174 Sharks: The Animal Answer Guide
backlit surfer or swimmer is not that different from that of a seal (see the dis-
cussion of ambushers in “How do sharks catch their prey?” in chapter 7).
White Sharks also attack divers who have speared a fish. Whether the
shark was investigating the sounds of a struggling fish or smelled fish blood
is unknown, but the human hunter then becomes prey. Abalone and sea ur-
chin divers frequently encounter White Sharks and attacks do occur, per-
haps because the divers are easy pickings as they hunch over their prey
rather than looking over their shoulders for bigger predators. Few peo-
ple collect abalone and sea urchins in waters where large White Sharks
abound, but there are exceptions, and some have paid a price. One picker
has been bitten three times by White Sharks in California waters but has
kept on diving.
Surprisingly, the most dangerous shark in U.S. waters, in terms of
number of people bitten, may not be the White, Bull, or Tiger (or Ham-
merhead, Lemon, Reef, Sand Tiger, mako, Blue, or White Tip). It is the
Blacktip Shark, a moderate-sized (2-m, or 6- to 7-ft) fish eater that occurs
commonly in the surf zone. Blacktip and Spinner (Carcharhinus brevipinna)
sharks are probably responsible for three-quarters of U.S. attacks, about 30
a year. We say “probably” because the average victim is not able to identify
those two species, and the tooth fragments that experts use for identifica-
tion are seldom recovered. Victims are usually young males in their teens
or early 20s who are surfing or boogie-boarding in the surf zone.
Another surprising perpetrator of many attacks is the Nurse Shark. The
most common “victims” of Nurse Shark attacks are again young males in
their teens or early 20s (do we see a pattern here?) who are snorkeling or
scuba diving in shallow water. Nurse Sharks don’t generally attack unless
provoked, something that happens more than it should because some peo-
ple can’t resist the temptation of pulling the tail of a Nurse Shark lying on
the bottom. Nurse sharks are among the few sharks flexible enough to put
their tail in their mouth, so an attack is clearly the animal’s defensive re-
sponse to having its tail pulled. Divers have also been bitten petting Nurse
Sharks, and a Florida diver in 2006 kissed one and received “lacerations to
upper lip.” Although Nurse Sharks have relatively small teeth, they can still
do damage because they tend to bite and not release their grip. As a result,
divers find a nurse shark attached to their hand or arm or chest or leg, one
that requires forceful, drastic means to remove. Such provoked attacks are
almost never fatal (except for the shark), although the round, craterlike
wounds are prone to nasty infections and often require skin grafts.
In the category of bizarre, unprovoked attacks we return once again to
the Cookiecutter. Before 2009, Cookiecutters did not appear in any of the
various international “incident” or “attack” files. But in March of that year
a swimmer attempting to cross the channel between the Big Island of Ha-
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