Overfishing and pollution threaten accelerated loss of ocean species, ecosystems and humans’ food supplies, US and Canadian researchers reported in the November 3 issue of the US journal Science.

"Our analyses suggest that ‘business as usual’ would foreshadow serious threats to global food security, coastal water quality and ecosystem stability, affecting current and future generations," the international team of ecologists and economists wrote in the most exhaustive study to date of the subject.

The four-year analysis was the first to study all existing data on ocean species and ecosystems and synthesize them in an attempt to understand the importance of biodiversity at the global scale.

"Whether we looked at tide pools or studies over the entire world’s ocean, we saw the same picture emerging," lead author Boris Worm of Dalhousie University, in Canada, said in a statement.

Worm said the disappearance of species from ocean ecosystems had been accelerating.

"Now we begin to see some of the consequences. For example, if the long-term trend continues, all fish and seafood species are projected to collapse within my lifetime — by 2048," Worm said.

"In losing species we lose the productivity and stability of entire ecosystems. I was shocked and disturbed by how consistent these trends are — beyond anything we expected."

At this point, 29 percent of currently fished species were considered "collapsed" in 2003, that is, their catches had declined by 90 percent or more, he said.

"It is a very clear trend, and it is accelerating," he said.

The study, "Impact of Biodiversity Loss on Ocean Ecosystem Services," revealed that the loss of marine biodiversity hurt so-called ecosystems services, the goods and functions essential for a growing human population.