Shark fin soup
Shark fins are highly prized for use in shark fin soup, a high status dish that can sell for over £100 a bowl, especially in Asian countries where growing wealth has increased demand. As demand is met, sharks become over-fished, fins are harder to come by and the soup is therefore even more of a status symbol.
Scientists estimate that up to 273 million sharks are caught and killed each year, many of them purely for use in shark fin soup. Hong Kong alone imported the fins of more than 28 million sharks in 1999. Often sharks are caught, their fins cut off and they are then thrown back into the sea, still alive, where they either bleed to death or drown: this process is know as Shark Finning. Using DNA, it is now possible to identify shark species from their fins, a development which may be significant in monitoring the impact of this trade.
Demand for shark meat is booming and it is now possible to buy it in most major supermarkets. The shortfin mako which is said to provide the ‘best’ shark meat is in high demand, but even more vulnerable species, such as the porbeagle shark, are also taken. Fisherman will often claim that they only take species that are of low risk to extinction and therefore they are fishing sustainably. However, given the slow growth and small number of offspring of many of these target species, it is only a matter of time before they are classified as vulnerable or worse. Fishermen will then simply move on to the next species and decimate another population.
The trend for increasing demand for sharks may be indicative of the fact that so many other fish species are declining and that people have been encouraged to eat fish as a healthy alternative to meat. The Food Standards Agency, however, has advised against giving children shark meat to eat because of high levels of methyl-mercury that can damage the nervous system.
skin and oil
Shark skins can be tanned and used as an alternative to leather (for belts, boots, bags, etc). In theory and on a small scale, this could be a useful by-product of a sustainable and managed fishery.
Sharks have traditionally been fished for oil. Squalene is extracted from shark livers and used as a lubricant and in cosmetic and pharmaceutical products. It can take up to 3,000 shark livers to produce one tonne of squalene.
Sharks are cartilaginous - they have cartilage instead of bone. The cartilage is used in traditional medicines and is sold in powder or capsule form as a cancer treatment. There is no scientific evidence to suggest that it is in any way effective against the disease and the 'medicine' can be very expensive. There may, however, be other benefits in maintaining shark biodiversity to produce artificial medications, for example, shark cartilage has also been used in the development of a synthetic skin for burn victims.
Sharks as entertainment
Typically only a few
benthic species of shark, such as
leopard sharks and
catsharks had survived in aquarium conditions for a year or
more. This gave rise to the belief that sharks, as well as being
difficult to capture and transport, were difficult to care for. More
knowledge has led to more species (including the large
pelagic sharks) living far longer in captivity. At the same
time, safer transportation techniques have enabled long distance
movement. One shark that never had been successfully held in
captivity for long was the great white. However, in September 2004
Monterey Bay Aquarium successfully kept a young
female for 198 days before releasing her.
The Monterey Bay Aquarium has since held a number of White
sharks with different levels of success.
Take a look at the
Monterey Bay Aquarium website
for more information. In addition, the largest fish in the
ocean, the whale shark, has now been kept at a number of aquariums
around the world but not without protest. As the whale shark
is a large highly migratory species, we do not believe it to be an
appropriate species to house within an aquarium, irrelevant of size.
No aquarium will ever be a suitable home for such a species.
Instead we believe that ecotourism is much more appropriate, as long as it is
well controlled, like that of the Ningaloo whale shark tours in
In addition, the largest fish in the ocean, the whale shark, has now been kept at a number of aquariums around the world but not without protest. As the whale shark is a large highly migratory species, we do not believe it to be an appropriate species to house within an aquarium, irrelevant of size. No aquarium will ever be a suitable home for such a species. Instead we believe that ecotourism is much more appropriate, as long as it is well controlled, like that of the Ningaloo whale shark tours in Western Australia.
The health of the ocean is important for all marine species. Pollution from human activity often ends up in the sea. Sharks are at the top of the food chain so they are likely to have a higher concentration of these toxins that build up in the body fat of their prey. Because human development and subsequent pollution often occurs in coastal areas, important shark nursery areas are also at risk.
A study in Southwest Florida's Caloosahatchee River showed that newborn bull sharks carry traces of drugs that humans excrete after taking medicine, or introduce by flushing unwanted pills down the drains which then make their way to local river systems. According to the first-ever study of pharmaceuticals in wild sharks, led by Mote Marine Laboratory and supported by the Charlotte Harbor National Estuary Program and the National Oceanic and Atmospheric Administration. Scientists found that the new born bull sharks had detectable levels of drugs, which at present were not thought to be of serious concern but could be fatal in the long term if left unchecked. The bull sharks encounter treated wastewater near its source as they are one of only a few sharks able to live in freshwater rivers.