46
R. Cie´ sli´ nski
strongly eutrophic, and the trophic state of the park’s lakes depends on the quality of
river water, which is rated less than good. Hence, the main threats to water quality in
the park are river water quality and any changes in the hydrographic network [30].
Poleski National Park features four ł˛ eczy´ nsko-włodawskie lakes District and
numerous ponds. An additional eight lakes are found in the near-park zone, with one
lake transformed into a retention reservoir. Three of the four lakes found in the park
are dystrophic lakes, while one is a eutrophic lake [32]. All the lakes are shallow
and their surface area ranges from 3.52 ha to 131.63 ha. Fluctuations in water levels
slightly exceed 40 cm [33]. Water usage in the park is low and includes mostly local
water collection for economic purposes. A limited amount of commercial fishing
is allowed on several ponds. Amateur fishing is allowed on one pond. Lakes in the
park are not available for recreational purposes and only serve research and teaching
purposes. Commercial fishing is limited to selection and control catches [33]. The
water balance in the park today is the product of human impact leading to lowered
water levels [34]. One of the main problems in the park is unregulated wastewater
management in the form of wastewater releases into some lakes as well as the use of
fertilizer and pesticides in local agriculture [33]. Other problems include drainage
ditches dug in the 1950s and two subsequent decades as well as corresponding
changes in the land use structure [35].
Roztocza ´
nski National Park is characterized by the presence of numerous ponds.
Ko´ scielny Pond is one of the more interesting of the ponds with a historic water mill
at its outlet and also a baroque church on an island. Other interesting ponds include
Echo, Czarny Staw, and Staw Florianiecki. The park also includes Rudka recreation
pond whose water temperature in summer is only 15 °C, which limits its usefulness
as a swimming hole. A retention reservoir is used by a paper mill in Zwierzyniec.
Water usage in the park is limited to household use by park ranger stations and surface
water use by the Echo, Czarny, and Florianiecki ponds. In the summer, the park is
visited by large numbers of tourists driving cars [36]. The main threat to surface water
quality in the park is the influx of agricultural and household-type pollutants along
with low emissions polluting the local air. Other threats include a decreasing supply
of groundwater, drainage works performed in the park in the 1960s and 1970s, and
an increase in overall human impact [37].
Słowi ´
nski National Park is unique among national parks in Poland in that it is
characterized by the highest share of water areas at more than 60% [38]. This is
the largest water-based national park in Poland due to the presence of two large
lakes—Lake Łebsko and Lake Gardno—and additionally three smaller lakes—
Dołgie Wielkie, Dołgie Małe, Smołdzi´ nskiego. The two larger lakes were formed
as a result of sand migration from the Łeba sandbar, eventually covering parts of a
lagoon in the northeastern corner of present-day Lake Gardno. The lagoon existed
until the seventeenth century. The third lake became separated from Lake Gardno in
the mid-twentieth century due to the land formation [39]. The park’s hydrographic
network was subject to strong human impact beginning in the mid-eighteenth century
when a local water balance program was set into motion in the Pomerania region
(Fig. 3.5).
R. Cie´ sli´ nski
strongly eutrophic, and the trophic state of the park’s lakes depends on the quality of
river water, which is rated less than good. Hence, the main threats to water quality in
the park are river water quality and any changes in the hydrographic network [30].
Poleski National Park features four ł˛ eczy´ nsko-włodawskie lakes District and
numerous ponds. An additional eight lakes are found in the near-park zone, with one
lake transformed into a retention reservoir. Three of the four lakes found in the park
are dystrophic lakes, while one is a eutrophic lake [32]. All the lakes are shallow
and their surface area ranges from 3.52 ha to 131.63 ha. Fluctuations in water levels
slightly exceed 40 cm [33]. Water usage in the park is low and includes mostly local
water collection for economic purposes. A limited amount of commercial fishing
is allowed on several ponds. Amateur fishing is allowed on one pond. Lakes in the
park are not available for recreational purposes and only serve research and teaching
purposes. Commercial fishing is limited to selection and control catches [33]. The
water balance in the park today is the product of human impact leading to lowered
water levels [34]. One of the main problems in the park is unregulated wastewater
management in the form of wastewater releases into some lakes as well as the use of
fertilizer and pesticides in local agriculture [33]. Other problems include drainage
ditches dug in the 1950s and two subsequent decades as well as corresponding
changes in the land use structure [35].
Roztocza ´
nski National Park is characterized by the presence of numerous ponds.
Ko´ scielny Pond is one of the more interesting of the ponds with a historic water mill
at its outlet and also a baroque church on an island. Other interesting ponds include
Echo, Czarny Staw, and Staw Florianiecki. The park also includes Rudka recreation
pond whose water temperature in summer is only 15 °C, which limits its usefulness
as a swimming hole. A retention reservoir is used by a paper mill in Zwierzyniec.
Water usage in the park is limited to household use by park ranger stations and surface
water use by the Echo, Czarny, and Florianiecki ponds. In the summer, the park is
visited by large numbers of tourists driving cars [36]. The main threat to surface water
quality in the park is the influx of agricultural and household-type pollutants along
with low emissions polluting the local air. Other threats include a decreasing supply
of groundwater, drainage works performed in the park in the 1960s and 1970s, and
an increase in overall human impact [37].
Słowi ´
nski National Park is unique among national parks in Poland in that it is
characterized by the highest share of water areas at more than 60% [38]. This is
the largest water-based national park in Poland due to the presence of two large
lakes—Lake Łebsko and Lake Gardno—and additionally three smaller lakes—
Dołgie Wielkie, Dołgie Małe, Smołdzi´ nskiego. The two larger lakes were formed
as a result of sand migration from the Łeba sandbar, eventually covering parts of a
lagoon in the northeastern corner of present-day Lake Gardno. The lagoon existed
until the seventeenth century. The third lake became separated from Lake Gardno in
the mid-twentieth century due to the land formation [39]. The park’s hydrographic
network was subject to strong human impact beginning in the mid-eighteenth century
when a local water balance program was set into motion in the Pomerania region
(Fig. 3.5).