From BZ/dpa
Is the catastrophe of last year threatening to repeat itself?
After the discovery of dead fish and the detection of the poisonous golden alga Prymnesium parvum in the water system of the Oder, Poland’s Ministry of the Environment has convened a crisis team.
“Three dead fish – this is already an important warning sign that we need to be on standby and the risk of a repeat of last year’s situation is very high,” Environment Minister Anna Moskwa told Polish public radio on Wednesday. The water temperature of the Oder has risen sharply. “That is the first factor.” The crisis team makes it possible to act quickly, the minister said.
450 kilos of dead fish
At the beginning of the week, according to the regional administration of the Opole Voivodeship, a total of 450 kilograms of dead fish were recovered in the Gliwice Canal branching off the Oder and in the Kedzierzyn Canal. The poisonous golden alga was also detected in water samples in both channels. The golden alga had already appeared in two reservoirs near the Oder in May and April.
The Gleiwitz Canal, inaugurated in 1939, is 41 kilometers long and connects the Upper Silesian city of Gleiwitz (Gliwice) with the Oder. The 4.5 km long Kedzierzyn Canal branches off from the Gliwice Canal and leads to the nitrogen works in Kedzierzyn-Kozle.
As announced by the Ministry of the Environment, the crisis team recommends, among other things, temporarily sealing off the backwaters of the Oder and building natural barriers in retention basins to stop the development of golden algae.
In addition, the discharges of industrial and domestic waste water are to be systematically controlled depending on the water measurement values. Another recommendation of the crisis team is to enrich the water with oxygen.
Last summer there was a massive death of fish in the Oder. Experts in Germany and Poland concluded that the toxic effects of a bloom of the toxic golden alga Prymnesium parvum most likely caused the death of the fish.