Study Fears Mass Extinctions
Mankind is on the brink of causing mass extinctions in the earth's oceans as it has done on land - but if we act promptly disaster can be averted, a new study reports
A review of studies into animal extinctions published in Science this week suggests we are on the verge of triggering mass extinctions across the planet's oceans. A team of American scientists analysed data from hundred of different studies and reported that the threat of such a disaster is accelerating.
'We may be sitting on a precipice of a major extinction event,' said Douglas J McCauley, an ecologist at the University of California, Santa Barbara, one of the report's authors. The report says the loss of animal species in terrestrial environments has been well documented and is continuing. Loss of species in marine environments has been slower than in terrestrial systems, but appears to be increasing rapidly.
But there is still time to avert catastrophe, Dr McCauley and his colleagues also found. Compared with the continents, the oceans are mostly intact, still wild enough to bounce back to ecological health.
'We’re lucky in many ways,' said Malin L Pinsky, a marine biologist at Rutgers University and another author of the report. 'The impacts are accelerating, but they’re not so bad we can’t reverse them.'
The scientists argue that three lessons emerge when comparing the marine and terrestrial defaunation experiences:
- Today’s low rates of marine extinction may be the prelude to a major extinction pulse, similar to that observed on land during the Industrial Revolution, as the footprint of human ocean use widens
- Effectively slowing ocean defaunation requires both protected areas and careful management of the intervening ocean matrix
- The terrestrial experience and current trends in ocean use suggest that habitat destruction is likely to become an increasingly dominant threat to ocean wildlife over the next 150 years.
Dr Pinsky, Dr McCauley and their colleagues pulled together data from an enormous range of sources, from discoveries in the fossil record to statistics on modern container shipping, fish catches and seabed mining. While many of the findings already existed, they had never been brough together in such a way.
The authors did point out that ocean ecosystems remain more wild than terrestrial ecosystems. Consequently, meaningful rehabilitation of affected marine animal populations is still possible.
And they warned that human dependency on marine wildlife and the linked fate of marine and terrestrial fauna necessitate that we act quickly to slow the advance of marine defaunation.