In 2021, eight species of freshwater mussels – reliant on healthy, flowing streams – were declared extinct by the U.S. Fish and Wildlife Service.

So were two species of freshwater fish, and eight Hawaiian birds. Another fish will soon make the list.

Nearly a third of all freshwater fish worldwide, science tells us, are threatened with extinction. Sturgeon – one of the oldest families of fishes, having lived on the planet for more than 250 million years – are more critically endangered than any other group of species in the world. In North America, freshwater mussels are most imperiled of all.

Clearly, the world’s biodiversity crisis is most acute in freshwater ecosystems, and all of us need to look around us for actions we can take locally. Along the Hudson River, we have an enormous opportunity we’re just beginning to seize. We can remove obsolete, forgotten dams, numbering more than 1,700, that were built along streams feeding the Hudson centuries ago that are fragmenting habitat, inhibiting genetic diversity, and quietly stifling life in the water every single day.

We’re just beginning to see results – with life returning to Quassaick Creek, Furnace Brook and Wynants Kill after dams were removed. These were the first three projects in our new, landmark effort in New York State. You can learn more about our dam removal effort by visiting this page and signing up here to receive updates.

As we take stock of our achievements, we need to understand the scale of loss.

The number of freshwater organisms that have gone extinct in the past 100 years in the United States is now approximately 150 species. Millions of years of evolutionary adaptations made these creatures finely tuned for very particular habitats – but did not prepare them to withstand human destruction of their waterways. In my opinion, the total destruction of the Louvre and all its contents would not compare to the loss of these species and their alleles that are permanently lost from the gene pool.

Below are the 11 freshwater species listed by USFWS that will never ever be seen alive again:

• San Marcos gambusia (fish) – Range: Texas. Reason: dewatering of rivers.

• Scioto madtom catfish – Range: Ohio. Reason: agricultural runoff.

• Maryland darter (fish, to be listed soon) – Range: Maryland. Reason: dams, agricultural pollution, and sedimentation.

• Yellow-blossom pearly mussel – Range: Tennessee & Alabama. Reason: dams and pollution.

• Upland combshell mussel – Range: Georgia, Alabama & Tennessee. Reason: dams and pollution.

• Tubercled-blossom pearly mussel – Range: Ontario south in 7 states. Reason: dams, pollution from coal mining, logging, and agriculture.

• Turgid-blossom pearly mussel – Range: Alabama, Tennessee, and Arkansas, Reason: dams

• Stirrupshell mussel – Range Alabama & Mississippi, Reason: dams, river channelization, and sedimentation.

• Southern acornshell mussel – Range: Georgia, Alabama, & Tennessee, Reason: dams.

• Green-blossom pearly mussel – Range: Tennessee and Virginia, Reason: dams.

• Flat pigtoe mussel – Range: Mississippi and Alabama, Reason: dams, canals and locks.

It’s difficult to overstate the damage caused by dams. The Chinese paddlefish, up to 21 feet long, was officially declared extinct in 2020, and its loss can be attributed to a single hydroelectric dam, the Three Gorges Dam on the Yangtze River. The Three Gorges Dam also caused the extinction of the Baiji, one of only four species of freshwater dolphins. All other freshwater dolphins species are now critically endangered and threatened with extinction, mostly due to hydroelectric dams. The American paddlefish is also threatened throughout its range, due to overexploitation and damming.

All freshwater megafauna (weighing more than 66 pounds) have declined by 94 percent in the last 50 years. Migratory fishes have declined by 76 percent in the same time period.

Let’s face up to the damage done, and prioritize the life we still can save.

Media contact: Leah Rae, lrae@riverkeeper.org