Environment - Dead fish in several Alster canals
The fish die-off in the Alster has spread to further channels. Hundreds of fish have died in the past few days due to lack of oxygen caused by heavy rains. Initially, only the Osterbek canal was affected by the massive fish die-off. Now, numerous dead fish are floating on the surface of the Isebek canal and the Mundsburger canal. Since Monday, employees of the Landesbetrieb Straßen, Brücken und Gewässer (LSBG) have been removing the animals from the water, as the environmental agency announced. Due to the heavy rain, large quantities of organic matter - including pollen, dust, soil, and feces - have been washed into Hamburg's waters. The biological breakdown of these organic inputs in combination with already elevated water temperatures can lead to a oxygen deficiency that can be fatal for fish.
If temperatures rise significantly in the coming days or if there are further heavy rainfalls, the oxygen content in the water will not improve and more fish will die, warned the Landesbetrieb. Due to the large number of dead animals, the fishing operation may last several more days. The Landesbetrieb can only determine exactly how many dead fish there are in the coming days.
The die-off of fish isn't limited to the Alster and Osterbek canals anymore; the Isebek and Mundsburger canals are also affected, suffering from a similar lack of oxygen due to the influx of organic matter from the weather. Despite the efforts of the Landesbetrieb Straßen, Brücken und Gewässer to remove dead animals from the water, the high fish mortality rate indicates a significant impact on Hamburg's animal population in the water environment. The ongoing heavy rainfall and potential future temperature rise could potentially exacerbate the existing oxygen deficiency, posing a threat to the survival of remaining aquatic life in the canals.
