The Mississippi mouth would have already moved to Morgan City if not for the Old River Control Structure.

There's definitely more than one side to this issue. Do be aware that it isn't just this one species affected by this dam though. There are likely dozens or more other species that suffered the same fate. Some of them may not even have been known to science before they disappeared forever. Dams are extremely hard on fish populations. The real shame here though is that there are solutions available to mitigate the interruptions caused by damming rivers. It appears none were taken though.

We have the same issue here in the US. I'm less familiar with dams, so I'll talk about the channelization of rivers to keep them navigable year-round for transportation of goods. The Missouri River used to meander to a much, much greater extent than it does now. It used to move back and forth over the course of hundreds of years between the loess deposits in the Midwest. This created a number of slow-moving backwaters where many species of fish would lay their eggs. The most common example of this is the pallid sturgeon.

With the straightening and taming of the river, they lost most, if not all of their breeding habitat. Capture of individuals that are under 15 years old that are not traceable back to a captive breeding project is essentially unheard of. Even adults which are not tagged and previously used for breeding are few and far between.

If you don't care about fish, how about birds? The Platte river was historically described as a mile wide and an inch deep. It was marshy, slow-moving, and full of sand bars where birds like the Piping Plover made their nests. In order to reduce the flood risk and claim some of that fertile land for agriculture, the stream was directed into a much narrower and straighter path. With more water flowing down a narrower channel, sandbars became much less common and were at much higher risk of being washed over, taking eggs and chicks with them. The interior population of the plover was drastically reduced. At the same time, the population on the eastern seaboard were being displaced from their dunes along the Atlantic Ocean. People like the beach, like living there and like playing in the sand. That habitat was taken over by homes and businesses and what was left semi-natural was used for recreation and the birds could no longer safely nest there.

Human use and animal use have to be balanced. Relatively few species can thrive directly alongside humans, but humanity isn't going anywhere any time soon either. It's not the fault of the 9-year-old who wants to run through the dunes that these animals are disappearing, but we still need to keep a certain amount of nature in its natural state so that we don't lose even more of our native species.

Dams are necessary in some cases to keep homes from flooding. However there's got to be a better solution that damming a river completely and building in what used to be valuable habitat.