TY - JOUR

T1 - Fish manipulation as a lake restoration tool in shallow, eutrophic temperate lakes 1

T2 - cross-analysis of three Danish case-studies

AU - Jeppesen, E.

AU - Søndergaard, M.

AU - Mortensen, E.

AU - Kristensen, P.

AU - Riemann, B.

AU - Jensen, H. J.

AU - Müller, J. P.

AU - Sortkjær, O.

AU - Jensen, J. P.

AU - Christoffersen, K.

AU - Bosselmann, S.

AU - Dall, E.

PY - 1990/8

Y1 - 1990/8

N2 - The use of fish manipulation as a tool for lake restoration in eutrophic lakes has been investigated since 1986 in three shallow, eutrophic Danish lakes. The lakes differ with respect to nutrient loading and nutrient levels (130-1000 μg P l-1, 1-6 mg N l-1). A 50% removal of planktivorous fish in the less eutrophic cyanobacteria-diatom dominated Lake Væng caused marked changes in lower trophic levels, phosphorus concentration and transparency. Only minor changes occurred after a 78% removal of planktivorous fish in eutrophic cyanobacteria dominated Frederiksborg Castle Lake. In the hypertrophic, green algae dominated Lake Søbygård a low recruitment of all fish species and a 16% removal of fish biomass created substantial changes in trophic structure, but no decrease in phosphorus concentration. The different response pattern is interpreted as (1) a difference in density and persistence of bloomforming cyanobacteria caused by between-lake variations in nutrient levels and probably also mixing- and flushing rates, (2) a difference in specific loss rates through sedimentation of the algal community prevaling after the fish manipulation, (3) a decreased impact of planktivorous fish with increasing mean depth and (4) a lake specific difference in ability to create a self-increasing reduction in the phosphorus level in the lake water. This in turn seems related to the phosphorus loading.

AB - The use of fish manipulation as a tool for lake restoration in eutrophic lakes has been investigated since 1986 in three shallow, eutrophic Danish lakes. The lakes differ with respect to nutrient loading and nutrient levels (130-1000 μg P l-1, 1-6 mg N l-1). A 50% removal of planktivorous fish in the less eutrophic cyanobacteria-diatom dominated Lake Væng caused marked changes in lower trophic levels, phosphorus concentration and transparency. Only minor changes occurred after a 78% removal of planktivorous fish in eutrophic cyanobacteria dominated Frederiksborg Castle Lake. In the hypertrophic, green algae dominated Lake Søbygård a low recruitment of all fish species and a 16% removal of fish biomass created substantial changes in trophic structure, but no decrease in phosphorus concentration. The different response pattern is interpreted as (1) a difference in density and persistence of bloomforming cyanobacteria caused by between-lake variations in nutrient levels and probably also mixing- and flushing rates, (2) a difference in specific loss rates through sedimentation of the algal community prevaling after the fish manipulation, (3) a decreased impact of planktivorous fish with increasing mean depth and (4) a lake specific difference in ability to create a self-increasing reduction in the phosphorus level in the lake water. This in turn seems related to the phosphorus loading.

KW - biomanipulation

KW - cross-analysis

KW - eutrophic

KW - lake restoration

KW - lakes

KW - shallow

KW - trophic cascade

UR - http://www.scopus.com/inward/record.url?scp=0025603913&partnerID=8YFLogxK

U2 - 10.1007/BF02530340

DO - 10.1007/BF02530340

M3 - Journal article

AN - SCOPUS:0025603913

VL - 200-201

SP - 205

EP - 218

JO - Journal of Aquatic Ecosystem Health

JF - Journal of Aquatic Ecosystem Health

SN - 0018-8158

IS - 1

ER -