Cage diving with sharks raises several concerns, the main one being that feeding any wild animal can affect their behaviour and disturb the natural balance. For this reason, Florida introduced a ban on feeding wild sharks in November 2001.
Links have also been made between feeding sharks and an increase in shark attacks on humans. Campaigners are concerned that chumming conditions the sharks to swim closer to shore in search of this regular source of food. Cape Town's Shark Concern Group says: "It is not a good idea for humans to taunt an apex predator by throwing food and blood into the water. It is no surprise that human interaction is leading to more attacks."
A shark attack victim in South Africa - one of the main locations for cage diving with sharks - has called for a moratorium on cage shark diving activity and chumming, concerned it has lead to an increase in shark attacks. The community also feels it is an unnecessary activity of which the ecological implications are largely unknown. Some people argue that the practice shows no respect for these endangered species.
However, some diving operators say chumming only attracts sharks that are already in the area. "Chumming has got nothing to do with it," says Michael Rutzen, owner of Shark Diving Unlimited. "We chum with animals that occur naturally. Chum where there are no sharks and you don't get any." Rutzen adds that shark diving has a vital role to play in re-educating the public and protecting the great white. "We have to show people these animals to ensure their survival. It's no different from viewing leopards and lions."
This is a view shared with those who believe cage diving with sharks can help to improve the animal’s negative public profile. Ali Hood, director of Britain's Shark Trust, said that cage diving could serve to educate the public, be educational at the same time as allowing tourists to see a great white up close. The Shark Trust says it has yet to receive compelling evidence to connect shark tourism with an increase in shark attacks and recognises that, in the vast majority of cases, attacks do not take place near shark dive locations.
Diving with sharks is a large contributor to tourism in South Africa, where the animal is now designated a 'marine tourism species' - a status already enjoyed by whales and seals - meaning it may in no way be impaired or injured. This makes it possible to legally control tourism activities with these animals and disturbances must be reduced to a minimum.
While some shark diving trips are used for carrying out research on shark behaviour and sexing the animals, others are mainly for the entertainment of tourists, although they often claim to play an educational role. There are things operators can do to minimise detrimental effects, such as limiting the number of people diving in one location, preferably some distance from the coast and other areas frequented by people, and providing lessons in shark biology for diving representatives.