Stonewort (Chara contraria)
Phot. P. J. Szpygiel
Algae are the smallest
organisms, numbered among plant life, living in water. Algae can be
unicellular or multicellular organisms, they create filaments, colonies or
They are of various shapes and colours. They have a cytoblast and chloroplasts. They live in all places where there is water, even in vestigial quantities. They can be found in sand, snow
or on tree bark. They
are an important link in the matter cycle in nature. Many of them are food
for animals, e.g. some species of infusorians, turbellarian worms and
rotifers feed on algae.
Cryptomonas sp. - the most abundant species in the winter
and early spring phytoplankton of the Wigry Lake.
Phot. L. Wesołowska
During 100 years of irregular, often random research into algae in the area
of the Wigry National Park, over 600 taxa of these organisms have been found.
Phytoplankton (algae suspended in water) is researched best. The stoneworts
are the biggest algae and highest organized in structure. They grow in clean,
mesotrophic waters of the Park forming tufts or underwater meadows. They
belong to our biggest freshwater algae. Beautiful stonewort meadows are
found e.g. in lakes Dlugie and Biale. Mesotrophic basins with underwater
stonewort meadows – Charetea are under special habitat protection (Habitat
Directive of the UE).
Apart from stoneworts, Chlorophyceae can be seen most often with the unaided
eye. Some fish feed on Spirogyra filaments.