Diving with elasmobranchs: a call for restraint
George H. Burgess, Florida Museum of Natural History, USA
First published July 1998 by the IUCN/SSC Shark Specialist Group in Shark News 11
As curator of the International Shark Attack File, I have a special interest in shark/human
interactions and have followed closely the development of ecotourism dive operations involving
elasmobranchs. Most prevalent are attractions involving the feeding of sharks.
At least three types of shark feeding operations occur. Metal or PVC shark cages are used mainly in white shark Carcharodon carcharias
dives at numerous locations worldwide; also by blue shark Prionace glauca
and reef shark Carcharhinus
spp. feeding attractions in California and Australia, respectively. Chain mail suits (no cages) are utilized by other operations largely targeting blue sharks (e.g. in California) but also in at least one Bahamas carcharhinid dive.
Shark feeding operations provide the best opportunity for most divers to see sharks close at hand, in the wild. These are grey reef sharks in the Red Sea.
Photo © J. Stafford-Deitsch.
Finally, many feeding operations do not provide tourists with any protective gear (Bahamas, Florida, Maldives, and probably other localities). The common denominator in all operational types is chumming or baiting. Some go so far as to promote hand-feeding of sharks or even to 'train' their clients in hand-feeding techniques.
Non-feeding observation dives with whale sharks Rhincodon typus
, basking sharks Cetorhinus maximus
, and manta rays (Mobulidae) and stingray (Dasyatidae) feeding operations also take place.
My reservations about feeding-type dives are based on four interrelated
factors: the safety of the divers; the likelihood for negative publicity
directed at sharks if a shark bites a diver during one of these dives; the
possibility for ecological disruption; and potential negative impact on
multi-user recreational use of the feeding area.
Shark cage diving generally appears to be safe. I am unaware of any
serious injuries to divers, excepting biting wounds to hands placed
outside the cage. Chain mail and no-protective-gear dives have
resulted in injury to participants. Chain mail suits offer
protection only from small to medium-sized sharks.
However, the tooth tips of even small sharks can penetrate
the mesh resulting in injury - well documented in the
much-replayed video involving Valerie Taylor. The
powerful jaws of larger sharks may produce crushing
injuries even if teeth do not penetrate the mail. A large
shark with serrated, shearing teeth, e.g. a white, tiger
, bull Carcharhinus leucas
, or dusky
, would likely be able to cut
through such mesh. The metal mail may even be
electromagnetically attractive; white sharks, in particular,
are well documented biters of metal ship hulls and propellers.
In the Bahamas, where unprotected dive-with-sharks
operations developed quickly as a tourist draw, more
than a dozen injuries have occurred in the last several
years, at least two quite serious. Most were not publicized
because of efficient damage control by local operators.
Perhaps fortunately for the operators, most victims were
host dive masters, but a serious injury to a diving tourist
Last year I took part in an unprotected Bahama
feeding dive to view its design and safety. The experience
was exhilarating. An aggregation of about 50 sharks
(blacktip Carcharhinus limbatus
, Caribbean reef C. perezi
, and nurse
) were attracted to a frozen fish 'chum ball'
at a site utilised continuously (3-4 times a week) for several years.
Hundreds (thousands?) of bony fishes were similarly attracted. I did
not feel threatened by the sharks swimming above and around me as
we knelt on the sand bottom of a natural 'amphitheatre.' I did note one
blacktip, apparently low in a dominance order, confined to the
perimeter of the circling mass of fishes and reluctant to approach the
central chum ball. It exhibited apparent displacement or frustration
behaviour: periodic mouth gaping, increasing over time, and occasional
erratic swimming movements, including back hunching and pectoral
fin dropping. This type of behaviour has been observed immediately
prior to attacks on divers at other Bahamas shark feeding dive sites, and
is similar to gray reef shark behavior observed by Nelson et al
in the Pacific.
To reduce risk of shark attack:
- avoid diving in an area known to be frequented by sharks
- avoid diving in waters known to contain animal carcasses and blood
- avoid wearing shiny objects and contrasting colors while diving
do not touch sharks
An unanswered question is whether
individual bait-entrained sharks are more or less
dangerous to humans than their wild peers.
Observations of feeding reef sharks in the
Bahamas, which largely ignore divers, could
suggest 'no more' or even 'less' of a threat.
However, shark attack rate is profoundly
influenced by the concentrations of sharks and
humans occupying the water at the same time.
Increases in either generally result in an increased
probability of an attack. Obviously, high
concentrations of both sharks and humans are found together in a
small area in baited-shark dives. It is also clear that sharks attracted to
bait are in a heightened state of excitement, some approaching or
achieving frenzy. In addition, the unnaturally high concentrations of
sharks pursuing a limited resource (the bait) may lead to increases in
density-dependent agonistic behavioural displays (see box above) and
increased likelihood of attack. Furthermore, we do not know how the
food-conditioned sharks behave when the free food stops. Recently a
documented attack occurred on a diver swimming at a Bahamas
feeding site on a non-feeding day.
Many dive operations actually encourage ecotourists to touch the
sharks. At least one offers "shark feeding instruction." Such ill-considered
activity promotes irrational human behaviour like that
prominently displayed in a recently published US dive magazine
devoted to diving with sharks. The cover depicts a diver holding a
2-2.5 m Carcharhinus
, hands on snout and dorsal fin. A photograph
accompanying one story ("Friendly Encounters") captures a diver
grabbing a ride on the tail of a "16 ft" white shark. Another article
("Cool and Cuddly Sharks") is accompanied by photos of divers
hugging sharks. I am not a shark attack alarmist - at the ISAF we have
consistently tried to put attack in perspective and turn media attention
to more important conservation-based shark issues - but we cannot
ignore the fact that sharks are wonderfully designed predators that can
and occasionally do harm humans. While some entrained sharks can
be approached and even handled readily, do we want to send the
message that divers routinely can approach, touch, and even hug
sharks in other situations? I can't think of any
situation where grabbing
the tail of a 16 ft white shark is advisable.
The recent rise in the number of inshore baited white shark dives
has raised a serious concern: will these operations attract a larger
number of white sharks into the area, resulting in an increased
probability of attack (and potentially serious trauma and fatality) on other
user groups operating there? Whites are a more serious threat to
humans than most carcharhinids - they are larger and normally
consume larger prey. I believe a short-term localised increase in their
number is a real possibility; with that increase comes a greater chance
of whites and humans interacting.
Ecotourism dives aside, shark attacks on humans are rare. Nevertheless,
shark attack still is of great interest and concern to the public. The ISAF
routinely provides advice on how to reduce the already tiny chance
of attack. It is ironic that shark-feeding dives freely violate several of
the axioms of conventional wisdom advocated by virtually all attack
researchers (see box above). That more than two dozen reported attacks have
occurred worldwide during shark feeding comes as no surprise to
those who study shark attack.
If safety of participants was the only concern, I would not object to
shark feeding dives, assuming, of course, that divers are duly
forewarned that injuries have occurred and that the sport carries an
inherent risk (currently, many operations maintain bites have not
). Any injury or fatality then could be rationalised
as an unfortunate accident. However, when such a serious attack
does occur - and I predict unequivocally that it
will - media coverage will be tremendous. The
tabloid press predictably will hype a story
involving a diving tourist who loses a hand or
arm during one of these operations. Imagine
what reaction a fatality will bring! Actual video
of the incident is likely to be available to tabloid
television as these dives are routinely taped by
host dive operators and participants alike.
Needless to say, the shark will not be portrayed
favourably - the "Jaws" image will be reinforced
. The recently reshaped, biologically accurate public
image of sharks that many have worked so hard to foster will be
undercut quickly and decidedly.
This is of equal concern in the shallow-water shark-feeding areas, where the feeding operations are altering the natural system. Based on my personal dive experience and those of others, it is clear that the concentrations of sharks and bony fishes at feeding sites are unnatural. It is normally difficult to see blacktip or reef sharks in non-feeding situations in the Bahamas; they tend to avoid divers, are quite skittish, and (except for nurse sharks) are rarely encountered while diving (unless spearfishing).
The lure of the feeding operations, of course, is the guarantee of success in giving divers a chance to see and
Gray reef shark Carcharhinus amblyrhynchos during a shark feeding dive.
photograph sharks which are largely oblivious to the divers. However, the resident sharks and some bony fishes at these sites are now trained 'show animals' and at least partially dependent on free food.
That the Bahamas sharks are indeed entrained is demonstrated by
their response to the sound of boat motors. Dive operators routinely
rev their engines as they approach the feeding site in order to attract
the sharks, which rapidly arrive, surrounding the boat long before the
first food or diver hits the water (sound Pavlovian?). Similar entrainment
has been reported at Australian feeding sites.
Groupers (Serranidae) at some Caribbean and Bahama feeding
sites are similarly well-trained, rising from the reefs in search of
handouts from divers entering the water. At Grand Cayman, where
diver feeding of reef fishes was fashionable for years, I observed
mushrooming populations of sergeant-major Abudefduf saxatilis
yellowtail snapper Lutjanus chrysurus
. They became pests at
feeding sites, hovering around divers looking for handouts (and in
the case of sergeant-majors, frequently biting divers' fingers).
The highly migratory nature and differing reproductive strategies
spp. prevents direct analogy to these situations,
but it seems possible that their population size is increasing locally at
feeding sites. We do not know if such local concentration of sharks at
feeding sites allows natural levels of density and distribution to be
maintained over adjacent areas. Alternatively, the feeding sites may
simply relocate sharks from nearby areas and overall populations may
be stable or even in decline. No hard data are available, but the large
numbers congregating around feeding sites indicate that repetitive
feeding attracts sharks from wide distances. Feeding may promote
higher than normal local shark population levels since food is readily
obtainable at virtually no energetic cost. Additionally, localised
clustering of sharks and associated bony fishes entrained to feeding
may present an easy mark for poachers, as it did in the Bahamas when
rogue fishers wiped out a local aggregation of sharks associated with
a shark-feeding attraction.
Conversely, while some operations use otherwise discarded
remains of recreationally caught fishes as bait, others obtain chum or
bait fishes by spearfishing. Localised depletion of reef-fishes may
occur in these areas. Some South African white shark dive operators
reportedly catch juvenile bronze whaler Carcharhinus brachyurus
and smooth hammerhead Sphyrna zygaena
sharks to use as bait. As
with reef-fishes, repetitive fishing for these species in a small area may
lead to reductions in local populations.
Impacts on other water users
The presence of sharks entrained to the sound of a motor may lead to
localised loss of multi-party recreational activities such as fishing,
spearfishing, and traditional skin or SCUBA diving where divers are
not interested in encountering sharks en masse
. If sharks appear
whenever a motorboat visits a region, anglers are likely to lose their
hooked catches to opportunistic sharks or have the sharks frighten
away potential catches. Skin and SCUBA divers seeking sharkless
diving will encounter unwelcome escorts. As noted above, a tourist
diving at a feeding site on a non-feeding day was bitten on the head
by a carcharhinid shark. We have heard of a diver who had a shark
follow his outboard motor-driven boat from dive stop to dive stop,
eventually ending in a bite.
I am of the opinion that inshore feeding of sharks is not in the best
long-term interest of an area's economy. While the activity will draw
in ecotourists, inevitably a serious shark bite will occur, producing
significant trauma or death. The ensuing negative publicity likely will
result in the loss of that segment of tourists as well as at least some
others who do not wish to meet sharks regularly during their dives.
Pelagic shark-feeding cage operations may be of less consequence
than inshore unprotected dives. The feeding sites generally are
located far away from centres of human activity, entrainment of the
sharks is less likely, and the ecotourists are adequately protected.
Whale sharks, basking sharks and mantas
Whale shark and manta ray ecotourism dives have appeared recently,
primarily in the Indo-Pacific. Basking shark ecotourism has potential
in some temperate waters. Activities focusing on these large planktivores
raise some of the same concerns historically directed at ecotourism
operations targeting whales; that the natural behaviours of these
species will be altered by the proximity of divers and boats, and
possibly spotter airplane noise and shadows. Strict regulations address
observation and harassment of marine mammals, and stipulate specific
separation requirements in the USA. In contrast, 'riding' whale sharks
and mantas is shown in some magazine photographs and television
videos and evidently is viewed as a desirable activity by some. This
situation has been addressed in Western Australia (see article "Whale shark management programme, Western Australia"),
where human-whale shark interactions are now managed and
monitored. The development of similar protocols elsewhere would
This does not appear to be of such concern, although there is some
potential for injury where it occurs (several localities in the Caribbean
and Maldives, and perhaps elsewhere). Video footage of a shallow-water
feeding operation in the Virgin Islands shows numerous large
swimming amongst and through the legs of
tourists standing in waist deep water, knocking some off their feet. It
is likely that a large spine will be encountered sometime during a fall.
The 'media image' problem, however, is not likely to arise, nor are
there concerns over multi-user recreation. Ecological disruption is
Dive-with-sharks operations have been lauded as a positive
environmental experience for those divers who can afford this activity
and vicariously for thousands of television viewers of documentaries
and dive programs. Certainly allowing many people to see sharks in
is good publicity for these animals and helps to dispel the 'man-eater'
stereotype. But are entrained sharks performing on cue really
exhibiting any more natural behaviour than we see in trained circus
animals? Does swimming in circles and gnawing on a frozen 'chum
ball' or taking bait fishes off a spear or out of the hand or mouth of a
human constitute 'sharks in the wild'? Public aquaria offer basically
the same view of sharks without fostering the 'eating machine' image
enhanced by frenzied feeding.
It appears that the pendulum has completely swung as a newly
restructured shark image emerged in the shark-feeding dive community.
Sharks have been transformed from being blood-thirsty man-eaters to
playful puppies by some of those most closely tied to shark-feeding
operations. As often is the case, the truth lies somewhere in between
these two extremes. Based on the safety, ecological, social and
conservation considerations noted above, I believe that scientific/
conservation endorsement of most shark-feeding attractions is unwise.
On balance, it appears that sharks have more to lose than to gain by
I thank Matthew Callahan, Kevin Johns, Robert Robins and Franklin Snelson
for providing constructive comments on this contribution.
Nelson, D.R., Johnson, R.R., McKibben, J.N., and Pittenger, G.G.
Agonistic attacks on divers and submersibles by gray reef sharks,
: antipredatory or competitive? Bull.
Mar. Sci. 38(1): 68-88.
George H. Burgess,
Florida Museum of Natural History,
University of Florida,
Gainesville, FL 32611, USA
PDF of original article first published 1998 in SHARK NEWS