| A part of the protected marine area in Papua New Guinea. Image courtesy: ARC COE for Coral Reef Studies/ Marine Photobank
New Delhi, Nov. 2: All marine fish and seafood might collapse by 2048, devastating marine ecosystems and forcing many people alive today to bid goodbye to delicacies from the deep in their lifetime, a study has predicted.
An international team of ecologists and economists who studied global fisheries has found that if current trends of ocean species loss persist, the oceans will cease to serve the human palate by the mid-21st century.
The study, which extracted data on fish and seafood catch from 64 large marine ecosystems worldwide, has predicted the collapse of all species of wild seafood by 2048, a collapse defined as 90 per cent depletion. The study, to appear in the journal Science tomorrow, is being described as the first comprehensive assessment of the world’s marine ecosystems.
“Whether we look at tide pools or the entire world’s oceans, we saw the same picture emerging,” said Boris Worm, a biologist at Dalhousie University in Canada, and lead author of the study. “I was shocked by how consistent these trends are — beyond anything we suspected,” he said. “At this point, 29 per cent of fish and seafood species have collapsed. It’s a very clear trend and it is accelerating.”
But the study has also shown that the trends could still be reversed.
“The good news is that it is not too late to turn things around,” Worm said.
When the researchers examined 48 areas around the world that have been protected to improve marine biodiversity, they found that the diversity of species recovered dramatically.
“The solution appears to be managing fisheries in a holistic way,” Nicola Beaumont, an environment economist at the Plymouth Marine Laboratory in the UK and one of the 14-member research team, told The Telegraph.
Reversing the decline would demand different strategies for different marine ecosystems, Beaumont said.
Possible solutions are: restricting fishing activities to only certain times of the year, changing the fishing gear used, harvesting only specific species in certain areas, and marking vulnerable areas as protected marine reserves.
“Some marine ecosystems have shown their ability to recover within three to five years,” Beaumont said. The study found that closure of fisheries and setting up marine reserves increased species diversity by 23 per cent.
The researchers found that species diversity varied widely across the 64 large marine ecosystems selected for the study — from less than 20 species in some areas to more than 4,000 in others. The fish species diversity in both the Arabian Sea and the Bay of Bengal range between 500 and 1,000 species, according to the study.
It’s not just exploitation of the sea for the human palate that is depleting the world’s fish stocks. Marine pollution, reclamation of the sea, destruction of marine habitats and an increase in the acidity of the ocean caused by rising carbon dioxide in the atmosphere are also contributing to the decline in fish, Beaumont said. “This isn’t predicted to happen. It is happening now.”
The researchers said the impact of ocean species loss goes beyond decline in seafood. Human health risks could emerge as depleted coastal ecosystems become vulnerable to disease outbreaks and noxious algae blooms.
Scientists said humans rely on marine biodiversity in many ways. “The ocean is a great recycler. It takes sewage and recycles it into nutrients and scrubs toxins out of the water, and it turns carbon dioxide into food and oxygen,” said Steve Palumbi, a team member at Stanford University. But to do all this, the oceans need their diversity of millions of plants and animals.
The researchers have said restoring marine biodiversity through pollution control, fisheries management and creation of reserves would be essential to avoid threats to food security and water quality.