The city of Pskov is polluting Lake Peipsi
Thursday, March 18, 2004
The Estonian and Russian researchers’ first joint winter expedition to Lake
Peipsi, Lake Pskov and Lake Lämmijärv proved that the city of Pskov is the
worst polluter of Lake Peipsi.
After having crossed the three lakes in a hovercraft of the Border Guard
Administration and having taken many samples of water, biota and benthic
sediments, the researches of the two countries wanted to get a full picture
of the entire Lake Peipsi, the condition of which is largely affected by
Lake Pskov in the territory of Russia.
The studies carried out by the Estonian researchers in recent years show
that the condition of Lake Lämmijärv, Lake Pskov and the southern part of
Lake Peipsi has deteriorated abruptly and fast.
For example, the comparison of the samples taken in the summers of 2001 and
2003 revealed that the phosphate content near the estuary of the River
Velikaya had increased by 4 - 5 times over the two years.
According to Külli Kangur, a senior research fellow from the Institute of
Zoology and Botany, it is difficult to obtain reliable information from the
"There are a lot of parameters that they even don’t measure as, for
example,the content of chlorophyll, total phosphorus and total nitrogen in
water," said Kangur.
According to her, at the session of the joint commission of transboundary
water bodies, held in Pskov in October last year, the Russians provided an
accurate overview of the condition of our rivers, by using Estonian data,
however, did not provide any data concerning, for example, the River
"They either don’t have any data or they are reluctant to disclose this,"
The Velikaya River basin is more than twice as big as that of the River
Emajõgi and the city of Pskov, with a population more than twice that of
Tartu, lies on the banks of the Velikaya.
Estonian and Russian researches have not jointly explored the wintry Peipsi
before. The worst winter enemy of the lake - lack of oxygen - particularly
endangers the Russian side of the lake.
The algae, which develop in the upper water layers of the lake in summer,
settle on the bottom and consume oxygen while decaying. In winter, the lake
is covered with ice and the access of oxygen to the water is blocked. The
water of Lake Peipsi changes slowly and when oxygen disappears from the
water layers near the bottom, the phosphorus compounds bind with iron,
become disengaged, boosting the development of plankton in summer.
In the course of the joint expedition, the oxygen content of water was
measured on the bottom of Lake Pskov, 5-10 cm above the sludge boundary, and
the oxygen content was almost zero at all measuring points.
Kangur says that, nevertheless, the Russian researchers are not willing to
admit that the condition of the lake is getting worse. "They say that blooms
of algae proliferate and fish die only on the Estonian side and claim this
to happen due to natural reasons," said Kangur.
"We say that if the treatment facilities in Pskov worked properly and the
water level of Lake Peipsi rose, the condition of the lake would improve as
well. Unfortunately, only the first condition depends on people," she added.
Summarised from Vallo Nuust’s article in the Postimees newspaper of 17 March