Overfishing is driving coral reef sharks toward extinction

Overfishing is driving coral reef sharks toward extinction

Subject :Environment

Section: Species in news

Context:

• Five of the most common shark species living in coral reefs have declined 60% to 73%, according to a massive global study by Colin Simpfendorfer and colleagues.
• The research is a result of a worldwide collaboration called the Global FinPrint project and was funded by the family foundation of Microsoft co-founder and ocean enthusiast Paul G. Allen.

Details of the study:

• Some individual shark species were not found at 34% to 47% of the reefs in the survey.
  • The likely cause is overfishing, which has removed both the sharks themselves and the prey they depend on.
• As shark numbers decline, ray species are increasing on the reefs, suggesting a shift in the top elasmobranch species in the communities.
• 391 coral reefs in 67 nations and territories using 22,756 remote underwater video stations.
  • They show that shark-dominated reefs persist in wealthy, well-governed nations and in protected marine sanctuaries.
  • In areas of poverty and limited governance, rays dominate the reef communities.
• The estimated declines of these resident reef shark species meet the IUCN Red List criteria for Endangered status.
• As the top predators of the reef and indicator species for marine ecosystems, they help maintain the delicate balance of marine life in reef environments.  Reef sharks are highly valued for their meat, leather, liver oil, and fishmeal, which make them prone to overfishing and targeting. Yet, their importance for the tourism industry makes them more valuable alive than dead. In 2011, Honduras declared its waters to be a permanent sanctuary for sharks, making fishing for these species completely forbidden.
• It focused on five key species of reef sharks — the Caribbean reef shark, nurse shark, grey reef shark, blacktip reef shark and whitetip reef shark — by collecting and analysing 22,000 hours of video footage.
• The study showed that the five species would qualify as endangered on The International Union for Conservation of Nature Red List of Threatened Species. The IUCN is the global authority on nature conservation.