for National Geographic News
Unless humans act now, seafood may disappear by 2048, concludes the lead author of a new study that paints a grim picture for ocean and human health.
According to the study, the loss of ocean biodiversity is accelerating, and 29 percent of the seafood species humans consume have already crashed. If the long-term trend continues, in 30 years there will be little or no seafood available for sustainable harvest.
The increasing pace of diversity loss thus imperils the "ecosystems services" that many human populations depend on for survival, the study says.
The research also found that biodiversity loss is tightly linked to declining water quality, harmful algal blooms, ocean dead zones, fish kills, and coastal flooding. (Related: 'Dead Zone' off Oregon Coast Is Growing, Study Says" [August 4, 2006].)
"Biodiversity is a finite resource, and we are going to end up with nothing left ... if nothing changes," said Boris Worm, an assistant professor of marine conservation biology at Dalhousie University in Halifax, Canada.
Worm led the international team of scientists and economists that examined the role of marine biodiversity in maintaining ecosystem services. The research appears in tomorrow's issue of the journal Science.
But areas managed for improved biodiversity can and do recover, Worm says, raising the possibility that the trend can be reversed if humans take action.
"Where we [protect marine areas] around the world—from the tropics to temperate ecosystems—we see an increase in species diversity and productivity and stability and economic revenue from those ecosystems," he said.
Worm and colleagues examined the impact of species loss at local, regional, and global scales and in a variety of ecosystems.
Everywhere they looked, they got the same result: The greater the loss of diversity, the greater the impact on ecosystem services.
"Ecosystems that were losing species were always more fragile, always more vulnerable, always more likely to see a whole collapse of fisheries, more likely to show an increase in toxic events like fish kills and things like that," Worm said.
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