Last Updated:

10/09/2020 - 13:04

The research article “A small omnivorous bitterling fish (Acheilognathus macropterus) facilitates dominance of cyanobacteria, rotifers and Limnodrilus in an outdoor mesocosm experiment”, co-authored by METU visiting researcher Prof. Erik Jeppesen, has been published in Environmental Science and Pollution Research.

Small omnivorous fish often dominate in subtropical shallow lakes, and they may affect the community structure of aquatic organisms on at least two trophic levels. However, in the study of aquatic food webs in subtropical lakes, most ecologists have focused on the effects of large-sized omnivorous species (e.g. common carp), studies of small-sized species being scarce. We conducted a mesocosm experiment with two treatments (fish presence and absence) to examine the effects of a small-sized omnivore, bitterling (Acheilognathus macropterus), on phytoplankton, zooplankton and benthic macroinvertebrates. Our results showed that bitterling presence significantly increased the chlorophyll a concentration and biomass of phytoplankton, which became dominated by cyanobacteria (mainly Aphanizomenon spp.) that accounted for >99% of both total phytoplankton abundance and biomass. Both the abundance and biomass of zooplankton were also higher in the fish-present treatment, but small rotifers became dominant, and the zooplankton:phytoplankton biomass ratio decreased, indicating less grazing on phytoplankton. Moreover, both the abundance and biomass of benthic macroinvertebrates (tubificids) were higher in the bitterling-present treatment than in the controls, which is opposite to the situation found when omni-benthivorous fish (e.g. crucian carp) dominate. Higher biomass of tubificids may, in turn, result in higher sediment nutrient release. Our study suggests that A. macropterus, and maybe also other bitterling species, can alter both pelagic and benthic assemblages via both top-down and bottom-up control effects and lead to more turbid water in eutrophic lakes. Thus, more attention should be paid to these small omnivorous species in the restoration and management of shallow subtropical lakes.

Yu, J., Xia, M., Kong, M., He, H., Guan, B., Liu, Z., & Jeppesen, E. (2020). A small omnivorous bitterling fish (acheilognathus macropterus) facilitates dominance of cyanobacteria, rotifers and limnodrilus in an outdoor mesocosm experiment. Environmental Science and Pollution Research, 27(19), 23862-23870. doi:10.1007/s11356-020-08774-5


Article access:

METU Author

Prof. Erik Jeppesen

Web of Science/Publons Researcher ID: A-4463-2012
Scopus Author ID: 7005087752
ORCID: 0000-0002-0542-369X


Benthic macroinvertebrates; Lake restoration; Omnivore; Phytoplankton; Zooplankton

Other authors:
Yu J., Xia M., Kong M., He H., Guan B., & Liu Z.

Our study was supported by the National Natural Science Foundation of China (41877415), Major Science and Technology Program for Water Pollution Control and Treatment (2017ZX07203-004) and the NIGLAS 135 Project (NIGLAS2018GH04). JL was supported by the Chinese Academy of Sciences (CAS) Scholarship for a 1-year research visit at the Flathead Lake Biological Station, University of Montana, USA. EJ was supported by AQUACOSM (Network of Leading European AQUAtic MesoCOSM Facilities Connecting Mountains to Oceans from the Arctic to the Mediterranean), AnaEE Denmark (, the Centre for Water Technology at Aarhus University ( ) and the Tübitak outstanding researcher program BIDEB 2232.