Animal deaths in cold weather

Hundreds of fish dead in pond at Linz University

(Bild: Groh Klemens)

Hundreds of dead fish have been floating in the pond at Johannes Kepler University Linz for days. The cause of the animal deaths is likely to have been the freezing cold of the past few weeks. It is mainly ornamental fish and goldfish that have not survived the icy temperatures. They had apparently been released illegally. 

The extent of the tragedy in Linz's Uniteich only became apparent with the current milder temperatures. As the layer of ice melted, it became clear that hundreds of fish had died in the pond, which covers more than 11,000 square meters.

Released illegally
However, most of the victims of the cold were goldfish or ornamental fish that had apparently been released there illegally by aquarium owners. "The pond was drained, dredged and cleaned in 2015. After that, we did not introduce any more fish," emphasizes Vice-Rector Alexander Freischlager.

(Bild: Chri Komposch)

In addition to small aquarium fish, there are also supposed to be koi carp in the facility. However, these did not fall victim to the fish mortality. "The small species - mainly silver-colored Caribbean fish with blue and green stripes - probably froze to the ice cover and died, while the larger ones were probably spared because they are at a different water depth," says the vice rector.

Food for birds
The fish carcasses are now to be collected and disposed of. However, some have already been eaten by birds. Freischlager: "Among others, a flock of seagulls has been spotted."

To be on the safe side, the university has also ordered water samples to clarify whether there may have been any questionable bacterial quality.