3.9 Related Rates/3
Template:Short description Template:Expand Polish Template:Expand German Template:Use dmy dates Template:Infobox event During the summer of 2022, a mass mortality event involving fish, beavers and other wildlife occurred in the Oder river, which flows through Poland to Germany, partly forming the German–Polish border, and then drains into the Baltic Sea. Over Template:Convert<ref name=guardian/> of dead fish were removed, causing concern that the water was poisoned.
While the cause is not yet clear, theories include the effects of the summer heat and lower water levels due to the European drought, reduced oxygen levels due to the heat and nutrient loading, a spike in oxygen levels due to the introduction of an oxidizing agent, and pollution by chemicals including mercury, mesitylene, salts or other sewage.
The Polish authorities were slow to react and this became a scandal, resulting in the dismissal of officials responsible for water management and environmental protection. A reward of a million złoty (US$210,000 as of August 2022) was offered for information about possible culprits.<ref>Template:Cite news</ref>
Discovery[edit]
Fish deaths were reported by anglers around Oława as early as March of 2022. Large kills then started again at the end of July.<ref name=DW>Template:Citation</ref> On 11 August 2022, volunteers and anglers removed at least 10 tonnes of dead fish from the Template:Cvt stretch of the river north of Oława in southwest Poland.<ref name=":0">Template:Cite news</ref><ref>Template:Cite web</ref><ref name=sky>Template:Cite web</ref><ref>Template:Cite web</ref> The discovery was made by local fishermen, as opposed to any regulatory or testing body.<ref>Template:Cite web</ref> Other dead animals included beavers and birds.<ref>Template:Cite news</ref>
Cause[edit]
Early on, it was suspected that the cause of the die-off was poisoning by an unknown toxic substance.<ref>Template:Cite news</ref> Water samples taken on 28 July showed a high probability of the presence of the contaminant mesitylene, although the Polish government claimed that it was not present on samples taken after 1 August.<ref name=":0" /><ref>Template:Cite web</ref>
A German testing lab had found traces of mercury,<ref>Template:Cite web Template:Webarchive</ref> but the Polish government reported that their tests determined that mercury poisoning was not the cause of the die-off.<ref>Template:Cite web</ref>
According to the Brandenburg Environment Minister, Axel Vogel, German laboratories believe the fish deaths may have been the result of a large amount of salt in the water.<ref>Template:Cite web</ref> Data gained via an automatic water quality measuring station in Frankfurt an der Oder (over Template:Cvt downstream) indicated that from 4 August the electrical conductivity had climbed anomalously. This data also showed a large change in other water quality parameters. On 7 August, dissolved oxygen, electrical conductivity and UV absorption almost doubled; nitrate levels plummeted and chlorophyl increased by a factor of ten. The water also became more turbid and its pH increased to about 8.8–9.2. This could be indicative of increased levels of salt in the river<ref>Template:Cite web</ref>, consistent with the conclusion that since 7 August a huge amount of salt reached the town.<ref>Template:Cite web</ref>
Implications[edit]
The ecosystem of the river was severely damaged. Scientists are concerned that if the damage was caused by mercury poisoning, it will last a long time, as mercury is a persistent heavy metal.<ref>Template:Cite web</ref> There are also potential serious health consequences for humans.<ref>Template:Cite web</ref>
Reaction[edit]
The Prime Minister of Poland Mateusz Morawiecki was put under pressure to act and fired two government officials as a result (the head of the water authority, Template:Ill, Template:Ill, and the head of the environmental authority, Template:Ill, Template:Ill).<ref>Template:Cite web</ref><ref>Template:Cite web</ref> This in turn caused internal rifts in the ruling Law and Justice party.<ref name="gazeta1">Template:Cite web</ref>
Local residents reacted negatively to the government's actions,<ref>Template:Cite web</ref> and, with the state television avoiding reporting on the subject, widespread allegations of a government cover-up began.<ref>Template:Cite web</ref><ref name="wiadWP">Template:Cite web</ref> Criticism also fell on the local voivodes.<ref name="gazeta1"/>
The Polish opposition blamed the Polish government for reacting slowly to the developing situation, and downplaying the scale of the problem.<ref>Template:Cite web</ref> The government said the perpetrators would be severely punished, while blaming opposition politicians, in particular Donald Tusk and Rafał Trzaskowski, for exaggerating the issue. The government media comparing the situation to other previous minor and unrelated events in Warsaw and Gdańsk, where the opposition Civic Platform holds power.<ref name="wiadWP"/> On August 12, the deputy minister of infrastructure, Template:Ill, blamed the opposition and the ecologists, and stated that the river was safe to enter, and fishing is allowed.<ref>Template:Cite web</ref> Krystyna Pawłowicz, a Eurosceptic member of the Law and Justice party, has publicly announced a disproven theory that the cause of the disaster was due to foreign actors.<ref>Template:Cite web</ref>
Some anglers fear that fish might never return to the river,<ref>Template:Cite web</ref> and Steffi Lemke, the German Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection, called the situation a catastrophe and a shocking ecological disaster.<ref>Template:Cite web</ref> German officials have also complained about the lack of communication from the Polish officials.<ref name=guardian>Template:Cite web</ref>