Keep feeding the sharks

Keep feeding the sharks

tiger shark

A large female tiger shark (Galeocerdo cuvier) circles a group of divers (credit: Jim Abernethy )

Divers will travel the world to get to good locations to dive with sharks. It can be big money too. Some dive operators will feed an area to attract sharks for their clients but it’s a controversial practice.

In some regions such as Florida the baiting for sharks have been banned while in other regions it’s accepted by local authorities. It is a controversial practise though among marine conservationists. Will feeding sharks with ‘chum’ – ground up fish that is used as food – change the behaviour of sharks and interfere with their natural feeding and foraging behaviour? [pullquote]Not only did we discover that ecotourism provisioning did not affect tiger shark behavior, we found that tiger sharks undergo previously unknown long-distance migrations up to 3,500 km into the open Atlantic.[/pullquote]

Does feeding sharks at dive sites change foraging behaviour?

In a study, now just published in the British Ecological Society, a team of 5 marine biologists decided to take a closer look and try to get evidence one way or another. what they found was that feeding the sharks did not impact on the behaviour of sharks subject to the practise.

The team from University of Miami Rosenstiel School of Marine & Atmospheric Science tiger shark populations at two locations, Florida – where chumming is banned – and the Bahamas – where feeding the sharks is permitted. satellite tracking was used to check the shark movements.

Free-roaming of tiger sharks not affected by baiting.

The research team proposed that if feeding the sharks did impact on tiger shark behaviour then the sharks at the Bahamas should congregate and concentrate around the feeding areas. They would be expected to have less free-roaming behaviour than the sharks at Florida who without having food provided would have no reason to stay close to the dive sites.

The researchers did not just discover that the Bahamas sharks were free-ranging but that they also travelled over distances that were 5 times larger than the tiger sharks of Florida. 

Not only did we discover that ecotourism provisioning did not affect tiger shark behavior, we found that tiger sharks undergo previously unknown long-distance migrations up to 3,500 km into the open Atlantic. These apparent feeding forays follow the Gulf Stream, an area of high biological productivity that concentrates shark prey,” said Dr Jerald S. Ault one of the paper’s authors.

 “Given the economic and conservation benefits we believe managers should not prevent shark diving tourism out of hand until sufficient data were to demonstrate otherwise,”  explained Dr Neil Hammerschlag, another of the paper’s authors.

Dive tourism is major contributor to local communities.

Dive tourism is an essential part of the economy for many nations, offering a long-term and sustainable industry. While shark populations are constantly under attack by shark finning operators  some countries are responding to the threat by banning shark fishing in their coastal waters.

Living sharks more valuable than dead ones.

The Maldives is one country that has banned shark fishing. There the money earned from shark dive tourism is far greater than the money bought in by killing sharks. The ban was bought in in 2010 when shark dive tourism was discovered to contribute about 30% of the nations Gross National Product (GDP). A study considered that the value of a living single grey reef shark was worth $3,300 each year it was alive.

Last year a study undertaken by Hammerschlag and graduate student Austin Gallagher was published that demonstrated that shark diving tourism was now generating more money globally for local communities than killing sharks.

External sites:

Functional Ecology: Don’t bite the hand that feeds: assessing ecological impacts of provisioning ecotourism on an apex marine predator.

University of Miami: Global Shark Currency: the distribution, frequency and economic value of shark ecotourism.