A large-scale study of the world coral reefs shows that the reef shark population is catastrophically declining. During the three-year period, almost none of the sharks were recorded with 19 percent of the reefs inspected, meaning that these predators are “functionally extinct” in the waters of six countries.
The reason is probably overfishing, which is due to the sharp increase in population and poor governance in the coastline. However, the good news is that, as the results obtained by a team of researchers indicate, conservation measures can restore and manage reef shark populations.
Over the past few decades, we have known mostly about shark populations from incomplete data – from existing records of their catch during industrial fishing. We did not have data from areas where fishing is not taking place, for example, from coastal waters where reef ecosystems are also present.
To fill this gap in data, a program called Global FinPrint was launched. Collaborating jointly with various institutions in Australia, Canada and the US, they have installed 15,165 underwater video stations in 371 reefs in the territorial waters of 58 countries.
For three years, scientists recorded a total of 18,000 hours of video and then diligently processed it to assess the activity of reef sharks.
They suggested that reef sharks should not have spread to all reefs, but the results were still staggering – almost no sharks were observed with 69 reefs in the territorial waters of six countries; These countries are: the Dominican Republic, the French West Indies, the Carpathian Islands of the Netherlands, Kenya, Qatar and Vietnam.
“In these countries, only three sharks have been observed in 800 hours of observation,” said Colin Simpfendorfer, a marine biologist at James Cook University in Australia.
According to him, this does not mean that sharks are never with these reefs, but it may mean that they are “functionally extinct”, ie they do not play their normal role in the ecosystem.
Sharks play an incredibly important role in the world’s oceans. By destroying weak individuals, populations of prey species maintain health; At the same time, they maintain biodiversity under the control of other species.
However, sharks reproduce very slowly and give birth to relatively small numbers of carnivores. If they competed only with other species of sea, this figure would be wonderful and they would maintain a delicate balance. But such slow-breeding species are extremely vulnerable to overfishing by humans, and population recovery takes a very long time.
When the group compared the data obtained with human activity, they found that very little shark activity was associated with several problems.
“While our research shows a substantially negative human impact on reef shark populations, it is clear that the main problem lies in overpopulation, destructive fishing, and poor governance,” explains one of FinPrint’s programmers, the University of Florida International. .
According to him, it has also been established that strong populations of sharks can coexist with humans if humans so desire, which means that conservation activities are needed.
Shark activity is above average in some countries, including Australia, the Bahamas, the Federated States of Micronesia, the Solomon Islands, French Polynesia, the Maldives, and the United States. Researchers say there seems to be good governance in these countries and there is good management of shark sanctuaries and reserves.
These may include banning shark fishing, limiting the number of sharks to be caught, and banning some equipment in which sharks are trapped and dying.
However, such an approach would still not be universal. Excessive fishing in some regions is caused by the growing demand for shark fins, as these parts are sometimes considered a delicacy. In some countries, fish is the only food for the poor.