An international panel of marine experts warns in a report released this week that the world’s ocean is at high risk of entering a phase of extinction of marine species “unprecedented in human history.”
Two reasons for a “new extinction event” are overfishing and pollutants such as flame retardant chemicals and detergents.
The report (http://www.stateoftheocean.org/ipso-2011-workshop-summary.cfm)
released by the International Program on the State of the Ocean arises from an interdisciplinary international workshop which considered the cumulative impacts of all stressors affecting the ocean.
Considering the latest research across all areas of marine science, the workshop examined the combined effects of pollution, acidification, ocean warming, overfishing and hypoxia, or deoxygenation.
The panel concluded:
-- The combination of stressors on the ocean is creating the conditions associated with every previous major extinction of species in Earth’s history.
-- The speed and rate of degeneration in the ocean is far faster than anyone has predicted.
-- Many of the negative impacts previously identified are greater than the worst predictions.
-- Although difficult to assess because of the unprecedented speed of change, the first steps to globally significant extinction may have begun with a rise in the extinction threat to marine species such as reef-forming corals.
“The findings are shocking,” said Alex Rogers, scientific director of the IPSO. “As we considered the cumulative effect of what humankind does to the ocean the implications became far worse than we had individually realized.
“This is a very serious situation demanding unequivocal action are every level,” Rogers said. “We are looking at consequences for humankind that will impact our lifetime, and worse, our children’s and generations beyond that.”
Marine scientists from institutions around the world had gathered at Oxford University to review recent research by world ocean experts. The report says the scientists “found firm evidence that the effects of climate change, coupled with other human-induced impacts such as over-fishing and nutrient run-off from farming, have already caused a dramatic decline in ocean health.”
The scientists say that increasing hypoxia and anoxia (absence of oxygen, known as ocean dead zones) combined with warming of the ocean and acidification are the three factors which have been present in every mass extinction event in Earth’s history.
There is strong scientific evidence that these three factors are combining in the ocean again, says the panel, exacerbated by multiple severe stressors. The panel concluded that “a new extinction even was inevitable if the current trajectory of damage continues.”
The panel pointed out examples of this “current trajectory” that include:
--- The rate at which carbon is being absorbed by the ocean is already far greater now than at the time of the last globally significant extinction of marine species, some 55 million years ago, when up to 50 percent of some groups of deep-sea animals were wiped out.
--- A single mass coral bleaching event in 1998 killed 16 percent of all the world’s tropical coral reefs.
--- Overfishing has reduced some commercial fish stocks and populations of bycatch species by more than 90 percent.
--- New science also suggests that pollutants including flame retardant chemicals and synthetic musks found in detergents are being traced in the Polar Seas, and that these chemicals can be absorbed by tiny plastic particles in the ocean which are in turn ingested by marine creatures.
The scientists said that adding these and other threats together means that the ocean and the ecosystem within it are unable to recover, being constantly bombarded with multiple attacks.
The report includes a series of recommendations and calls on states, regional bodies and the United Nations to enact measures to “better conserve ocean ecosytems” and demand “the urgent adoption of better governance of the largely unprotected high seas which make up the majority of the world’s oceans.”