Open Data Insight of the Day

In 2023, a total of 156 fish were caught across the River Rhine and its tributaries, with December being the peak month for catches. The largest fish recorded was a notable specimen measuring 176 cm. In the Rhine, the most frequently caught species was the Alet, with 25 individuals captured. The Wiese saw the Alet as the most common catch as well, with 15 individuals. Meanwhile, in the Birs, the Barbe was the most frequently caught species, with 3 individuals. The catch numbers in the Rhine and Wiese have shown a decreasing trend compared to previous years, while the Birs has remained relatively stable.

When comparing 2023 to previous years, there is a noticeable shift in the seasonality of catches, with December emerging as the peak month, contrasting with September's prominence in earlier years. The species composition has also evolved, with the Alet gaining prominence in the Rhine, replacing the Zander and Egli that were more common in prior years. The overall number of species caught has decreased to 12, the lowest since 2010, indicating a potential reduction in biodiversity. The record length of 176 cm for the largest fish in 2023 is a significant increase from previous years, suggesting that while fewer fish are being caught, some individuals are reaching impressive sizes.