<abstract xmlns="http://www.w3.org/1999/xhtml">Since 1967, the temperate, shallow, pond-type Lake Warniak has been subjected to different biomanipulation methods including the introduction of common carp, <italic>Cyprinus carpio</italic> L., grass carp, <italic>Ctenopharyngodon idella</italic> (Val.), silver carp, <italic>Hypophthalmichthys molitrix</italic> (Val.), and bighead carp, <italic>Hypophthalmichthys nobilis</italic> (Richardson) and then their removal in an effort to control macrophytes and phytoplankton. Recently, pilot stocking with predatory fish, particularly pike, <italic>Esox lucius</italic> L., has also been conducted. Hence, an examination of the long-term response patterns of phytoplankton to multiple fish-induced stressors was undertaken. In recent years, <italic>Chara</italic> domination (2000-2004) has helped to stabilize a clear-water state, high/good ecological status, and meso-eutrophic conditions. After the disappearance of Charales in 2004, the rapid, unstable changes in phytoplankton biomass, structure, and biodiversity suggested a shift toward a turbid-water state. As a result, the phytoplankton assemblages changed from those dominated by cryptophytes Y+X2+X1+LO (2000-2004) through those dominated by cyanobacteria K (2005-2008), dinoflagellates LO+Y (2009-2011), and cryptophytes Y+LO+F+X2 (2012), to those dominated by diatoms D+K+P+A (2013-2014) with representative taxa that occur in nutrient-rich and/or nutrient-poor water bodies. The 1967-2014 changes indicated that four periods, two with clear-water state and two with turbid-water state, alternately, one after the other, resulted from different fish pressure. Higher autochthonous fish biomass was usually accompanied by lower phytoplankton biomass. In contrast, the introduction of Cyprinidae fish had a stimulating effect on summer phytoplankton dominated by cyanobateria. Among the nutrients, only phosphorus played an important role.</abstract>

Since 1967, the temperate, shallow, pond-type Lake Warniak has been subjected to different biomanipulation methods including the introduction of common carp, Cyprinus carpio L., grass carp, Ctenopharyngodon idella (Val.), silver carp, Hypophthalmichthys molitrix (Val.), and bighead carp, Hypophthalmichthys nobilis (Richardson) and then their removal in an effort to control macrophytes and phytoplankton. Recently, pilot stocking with predatory fish, particularly pike, Esox lucius L., has also been conducted. Hence, an examination of the long-term response patterns of phytoplankton to multiple fish-induced stressors was undertaken. In recent years, Chara domination (2000-2004) has helped to stabilize a clear-water state, high/good ecological status, and meso-eutrophic conditions. After the disappearance of Charales in 2004, the rapid, unstable changes in phytoplankton biomass, structure, and biodiversity suggested a shift toward a turbid-water state. As a result, the phytoplankton assemblages changed from those dominated by cryptophytes Y+X2+X1+LO (2000-2004) through those dominated by cyanobacteria K (2005-2008), dinoflagellates LO+Y (2009-2011), and cryptophytes Y+LO+F+X2 (2012), to those dominated by diatoms D+K+P+A (2013-2014) with representative taxa that occur in nutrient-rich and/or nutrient-poor water bodies. The 1967-2014 changes indicated that four periods, two with clear-water state and two with turbid-water state, alternately, one after the other, resulted from different fish pressure. Higher autochthonous fish biomass was usually accompanied by lower phytoplankton biomass. In contrast, the introduction of Cyprinidae fish had a stimulating effect on summer phytoplankton dominated by cyanobateria. Among the nutrients, only phosphorus played an important role.

Phytoplankton response to fish-induced environmental changes in a temperate shallow pond-type lake

Department of Ichthyology, Hydrobiology and Aquactic Ecology, Inland Fisheries Institute in Olsztyn

Fisheries & Aquatic Life

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Since 1967, the temperate, shallow, pond-type Lake Warniak has been subjected to different biomanipulation methods including the introduction of common carp,...

Phytoplankton response to fish-induced environmental changes in a temperate shallow pond-type lake

Published Online: Jan 24, 2018

Page range: 211 - 262

Received: Aug 24, 2017

Accepted: Nov 26, 2017

DOI: https://doi.org/10.1515/aopf-2017-0020

Keywords
alternative stable states, domination shifts, biomass, cyanobacteria, autochthonous fish, introduced fish

© 2017 Archives of Polish Fisheries

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Phytoplankton response to fish-induced environmental changes in a temperate shallow pond-type lake

Published Online: Jan 24, 2018

Page range: 211 - 262

Received: Aug 24, 2017

Accepted: Nov 26, 2017

DOI: https://doi.org/10.1515/aopf-2017-0020

Keywordsalternative stable states, domination shifts, biomass, cyanobacteria, autochthonous fish, introduced fish

© 2017 Archives of Polish Fisheries

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
alternative stable states, domination shifts, biomass, cyanobacteria, autochthonous fish, introduced fish