Vesijärvi is a

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

of near

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 economic hubs of Finland. Lahti is situated on a bay at the southern e ...

in southern Finland. It suffered severe effects of

eutrophication Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phyt ...

in the 1960s and a restoration programme began in the 1970s. The Enonselkä Basin is a part of Vesijärvi. The name of the lake means ''The Water Lake''.

Cyanobacteria Bloom Remediation

* Biomanipulation 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, bl ...

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 roa ...

, a fish that benefited from the pollution's mineral nutrients. Roach eat

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

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 the ...

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 A geographer is a physical scientist, social scientist or humanist whose area of study is geography, the study of Earth's natural environment and human society, including how society and nature interacts. The Greek prefix "geo" means "earth" a ...

'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