Biomanipulating streams : a supplementary tool in lake restoration

Skov, Christian; Hansen, Joan H.; Baktoft, Henrik; Brodersen, Jakob, et al. (2019-02). Biomanipulating streams : a supplementary tool in lake restoration. Hydrobiologia, 829, (1), 205 - 216
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DOI:
| Published | English
Authors:
Skov, Christian ; Hansen, Joan H. ; Baktoft, Henrik ; Brodersen, Jakob , et al.
Department:
Division aquatic ecology
Aquatic Ecology
Research Group:
Aquatic Ecology
Abstract:

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.

Keywords:
Cost-effective ; Cyprinid fishes ; Evolutionary consequences ; Fish removal ; Migration
ISSN:
0018-8158
LUP-ID:
b4675e6d-d514-4b6a-a083-ae476ee9ed12 | Link: https://lup.lub.lu.se/record/b4675e6d-d514-4b6a-a083-ae476ee9ed12 | Statistics

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