own raggies
without the numbers of divers to intrude and interfere.  We have agreed to go into research on the
Raggedtooth sharks and will be doing such dives with our clients.

Darryl hasn't had much time to fish these days but we've been coming up and telling him how many seapike
and carcob we've been seeing.  The next couple of weeks will see that familiar figure once again on the
beach, fishing rod in hand, smile on the dial. We've had enormous response from the international divers and we had a couple from Sweden last week who had just come from Barbados and they informed us that the diving is better than Great Barrier Reef.  Nice to know hey. Check out the Divestyle magazine which is on
sale from 18 June 2001.  They came down to do an article on us and the lodge so you'll be able to get more
info from this.

I'm also hoping to get e-mail soon but you are so welcome to phone us anytime on our cell - 0828202142 as
we  have an aerial so the phone is on all the time.  Nice for me, at least my bill will be more realistic now.
Drop us a line, tell us how you are and what you've been up to.  Am planning to come to Jhb in September
for the Getaway show so would love to meet up with you guys sometime. Take care, it was great chatting to
you and enjoy 2001 diving, wherever it may take you. Best Regards   Darryl & Debs"

Date recieved 24 May 2001

6. Equipment tips - how to maintain your cylinder

· Keep water out - It is necessary to keep the cylinder, especially steel ones, dry as to prevent rusting from
the inside out. The best way to do this is to keep a bit of air, usually 30-50 bar, in the cylinder to prevent
moisture from entering. Also dry the valve before attaching your hoses and let a small bit of air out. This will
blow out any water left over from filling.  Have your cylinder inspected routinely - A cylinder needs to have a visual every year whereas a hydro needs to be done every four years. This will help in picking up any signs of rust or cracks, which can appear with time.

Source:
http://www.scubadiving.com

7. Website of the month
The following site are our choice for websites of the month:

http://www.ultimate-animals.com

Have a look at the awsome photos of Great White Sharks breaching the surface while hunting pray. The
photos was published in the National Geographic magazine and footage was shown on SABC tv, sunday
27/5/2001, on how they took these magnificent photographs.

Updated on: 06/03/2003