In the 1950s, thousands of Baiji river dolphins (pictured) plied the waters of the Yangtze, Asia's mightiest river. The Chinese river dolphin had evolved over 20 millions of years, and was revered as the goddess of the Yangtze. By 1994, fewer than 100 individuals remained, and by 2006, the dolphin had become extinct. A proud branch on the tree of life had been destroyed in the blink of an eye by pollution, dam building, and reckless navigation.
Sadly, the goddess of the Yangtze is not alone in her fate. The last Chinese paddlefish was sighted in 2003. The majestic Chinese sturgeon is considered to be critically endangered as well. Of the 143 fish species that were historically recorded in the Yangtze River, only 17 were left in 2013.
As many as 30 million animal, plant and fungi species populate Planet Earth. About 1.7 million of them have been identified and described. What is the health of these plant and animal kingdoms? Which species groups are at particular risk? Are the extinct Chinese river dolphin and paddlefish only the tip of an iceberg?
The most comprehensive scientific source of information on the conservation status of the world's biodiversity is the IUCN Red List of Threatened Species. Prepared by experts groups of the IUCN, the Red List has rigorously documented the status and the threats to animal, plant and fungi species for 50 years. The assessment serves as a critical source of information for International Rivers' interactive database, The State of the World's Rivers, and many other surveys and reports.
According to the 2014 Red List, 22,176 of the 74,108 species that have been evaluated are threatened by extinction. Of the 11,323 evaluated fish species, 2,172 are considered under threat. These figures are not necessarily representative in that assessment efforts focus on species more likely to be threatened. On the other hand, countless species have likely been extinct before they were ever identified or assessed.
Even with the limited information available, we know that freshwater ecosystems are extremely rich in biodiversity, and more threatened by species extinction than any other major ecosystem. The Red List considers 41% of all amphibians and 31% of all freshwater crabs threatened, and in 2009 classified 37% of the evaluated freshwater fishes as threatened. For example, no less than 24 of the planet's 26 sturgeon species are threatened or near-threatened. As the Global Biodiversity Outlook found in 2010, rivers, lakes and other wetlands "have undergone more dramatic changes than any other type of ecosystem" due to dam construction, drainage, water diversion and pollution.
The IUCN Red List offers a much-needed annual check-up on the ecological health of our planet. It provides important guidance on how we can protect the building blocks of life on Earth, in ways that are often less costly than the long-term impacts of biodiversity loss. We celebrate the 50th anniversary of this invaluable tool, and salute Synchronicity Earth and the other funders who are making this service possible.
We are well-advised to listen to our doctors. Shouldn't we pay more attention to our planet's ecological health check-ups as well? Dr. Richard Sneider, Global Chair of the IUCN Freshwater Fish Specialist Group, warns: "Most heart attacks are the result of a blockage of arteries. Blocking or disrupting river flows have the same effect on the planet as they do in the human body. Unless we are becoming much more proactive in addressing the alarming incremental pace of river flow disruption, we are likely to give the planet a heart attack with seriously crippling and devastating consequences to all life on earth!"
The Chinese river dolphin has disappeared before our eyes within only two generations. Will we change course before other branches on the tree of life die off? It would be foolish to assume that we can somehow maintain our prosperity and our very future without the rich biodiversity on Planet Earth.