Protection

The role of great white sharks in the ecosystem

Great white sharks are apex predators; they sit at the very top of the food chains of many marine ecosystems. Their function is to keep the balance and health of the ecosystem by maintaining a check on the populations of other species through a complex web of trophic relationships. Sick or unfit individuals of a prey species are more easily eaten by great white sharks and in this way great whites help those fish or marine mammal populations stay healthier. But more importantly, theoretical and field studies have shown that if apex predators like the great white shark disappear from an ecosystem, the populations of other smaller predators lower in the food chain (usually preys of the white shark themselves) go out of control and the balance of the entire ecosystem is lost. When apex predators disappear, they can no longer prey on the smaller predators and keep them under control and as a result, the numbers of smaller predators swell. This uncontrolled growth of one or more smaller predators can affect a large number of other species though increased predation and competition and this is how the entire ecosystem can fall out of balance and loose its health. This is why in order to keep the balance of marine ecosystems it is extremely important to maintain healthy numbers of apex predators like the great white shark!

Declines on GWS abundance in several parts of the world.

Since the release of the movie Jaws in the mid 70s, a craze for hunting great white sharks spread around the world and many of these magnificent predators died in fishing tournaments and other 'sport' fishing activities. Also, the end of WWII saw an uncontrolled global expansion of fishing fleets pursuing all kinds of fish to fill the consumer demand of an ever increasing human population. This meant that many sharks, great whites among them, were purposely and accidentally fished for decades. These two events together with the overfishing of many fish species such as blue fin tuna (a prey species of great white sharks), has caused an alarming decline in the numbers of great white sharks in various parts of the world. In the Adriatic Sea great white sharks have almost completely disappeared and they are now a rare species in the Mediterranean Sea. Other strong declines in white shark abundance have been reported in the east coast of the USA, and in parts of South Africa and Australia. For these reasons, the great white shark is considered a vulnerable species in the Red List of the World Conservation Union (IUCN) and it is likely that future assessments will list the white shark as endangered in at least some parts of its range.

Protection for Great White Sharks

Because of the concern over the future of great white sharks, Steven Spielberg's leading actor has been legally protected in several countries: South Africa pioneered its protection in 1991, a move that was followed shortly by Namibia,  and later Australia, the USA, and Malta. Mexico has included the great white shark in its list of endangered species and it will be legally protected in New Zealand starting in April 2007.

During the 13th meeting of the Convention on International Trade in Endangered Species of Flora and Fauna (CITES) that took place in Bangkok in October 2004, a proposal to improve management and monitoring of trade (mainly jaws, teeth and fins) from the world’s largest predatory fish was finally adopted. The proposal which was spearheaded by Dr. Ramón Bonfil and submitted jointly by the governments of Madagascar and Australia, called for a listing of the great white shark on Appendix II, which would provide key data on trade and therefore allow better management of the species. Fortunately, the proposal was approved in what was a record of majority votes for a shark species in the history of CITES and since 2005 the species has been listed in the Appendix II of this convention.

"I'm thankful that the international community recognizes this species for what it really is—a perfectly adapted oceanic predator and a key player in many of the world’s marine ecosystems," said Dr. Ramon Bonfil to the media at the end of the meeting. "In spite of its reputed ferocity, this species is ironically a victim of what is undoubtedly the planet’s most deadly species—humans. This listing will help us manage the trade that currently threatens the great white shark by requiring data showing that harvests are not a detriment to the species."

However, the listing under CITES only serves to monitor (not stop) international trade in great whites. This is obviously not enough to guarantee the survival of the great white shark because domestic fishing and consumption are still allowed in most nations. For this reason, there is still an urgent need for more countries to adopt legal protection for great white sharks and to enforce those laws so that less great white sharks perish in the future.

How does ST contribute to GWS conservation?

The studies that you are supporting by adopting one or more sharks are difficult to fund but extremely important for the adequate protection of great white sharks. In order to protect white sharks efficiently, managers and scientists need to learn more about their basic biology and ecology. Things such as the preferred habitats of great whites, their migratory routes and timing, the areas where they give birth and mate, are crucial information for designing efficient protection and recovery measures. So far scientist knows surprisingly little about the life cycles of great whites. As a useful example, until only a few years ago, nobody knew that great white sharks can traverse entire oceans during their migrations and go from one continent to another, only to come back to the exact same point where they began their journey (a discovery which incidentally, was made by Dr. Bonfil and his colleagues from South Africa!). We still don't know where and when white sharks mate or give birth. Only through sophisticated technology and increased support for scientific studies such as those funded through Shark-Tracker is that scientists will one day be able to map the most important pieces of the white shark life-history puzzle, and this will lead to effective management and conservation regulations. Your contribution is already making a great impact!

An additional benefit of your support is that the scientific studies carried out by Dr. Bonfil make it possible to engage the government agencies in charge of fisheries and conservation in countries with important great white populations into joint conservation research efforts. This has proven to be an excellent way to plant or encourage in these agencies the idea of the need for further legal protection for great white sharks while at the same time influencing the public opinion in these countries. Last March 2003, Dr. Bonfil and his team hosted New Zealand’s Minister of the Environment during their white shark tagging expedition, and almost a year later, New Zealand will enact legislation to fully protect these fabulous and enigmatic sharks! This is another way in which your support is helping further the cause of great white sharks.