Vesijärvi is a lake of near Lahti in southern Finland. It suffered severe effects of eutrophication in the 1960s and a restoration programme began in the 1970s. The

Enonselkä Basin Enonselkä Basin is a lake basin of Lake Vesijärvi in Lahti Lahti (; sv, Lahtis) is a city and municipality in Finland. It is the capital of the region of Päijänne Tavastia (Päijät-Häme) and its growing region is one of the main econ ...

is a part of Vesijärvi. The name of the lake means ''The Water Lake''.

Cyanobacteria Bloom Remediation

Biomanipulation Biomanipulation is the deliberate alteration of an ecosystem by adding or removing species, especially predators. Aquatic ecosystems Changing the fish population of bodies of water as a part of watershed management can facilitate desirable changes ...

is an approach that applies the top-down model of community organization to alter ecosystem characteristics. * Ecologists used

cyanobacteria Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blu ...

blooms as an alternative to using chemical treatments. * Lake Vesijärvi was polluted by city sewage and industrial wastewater until 1976, at which point pollution controls reduced these inputs. By 1986 massive blooms of cyanobacteria began occurring, as well as dense populations of

roach Roach may refer to: Animals * Cockroach, various insect species of the order Blattodea * Common roach (''Rutilus rutilus''), a fresh and brackish water fish of the family Cyprinidae ** ''Rutilus'' or roaches, a genus of fishes * California roach ...

, a fish that benefited from the pollution's mineral nutrients. Roach eat zooplankton that otherwise keep cyanobacteria in check. To remediate this problem, ecologists removed about a million of kilograms of fish, reducing roach to 20% of their former abundance, between 1989 and 1994, and stocked the lake with

pike perch ''Sander'' (formerly known as ''Stizostedion'') is a genus of predatory ray-finned fish in the family Percidae, which also includes the perches, ruffes, and darters. They are also known as "pike-perch" because of their resemblance to fish in th ...

which eats roach. The water has since become clear, and the last cyanobacteria bloom was in 1989.

In popular culture

* The ninth track on Geographer's 2012 album ''Myth'' is titled "Vesijärvi".

References

External links

Kymi basin Lakes of Lahti {{SouthernFinland-geo-stub

Cyanobacteria Bloom Remediation

In popular culture

See also

References

External links