New research released today by the Secretariat of the Pacific Community (SPC) in New Caledonia demonstrates the frightening impact on shark populations that shark fin soup is having. The results of a study of 15 years of landing catches published in Conservation Biology shows that the worst affected shark species the white-tip shark has declined by an average of 17% a year over that time.
The research was carried out by a team headed by Dr. Shelley Clarke and it looked at the catch rates of blue, mako, and oceanic whitetip sharks from the Pacific Ocean. The team also looked at the size of the oceanic whitetip and silky sharks that were landed.
The survey showed that the size of the sharks landed were getting smaller as the more mature individuals were lost due to heavy overfishing. While the whitetip shark saw the biggest drop in population levels due to it being the favoured species by chefs the other species also saw ongoing declines in populations levels.
“Our research reveals alarming declines of 17% per year in populations of the oceanic whitetip shark, a species highly valued for its fins,” explained Dr. Clarke. “Also of serious concern are declines of 5% per year for North Pacific blue sharks, considering that this species is known as one of the most productive and abundant pelagic sharks. Overall, the data we analyzed show consistent trends for each species and area, even though they were collected from different fisheries.“
The size of the drop in whitetip sharks is particularly concerning as it is the only species of shark that is subject to international catch limits. The banning of shark finning – where the fins are cut off at sea and the rest of the shark is discarded – also seems to have had little effect on preventing shark number declines.
This was put down to the ineffective enforcement at the home ports of the fisheries vessels and also a complicated fin to body weight ratio that is used to restrict the finning of sharks. There is also a growing market for shark meat which means a higher level of fins can be bought in under the ratio even in those countries that enforces the finning ban.
“These findings underscore conservationists’ messages that most finning bans are not properly enforced, and alone are not sufficient to reverse shark population declines,” said Sonja Fordham, President of Shark Advocates International. “Prohibitions on at-sea removal of shark fins not only bolster finning ban enforcement, but also facilitate collection of species-specific fisheries data that are key to refining population assessments and informing the establishment of urgently needed shark catch limits.“
The findings could raise fears that the Pacific population of the whitetip shark could soon reach the threatened status of the Atlantic population. In the Atlantic the whitetip sharks saw a decline of over 70% between the years of 1992 and 2000. In the Gulf of Mexico its population of whitetip sharks decreased by 99.3% between the 1950′s and 1990′s.
The shark has gone from being one of the most prolific and common place sharks to one that can be rarely seen in its former habitat. In the Atlantic region the whitetip shark is now classed as regionally critically endangered. At current rates of loss the Pacific population could soon be joining it.
