Biomanipulating streams: a supplementary tool in lake restoration

TY - JOUR

T1 - Biomanipulating streams

T2 - a supplementary tool in lake restoration

AU - Skov, Christian

AU - Hansen, Joan H.

AU - Baktoft, Henrik

AU - Brodersen, Jakob

AU - Brönmark, Christer

AU - Hansson, Lars Anders

AU - Hulthén, Kaj

AU - Chapman, Ben B.

AU - Nilsson, P. Anders

PY - 2019/2

Y1 - 2019/2

N2 - Removal of cyprinid fish is a widely used biomanipulation tool to transform turbid shallow eutrophic lakes in north temperate regions into a clear water state. We here evaluate the removal of cyprinids from streams as a supplement to lake fishing. Since cyprinids often aggregate in high densities in lake inlet/outlet streams during winter migration, removal of fish in this space-confined habitat may be cost-efficient as compared to fish removal in the lake habitat. In two consecutive years, we annually removed up to 35% of the dominant cyprinids from an inlet stream to a lake and argue that this could easily be increased with a more targeted fishing effort. Concurrently, we monitored species- and length-specific variation in migration propensity, to explore how this relates to efficient fish removal. Smaller planktivores generally had a much higher migratory propensity than larger benthivores. Hence, stream fishing specifically targets species and size groups that are less efficiently controlled with traditional lake fishing methods. As a rule of thumb, stream fishing is most efficient when water temperature is 2–6°C. Prior to implementing fish removals from streams, the potential evolutionary consequences of the targeted removal of migratory phenotypes should be considered.

AB - Removal of cyprinid fish is a widely used biomanipulation tool to transform turbid shallow eutrophic lakes in north temperate regions into a clear water state. We here evaluate the removal of cyprinids from streams as a supplement to lake fishing. Since cyprinids often aggregate in high densities in lake inlet/outlet streams during winter migration, removal of fish in this space-confined habitat may be cost-efficient as compared to fish removal in the lake habitat. In two consecutive years, we annually removed up to 35% of the dominant cyprinids from an inlet stream to a lake and argue that this could easily be increased with a more targeted fishing effort. Concurrently, we monitored species- and length-specific variation in migration propensity, to explore how this relates to efficient fish removal. Smaller planktivores generally had a much higher migratory propensity than larger benthivores. Hence, stream fishing specifically targets species and size groups that are less efficiently controlled with traditional lake fishing methods. As a rule of thumb, stream fishing is most efficient when water temperature is 2–6°C. Prior to implementing fish removals from streams, the potential evolutionary consequences of the targeted removal of migratory phenotypes should be considered.

KW - Cost-effective

KW - Cyprinid fishes

KW - Evolutionary consequences

KW - Fish removal

KW - Migration

U2 - 10.1007/s10750-018-3832-4

DO - 10.1007/s10750-018-3832-4

M3 - Article

AN - SCOPUS:85057100636

VL - 829

SP - 205

EP - 216

JO - Hydrobiologia

JF - Hydrobiologia

SN - 0018-8158

IS - 1

ER -