The Yangtze Finless Porpoise

Two numbers, written on two different sheets of paper, a few years apart.

The most recent time people went out to count along a very long river, the number they wrote down was 1,426. The count before that came to 1,249.

Those two numbers say something very strange. The newer number is the bigger one. It is bigger by exactly 177.

For an animal that is growing rarer around the world, that almost never happens. Each count is usually lower than the one before, and the next is lower still. Yet on this river, it went the other way.

The animal being counted is the finless porpoise, and its home is the Yangtze.

It does not live out at sea. It lives in fresh water, along the middle and lower stretches of the river, and in two large lakes joined to it, Poyang Lake and Dongting Lake. Poyang is the largest freshwater lake in China. In the whole family of finless porpoises, this is the only branch that lives entirely in fresh water and never once reaches the salt sea.

Once seen, it is never forgotten. On its back there is no tall upright fin like the dolphins in pictures. Instead there is only a low ridge, raised into a row of small, rough bumps, as if someone had stitched a seam down its spine. Its head is round, with no pointed snout and no long beak. The largest ones grow up to 2 meters long and weigh up to 100 kilograms.

But what makes people love it most is its mouth. It curves up a little at both corners, and has since birth, so from any angle the face seems to be smiling. People in China call it by a very tender name: the smiling angel of the Yangtze.

It smiles in murky water. Below that surface its eyes are almost no help, so this animal does not find its way by sight. It sends out very short clicks, far higher than the human ear can hear, then falls quiet and listens for the echo coming back. The echo tells it whether what lies ahead is a log, a sandbank, or a school of swimming fish. In other words, it sees with its ears.

It is not a fussy eater at all. Inside the stomachs of these porpoises, people have found at least 20 different kinds of fish, along with shrimp and a few kinds of shellfish. As long as there are fish, it eats its fill.

Counting an animal like this is enormously hard. It is small, and it has no fin on its back for anyone to spot from far away. Each time it comes up, it takes exactly one very quick breath and slips under again. Among all the mammals that live in water, this is one of the hardest to observe by eye.

This animal has lived in the middle and lower Yangtze for a span of time that is hard to imagine. Its ancestors came in from the sea hundreds of thousands of years ago. The river has changed its bed again and again, banks have built up and crumbled away, and villages have risen and moved on. And still those round backs come up to breathe in the middle of the current, just as before.

Then comes the hard part of the story.

The counting sheets of the past were not happy ones. In 2017, people counted across the whole river basin and recorded 1,012 porpoises. Every time it was the same, a new count found fewer. Year by year the river grew busier with boats and noisier, and year by year the fish in it grew scarcer. For an animal that sees with its ears, a noisy river is a dark river. For an animal that lives on fish, a river without fish is a hungry river.

Then something happened that sounded too simple to make any difference at all.

From the first day of 2021, fishing on that river stopped. Not for a single season. Not on just one stretch of the river. It stopped along the whole river, and it stopped for ten straight years. The nets were rolled up out of the water and left on the shore.

Ten years is a very long time in the life of a fish. A fish left in peace long enough grows up and has young of its own, and those young have young in turn. When the fish come back, the animals that eat fish come back too. The river slowly fills up again, from the bottom up, starting with the smallest creatures that nobody notices.

In 2022, people went out to count again, exactly five years after the count before. The number they recorded was 1,249.

It was the first time since counting began that the number had gone up instead of down.

At the next count, in 2025, the number rose to 1,426. That was 177 more than the time before. Once again, the newer sheet was the one with the bigger number.

That does not mean the animal is safe now. It is still listed as critically endangered. For a vast river and two large lakes, 1,426 porpoises is still far too few. The ten years without fishing are not over yet either. This story has not ended. It has only turned around.

But that turn can be seen with the naked eye. In the city of Nanjing, where the Yangtze runs right through town, people now see them quite often in the stretch of river inside the city. A round back rises out of the water, there is a soft breath, and then it is gone. Anyone on the bank who catches it in time remembers it for a long, long time.

A porpoise or dolphin living in a river can sound like the story of some faraway river. But the great river that flows into Vietnam has river dolphins of its own.

The Mekong, which in Vietnam takes the name Cửu Long, has a freshwater dolphin too. It is called the Irrawaddy dolphin. It also has a round head and no pointed beak, and it looks like a distant cousin of the animal in the Yangtze. Today those dolphins live on a stretch of the Mekong in Cambodia, upstream from the area of Kratie. That is about 500 kilometers from where the river meets the sea in Vietnam. Long ago, they ranged much farther down, all the way to the Mekong Delta.

So the word dolphin need not bring only the sea to mind. There are dolphins that never taste a single mouthful of salt water in their whole lives, and yet they thrive in the fresh water of a river.

And now, back to the two sheets of paper from the beginning.

The bigger number sits on the newer sheet, after a very long river was given a rest from fishing, a ten-year rest that has not yet ended. The fish came back first. Then came the round, glossy backs, rising in the middle of the current for one short breath, carrying a mouth curved from birth into a smile, then sinking quietly back into the murky water.