#yangtze

"China has demolished 300 dams and shut down most of the small hydropower stations on a major tributary of the upper Yangtze River to safeguard fish populations as part of an effort to restore the ecology of Asia’s longest waterway.

According to a report by the state news agency Xinhua on Monday, 300 of the 357 dams on Chishui He – also known as the Red River – had been dismantled by the end of December 2024.

In addition, 342 out of 373 small hydropower stations have been decommissioned, enabling many rare fish species to resume their natural reproductive cycles, the Xinhua report said.

The Red River flows for more than 400km (249 miles) through the southwestern provinces of Yunnan, Guizhou and Sichuan. It is regarded by ecologists as the last refuge for rare and endemic fish species in the Yangtze’s upper reaches.

Over the decades, water flows have been increasingly blocked by the dense network of hydropower stations and dams, restricting water volumes downstream and occasionally even causing some sections to dry up entirely.

This has drastically reduced the amount of suitable habitat and spawning grounds. The stations also blocked the routes of migratory fish species between breeding grounds and non-breeding areas.

Zhou Jianjun, a professor of hydraulic engineering at Tsinghua University, said that the decommissioning of hydropower stations usually referred to the cessation of electricity generation.

“The key is not whether the facilities still exist, but that, after power generation stops, the method of water control can be changed to meet ecological needs,” he said.

According to the Xinhua report, the large-scale rectification work that began in 2020 has meant that aquatic wildlife species, including the Yangtze sturgeon, have regained their habitat and vitality.

Along with the Chinese paddlefish, the freshwater sturgeon species – known as the last giant of the Yangtze – was declared extinct in the wild by the International Union for Conservation of Nature in 2022.

The natural population of the sturgeon has declined sharply since the 1970s, largely as a result of dam construction and the development of a shipping industry in the Yangtze River.

No naturally bred young sturgeon had been found in the entire Yangtze River since 2000, but a team of scientists from the Chinese Academy of Sciences’ Institute of Hydrobiology has reported promising signs of recovery, according to Xinhua.

The team, led by Liu Fei, a researcher at the institute in Wuhan, released two batches of Yangtze sturgeon into the Red River in 2023 and 2024, which have successfully adapted to the wild environment and are thriving.

This year, the researchers decided to take it a step further and examine whether the fish could migrate naturally for reproduction. In April, they released 20 adult Yangtze sturgeon into a section of the river in Guizhou.

By mid-April, they observed the fish displaying natural spawning behaviour and successfully hatching fry, the researchers said.

“This achievement indicates that the current ecological environment of the Red River can now meet the habitat and reproductive needs of Yangtze sturgeon,” Liu told the news agency.

According to the institute’s latest monitoring results, the Red River’s aquatic biodiversity is steadily improving, with a significant increase in the number of fish species collected in various sections of the river.

China has launched a series of policy measures to protect the Yangtze’s critical role as an aquatic habitat, all centred on a 10-year fishing ban imposed in 2020 and the regulation of the small hydropower stations that have affected its biodiversity.

For example, by the end of 2021, Sichuan had essentially finished rectifying its 5,131 small hydropower stations, which included shutting down 1,223 of them, according to a local official report the following year.

The local government has also strictly prohibited sand mining in the rivers in a bid to create a more favourable environment for aquatic animals to breed and reproduce.

In a communique released in August last year, Beijing announced that aquatic biodiversity had steadily improved since the fishing ban and other measures were introduced.

Fish, invertebrates and amphibians continued to recover, while the overall water quality of the Yangtze and its tributaries was rated as “excellent”, it said. The intensity of sand mining and other projects affecting fisheries had also decreased.

(credit in the video)

So on Lake Taft in Richland, Minnesota, two people collecting water quality samples. Those two people were Kate Lucas and Kevin Menken, who work at Barr Engineering.

According to Lucas, she saw a small translucent blob alongside their canoe, and she knew it was a jellyfish right away. She got excited and told Menken about it, and proceedes to collect pictures of the specimen.

Once more, these are jellyfish from China, similar to the ones found in Iowa that I reported on last year.

This isn't the first confirmed spotting in Minnesota, as there have been other sightings, however this is the most recent one.

To delve deeper into the jellyfish found, it's the peach blossom jellyfish (scientific name craspedacusta sowerbii) which is native to the Yangtze river found in China. This species of jelly eat microfauna, so that would include animals like zooplankton for example.

This species is too small to harm people as they are simply too little. They're ~20/22 mm in diameter and their tentacles, while having stinging cells, lack the ability to pierce human skin.

They have been found quite literally around the globe, found on every continent, excluding Antartica.

Another notable example was Lake Erie, ome of the great lakes in North America. Examples outside North America include the Moscow River in 2010 and Lake Burley Griffin in Australia.

The Chinese paddlefish was the world's largest freshwater fish, a species that has survived since the age of dinosaurs. However, no surviving individuals have been found since 2003, and it was declared extinct by the International Union for Conservation of Nature (IUCN) in 2022.

The main reason for the extinction of the Chinese paddlefish is the impact of dam construction. The construction of huge dams in the Yangtze and Yellow River basins in China, which used to be their habitat, have created no upstream passage for the fish, and they can no longer go upstream to their spawning grounds. It is believed that the population of the Chinese paddlefish has continued to decline because they can no longer spawn safely.