Geoscience Reference
In-Depth Information
Although fished only seasonally when it enters the lagoon for spawning, herring
constitutes the most important catch in terms of biomass (1000 to 4000 t per year
in the Polish part of the lagoon and about 8000 t per year in the Russian part). 11
Freshwater and migratory species are of great economic value. Pikeperch, bream,
roach, and perch are the main freshwater species. Eel and sea trout are the main
migrating species. The existence of some valuable species such as eel or pike is
threatened by overfishing and the destruction of fishing grounds. Some species need
regular restocking. 11
9.4.1.2
Anthropogenic Pressure and Its Environmental Effects
According to the HELCOM Baltic Sea Joint Comprehensive Action Programme 6,7
(HELCOM 1992 and 1998), numerous “hot spots” are located near the Vistula
Lagoon. The lagoon itself has been identified as a priority hot spot, which is in need
of a comprehensive environmental management program. Environmental improve-
ment investment is estimated to be 20 million EURO. The Kaliningrad area has been
defined by HELCOM as one of the seven “multiple problem areas” in the Baltic
Sea catchment area. These hot spots are by definition the most significant contrib-
utors to the pollution of the Baltic Sea. They include both point and nonpoint sources,
as well as the above-mentioned hot spot of the lagoon itself. 12
Based on available knowledge, 7,12 the most important environmental problems
of the Vistula Lagoon are:
• Poor sanitary conditions in the southern part of the lagoon make the water
quality so bad that no beaches along the southern lagoon shores are
suitable for swimming, and this basin is not attractive for water sports.
• Eutrophication adversely affects the aesthetics of the water and may have
negative biological effects.
• Treatment facilities in Kaliningrad and other coastal towns are poor, and
there is direct run-off of a portion of untreated wastewater into the Pregel
River and the Primorskaya Bight (the northern part of the Vistula Lagoon).
• Autumn wind-surge events in the lower Pregel River result in the move-
ment of polluted water from the Kaliningrad harbor toward the drinking
water inlets located upstream from Kaliningrad or the direct blocking of
these inlets by saline lagoon water. 13
• There is oxygen deficiency in the lower Pregel during warm summer
periods. 14
• The intensification of water exchange with the Baltic Sea due to continual
dredging in the Baltijsk Strait because of shipping development leads to
further increases in salinity of lagoon waters. 15,16
• Use of portions of the Polish part of the Vistula Spit for recreational
purposes during the summer season exceeds the carrying capacity of the
resources (e.g., the Krynica Morska recreational area).
• Pressure on fishing resources is aggravated by legal and illegal fishing
activities.
 
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