From: awright@gssec.bt.co.uk (Alan Wright)
Newsgroups: rec.scuba
Subject: Re: Shark Attacks (long)
Date: 17 Dec 92 14:53:50 GMT
Organization: BT, Software Engineering Centre, Glasgow, UK

In article <1992Dec14.092341.25987@resonex.com>,
dan@resonex.com (Dan Kell) writes:

First off I should say that I am not a shark expert and am probably
setting myself up to be shot down. I read about them and watch any film
I get hold of. So this stuff is taken from the current literature. Also,
I am assuming we are talking about sharks like the Great White, Tiger,
Bull, Blue etc. There are many of the 350 species of shark which are
totally harmless, or are only remotely dangerous because they have sharp
teeth but are extremely unlikely to bite.

Some of this applies more to people on the surface than to divers
underwater. Generally, if you are a diver in a situation where there
is the possibility of an attack you should spend as little time on
the surface as possible.

|> 1. With the exception of extraordinary events, like the sinking of the 
|> Indianapolis in WWII, do shark attacks most commonly occur by a single
|> shark or a group of sharks?

Sharks may travel alone or in groups. So far I have only seen speculation
on why they travel in groups - social behaviour or protection of the
young. They have been seen in groups of several hundred. People have
reported seeing well over 1000 Hammerhead sharks in a group.

In costal waters and in rivers I think most attacks are by single
sharks. In open water it will depend on the type of incident and
how much noise and scent is present in the water surrounding the
incident.

The sharks may appear anywhere from 20 minutes to 24 hours following
a boat incident. Even if you are on a lifeboat they may still appear.
Fish in the open ocean are attracted to shadows on the surface because
they stands out. Throwing refuse over the side adds to the problem.

|> 2. Is it more dangerous to be in the water with a single shark or multiple
|> sharks?

Multiple sharks are definitely more dangerous because of the danger of
a feeding frenzy. If one starts to feed they may all go wild. However,
even if there is only one shark you may still be in significant danger.
Obviously, if you are bleeding then you are in trouble, but it is also
dangerous if you are not fully clothed - probably to do with smell.
Sharks are also attracted to light colours such as yellow or orange.

The other thing to remember is that sharks do not only bite to feed.
They also bite to investigate things and in this case do not remove
any flesh. However, given the power in their jaws this may not help
the victim if he/she does not get medical attention quickly. Once you
are bleeding even if the shark that bit you goes away others might
arrive.

|> 3. Are you more or less likely to be attacked if you exhibit aggressiveness
|> toward a shark who acts aggressive towards you?

From the case histories I have seen it doesn't matter. Do what ever
you can but avoid injuring the shark but stabbing it. If you don't
kill it you may trigger a self-preservation instinct and the shark
will kill you. Secondly, the injured shark may attract other sharks
in the area.

One report I read was about someone who was bitten across the chest
(I think by a Great White). As the shark released him he managed to
roll across its back, stick has hands in its gill slits and hold on
tight. The shark went wild and they both ended up on a reef, out of
the water. To teach the shark a lesson he punched it on the nose and
it bit off his hand.

|> 4. Short of getting out of the water, what is the best thing to do if a
|> shark becomes aggressive? Best defensive posture, place of refuge, etc.
|> I know getting out of the water is the best, but what if you can't right
|> away?

There is very little you can do in the water. Don't thrash about. If the
shark comes straight at you, some have suggested that shouting as loud as
you can and slapping the water as hard as you can as the shark gets close
may deter the attack.

One final point. Sharks have very good sensory powers and a single shark
can be very selective when attacking. If there is one injured person in
a large group then very often only this person is attacked. Also,
generally, people who have gone to the aid of victims are not attacked.
The exception to this is a feeding frenzy when everything in vicinity of
the sharks is in danger.

|> Dan K.

-- Alan
--------------------------------------------
awright@gssec.bt.co.uk (Alan Wright)
BT, Software Engineering Centre, Glasgow, UK
--------------------------------------------
Newsgroups: rec.scuba