Coral reefs and the vital ecosystem they provide to oceans, fish and humans have halved since the 1950s, A new study has found.
Scientists at the University of British Columbia (UBC) in Canada have collected a range of coral reef survey and fishing data to assess the impact the world’s declining coral is having on food webs and ecosystems.
The researchers found that the massive loss of live coral coverage in the oceans – about 50 percent since the 1950s – is matched by a similar decline in the “ecosystem services” these reefs offer.
“Coral reefs are known to be important habitats for biodiversity and are particularly vulnerable to climate change, as ocean heat waves can cause bleaching events,” said Tyler Eddy, the scientists involved. one of.
“Coral reefs provide important ecosystem services to humans through fisheries, economic opportunities, and protection from storms.”
The study shows that fishing by coral reefs peaked about 20 years ago and has been declining since then, even as efforts to remove fish from these parts of the ocean have increased.
Along with the total number of fish that have fallen, the diversity of different species living on the reefs has also declined by more than 60 percent.
“Our analysis indicates that the ability of coral reefs to provide ecosystem services has declined by about half,” said William Cheung, a professor at the UBC Institute for the Ocean and Fisheries and senior author of the research. “This study highlights the importance of how we manage coral reefs, not only on a regional scale, but also on a global scale, and the livelihoods of the communities that depend on them.”
Coral reefs, which are made up of tiny organisms called polyps, cover only about one percent of Earth’s surface, but are important building blocks of a healthy marine ecosystem. By providing food and habitat for breeding and nursery grounds, they support about 25 percent of all marine life, including more than 4,000 species of fish.
They benefit humans not only by nourishing the fish consumed by millions, but also by protecting shoreline communities from waves and storms.
However, coral is under threat around the world, mainly due to climate change. Rising ocean temperatures cause tiny algae called zooxanthellae – which provide most of the coral’s food and nutrients – to be expelled from their hosts which in turn slowly kills the reef, against its normal form. Turns vibrant colors into a dull white.
This bleaching of coral reefs transforms them from an important life support system for marine life to a marine graveyard.
The study’s authors also warn indigenous coastal human communities that rely on coral may be at risk from the ongoing erosion of the world’s reefs.
“Fish and fisheries provide essential micronutrients in coastal developing regions with few alternative sources of nutrition” they wrote. “Coral reef biodiversity and fisheries take on additional importance for indigenous communities, small island developing states and coastal populations where they may be essential to traditions and cultural practices.
“The diminished capacity of coral reefs to provide ecosystem services undermines the well-being of millions of people with historical and ongoing relationships with coral reef ecosystems.”
Credit: www.independent.co.uk /