Around 500 fish have died in an algae bloom in a lake in northern Germany â€” and fishermen are blaming swimmers for urinating in the water.
The deaths have occurred in Eichbaum Lake, in the port city of Hamburg.
A spokesman for the local Angling Association said: "Swimmers who urinate in the lake are introducing a lot of phosphate. We're calculating half a litre/0.15 gal. of urine per swimmer per day."
Applying anti-phosphate products to the water has been expensive and hasn't worked, fuelling a long-standing feud between fishermen and bathers in the lake.
Swimming in the lake has now been banned until the algae outbreak has been addressed, but the city's Urban Development and Environment Authority (BSU) is hoping to re-open it to bathers before the summer. It's asking the local university to help test the urine-related fish death theory.
In fact according to a report in the Local, the BSU believes that the fish deaths may have been caused not by swimmers peeing in the water, but by a combination of natural causes and ice skating.
"The ice-skaters make a noise that wakes the fish out of hibernation", a BSU spokesperson said. "Then they can’t breathe and freeze. That’s a very common phenomenon."
Although the fish have only been found in the past two weeks, the level of decomposition suggests they have been dead for some time.
Another report in Bild says that water tests have shown the lake is very alkaline, with a pH level of 8.7.
Scientists have reportedly also found anabaena algae blooms, unusual at this time of year, which produce anatoxin-a. This causes ammonium in the lake to change into the poisonous ammonia, restricting the fish's breathing.
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