During a trip to China a dozen or so years ago, we visited the Three Gorges Dam, and it was a sight to behold. The straight-crested concrete gravity structure is almost one and a half miles long with a maximum height of 607 feet. The structure incorporates 37 million cubic yards of concrete and 463,000 metric tons of steel. The hydroelectric gravity dam spans the Yangtze River by the town of Sandouping, in Yiling District, Yichang, Hubei province in central China. The Three Gorges Dam electricity generation capacity is the largest in the world. When it comes to infrastructure, the Chinese think big and act big. They don’t let impact studies get in their way.
One of the highlights of our trip was a cruise on the Yangtze River. The river is 3,900 miles long, and the river basin is 698,300 square miles. The basin accounts for 40% of China’s freshwater resources, more than 70% of the country’s rice production, 50% of its grain, 70% of fishery production, and 40% of China’s GDP. Approximately 400 million people live along the Yangtze River and its 700 tributaries.
As the river cruise progressed, I noticed huge wooden chutes extending from hundreds of feet up the shores of the gorge sloping steeply down to near the water. At the top of the gorge were coal preparation plants associated with the coal-burning electric plants. The chutes were used to pour the coal slurry, a mixture of solids and liquids, into the river. Not only did the power plants pollute the environment, but the slurry wreaked havoc with the Chinese sturgeon, a critically endangered species native to China. We stopped in a museum along the river and saw a giant preserved sturgeon.
Fast forward to May 5, 2021 when NPR reported, “A Huge, Ancient Lake Sturgeon Has Been Lurking In The Detroit River”. Three scientists with the U.S. Fish and Wildlife Conservation Office in Alpena, Michigan were doing their annual survey of the lake sturgeon population. After quite a struggle they were able to get a sturgeon in their net and haul it to the deck of their boat. They were amazed at the size of the fish.
The sturgeon turned out to weigh 240 pounds and measured nearly 7 feet long with a girth of nearly 4 feet. The scientists believe the fish is a female and is at least 100 years old. You can see the comparison in the picture of Jennifer Johnson, a member of the survey crew, laying next to the massive sturgeon. The scientists tagged the sturgeon with a microchip and released her back to the river.
Scientists estimate there were more than half a million sturgeon swimming in the Detroit River in the 19th century. At the present time, they believe there are fewer than 7,000 due to overfishing and destruction of habitat. The good news is the scientists believe the Detroit River water has improved vastly during the last few decades. Yangtze River conditions are also said to be improving.
Monitoring the trends of fish movement is important for the long term preservation of species. Researchers at the University of Minnesota, Cedar Creek Bioelectronics Laboratory, were early pioneers of using electronic methods to track wildlife. They went on to form a company, Advanced Telemetry Systems, which specializes in creating sensors, receivers, and tracking equipment for biotelemetry. They make sensors which can be injected, implanted, or attached to fish such as the giant sturgeon in Detroit. The big one got away, but she will be tracked for years to come.