SEASON IS ON THE WAY
weather at the coast plus the medias thirst for hype plus the
publics craving for high drama can only mean one thing: shark
attacks will soon be in the news.
sharks attack people? How often do attacks actually occur? Must we really
contemplate a visit to the beach with terror? Such questions come to
mind as shark season approaches. Fortunately, the answer to these and
many other shark questions can be found in Sharks: The Animal
Answer Guide by Gene Helfman and George H. Burgess (Johns Hopkins
University Press, 2014). Sharks is available in paperback
and as an ebook.
answers more than a hundred questions about the taxonomic group of cartilaginous
fishes known as Chondrichthyes. The group includes not only the characteristic
torpedo-shaped, large finned, toothy creatures we think of as sharks
but also the familiar rays and skates. All have cartilaginous skeletons
rather than being bony like other fishes.
of the worlds species of animals and plants, even those that are
seemingly well studied, many biological questions remain only partially
answered or even completely unresolved. Why, for instance, does a shark
swim with its dorsal fin above the surface even in deep water? One explanation
is that because of their amazing sense of smell, sharks swim near the
top of the water to detect floating or maybe even airborne scents. If
so, the extended fin would be merely an artifact with no obvious function.
The authors do point out that fins circling a swimming person make life
easier for Hollywood filmmakers during dramatic, suspenseful moments.
that sharks have to swim continuously to keep breathing is only partially
true. Not all sharks swim all the time. Some take breaks to lie on the
bottom. These sharks breathe by sucking water into the mouth or through
spiracles, two openings on the top of the head. For sharks that must
stay on the move, water enters the mouth and exits through the five
to seven vertical gill slits on the side of the head. The obvious slits--along
with the bullet-shaped nose, big teeth, and distinct dorsal fin--make
it easy even for children to identify the stereotypical image of a shark.
the question concerning your odds of being attacked by a shark, the
answer is simple, straightforward, and not at all terrifying. In the
United States, your chances of being attacked by a shark are less than
1 in 11 million. You are more likely to win a $1 million Powerball payout
(assuming you buy a ticket) than you are to be attacked by a shark.
According to the book, the chance of being killed is less than
1 in 264 million. Clearly, the danger of being attacked or killed
by a shark while youre at the beach should be quite low on your
list of things to worry about.
As to why
sharks attack people, the book presents both facts and speculation.
Some bites are attributed to defensive or aggressive responses by sharks
in special situations. Some are believed to be actual feeding attempts.
But whether the human was mistaken for a common prey item, such as a
seal, or the shark was actually trying to feed on a human would be hard
to determine. Experts believe that most people along U.S. coasts are
bitten not by great white or other well-known predatory species but
by common blacktip sharks, which reach a length of less than 7 feet.
in the book I had never thought to ask: what is the best way to
take care of a pet shark? Apparently, that is a question some
people actually ponder and the authors provide the answer. So if you
have a pet shark or plan to acquire one, you will definitely want to
get this book. You might also do so if you are merely curious about
this remarkable group of animals that share the world with us.
you have an environmental question or comment, email