Study: Overfishing is driving reef sharks to extinction
A worldwide research released on Thursday indicates that coral reef sharks are in far greater danger than previously believed and are being driven into extinction as a result of overfishing. That is significant to humans because they regulate their marine ecosystems by keeping the precisely balanced food webs that support hundreds of millions of people in place.
The Global FinPrint project, which gathered more than 22,000 hours of video from reefs in Africa, the Middle East, Asia, Australasia, and the Americas, produced the study, which was then published in the journal Science.
Five of the most prevalent coral reef shark species, including the grey reef, nurse, Caribbean reef, blacktip reef, and whitetip reef, have seen declines of between 70 and 60 percent, according to a group of more than 100 experts.
The depletion data came from a computer model that predicted shark populations in the absence of human forces.
In 14% of reefs where sharks had previously been recorded, they were completely missing.
Contrary to their larger counterparts that live in deep waters, coral reef sharks were not regarded to be in poor health prior to the research, according to lead author Colin Simpfendorfer of the James Cook University and the University of Tasmania.
However, he said, “it was quite stunning when you sat down and looked at the overall results.”
impact waves
More species should now qualify for “endangered” classification on the IUCN Red List as a result of the results, which is a crucial first step in taking conservation action.
According to Simpfendorfer, overfishing, which kills sharks inadvertently as bycatch as well as purposely for their flesh and fins, is the primary cause of the drop.
Shark extinction has an influence that extends farther up the food chain.
The amount of the prey they consume rises, while the prey below them declines, and so on, causing unexpected disturbances that endanger human food security.
Reef sharks also control herbivore populations, according to Simphendorfer. As herbivores proliferate, they consume more algae, which sequester carbon for use in photosynthesis.
According to him, there is an effect on global warming since carbon sequestration on coral reefs without sharks is substantially lower than it is on reefs with sharks.
rays of hope
The Paul G. Allen Family Foundation, which oversaw the Great Elephant Census, an airborne survey of the biggest terrestrial mammals on Earth, provided funding for the undertaking.
In the shark investigation, researchers deployed baited remote underwater video stations (BRUVS)—cameras with a tiny quantity of oily fish hanging put on arm—for deployments that lasted an hour—to attract and watch sharks.
They used 22,756 cameras to examine 391 coral reefs in 67 countries and territories, producing enough raw footage to last three years.
more income nations with stricter laws and more levels of democratic engagement often have reefs with healthier inhabitants, whereas lower income nations typically have poorer results.
The researchers did find several “hope spots” nevertheless, like Sipadan Island in Malaysia and Lighthouse Reef in Belize.
According to co-author Michael Heithaus of Florida International University, “in and around them, things are fairly depleted, but in those areas where you have strong MPAs (marine protected areas) and really good ways to enforce them, you have robust shark populations.”
According to him, this gave rise to optimism that severely depleted places might be repopulated if a source population was still there and stringent management procedures were followed.
