Swimmers’ Urine Blamed for 500 Fish Deaths in Germany
OutdoorHub Reporters 05.23.12
There’s something in the water, something killing scores of fish. As many as 500 fish have been found dead in picturesque Eichbaum Lake near Hamburg in northern Germany. German researchers believe it’s because of an exorbitant amount of urine in the lake from swimmers.
There’s a reason your mother told you to never pee in the pool, or lake, in this case.
“Swimmers who urinate in the lake are introducing a lot of phosphate,” which can contribute to algae blooms, according to Manfred Siedler, spokesman for the Hamburger Angling Association (ASV). “We’re calculating half a liter (about 1 pint) of urine per swimmer per day,” he told Bild newspaper. It’s postulated that urine could have led to the build up of blue-green algae in the lake’s eco-system which subsequently poisoned the fish.
The ASV has long been feuding with lake swimmers, according to The Local, an online news website that publishes German news in English. Swimmers are currently banned from the lake. Hamburg’s Urban Development and Environment Authority (BSU) is working to reopen the lake before summer.
When io9 heard about this, they asked themselves, “can peeing in a lake really kill fish?” In fact, it can. Urine has three essential nutrients, nitrogen, potassium and phosphorus, that aid plant growth. These are actually the three main ingredients in industrial and natural fertilizers.
Adding this to lakes is like essentially dumping fertilizer in the ecosystem. This causes the algae to boom and in turn the algae suck up much of the available oxygen underwater. That robs the fish of their oxygen supply.
Other scientists blame another human activity for the death of the fish: ice skating. “The ice-skaters make a noise that wakes the fish out of hibernation,” BSU spokeswoman Kerstin Graupner told the Local. “Then they can’t breathe and freeze. That’s a very common phenomenon,” suggesting that only now the bodies of fish that died in the winter are being found.
Attempts to introduce an anti-phosphate agent into the lake have been unsuccessful and cost the state a reported 516,000 Euro (USD $667,000). For now, the lake remains closed to bathers.
