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ScienceShot: Sawfish Going Extinct

The vast sandy channels and grassy flats of Brazil’s Amazon estuary may be the last, best hope for the beleaguered largetooth sawfish (Pristis pristis) in the Atlantic Ocean. The swimmer, known for its long, tooth-edged snout that looks like some alien saw blade, is one of the world’s most threatened marine creatures, a victim of overfishing and habitat loss. The shark relative is found around the world in tropical and semitropical seas, but in recent years conservationists have become gravely concerned about Atlantic stocks. The fish may now be extinct in some parts of its Atlantic range, including waters off the southern United States, northern South America, and southern West Africa, researchers report in Aquatic Conservation: Marine and Freshwater Ecosystems. And an analysis of more than 800 sightings and catch records from 1830 to 2009 suggest that just three sawfish strongholds remain in the Atlantic: the Colorado-San Juan River system in Nicaragua and Costa Rica, the Bissagos Archipelago in Guinea-Bissau, and—most important—the Amazon estuary. Greater protection for these areas is “crucial,” the authors conclude, “if the extinction of the species in the Atlantic Ocean is to be prevented.” 

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