GENEVA – A leading conservation group uniting governments and civil society says all four known freshwater dolphin species are now threatened with extinction, after newly discovered information on the tucuxi in the Amazon river system showed it too is endangered.
The finding from the International Union for Conservation of Nature comes as its latest “Red List” of threatened species, released Thursday, also showed that populations of the European bison — Europe’s largest land mammal — have improved, even as the list of extinct species overall has continued to expand.
“The European bison and 25 other species recoveries documented in today’s IUCN Red List update demonstrate the power of conservation,” said Dr. Bruno Oberle, IUCN’s director-general.
Still, the conservation group said 31 species have been declared extinct in the latest of its regular updates of the list, including three Central American frog species and 15 freshwater fish species endemic to a single lake in the Philippines. A South China Sea shark, last seen in 1934 and only formally described last year, is thought to be “possibly extinct.”
Craig Hilton-Taylor, head of the IUCN red list, said the impact of human activity was a driver for many species nearing extinction.
“All of these things are down to human activities, whether it’s direct hunting or fishing or harvesting of the species, to introducing invasive species, changing habitats to agriculture, urbanization, climate change,” he said in a video interview. “The human footprint is everywhere.”
The tucuxi, a small gray dolphin found in the Amazon River system, is now listed as “endangered.” Its numbers have been severely depleted by human activity, including fishing gear, the damming of rivers and pollution. Previously there wasn't enough information to determine its status.
The Gland, Switzerland-based group cites three other freshwater dolphin species — the Amazon river dolphin, the South Asian river dolphin and the Yangtze River dolphin in China, though it may already be extinct — as threatened, along with the Yangtze finless porpoise, IUCN spokesman Matthias Fiechter said.