Manipulation of fish community structure effectively restores submerged aquatic vegetation in a shallow subtropical lake

Chao Guo; Wei Li; Shiqi Li; Zhan Mai; Tanglin Zhang; Jiashou Liu; Adam G Hansen; Lin Li; Xingwei Cai; Brendan J Hicks

doi:10.1016/j.envpol.2021.118459

Manipulation of fish community structure effectively restores submerged aquatic vegetation in a shallow subtropical lake

Environ Pollut. 2022 Jan 1;292(Pt B):118459. doi: 10.1016/j.envpol.2021.118459. Epub 2021 Nov 2.

Authors

Chao Guo¹, Wei Li², Shiqi Li¹, Zhan Mai¹, Tanglin Zhang¹, Jiashou Liu¹, Adam G Hansen³, Lin Li⁴, Xingwei Cai⁵, Brendan J Hicks⁶

Affiliations

¹ State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
² State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; University of Chinese Academy of Sciences, Beijing, 100049, China. Electronic address: liwei@ihb.ac.cn.
³ Colorado Parks and Wildlife, Aquatic Research Section, Fort Collins, CO, USA.
⁴ State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
⁵ State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; Hainan Academy of Ocean and Fisheries Sciences, Haikou, 571126, China.
⁶ Centre for Biodiversity and Ecology Research, Department of Biological Sciences, Faculty of Science and Engineering, The University of Waikato, Hamilton, New Zealand.

PMID: 34740732
DOI: 10.1016/j.envpol.2021.118459

Abstract

Fish community manipulation and regulation has been largely overlooked as a mitigation strategy for restoring submerged aquatic vegetation (SAV) in shallow lakes of the middle and lower Yangtze River Basin (MLYRB). An in-situ fish exclusion experiment and a large-scale lake manipulation were conducted to test the hypothesis that the reasonable removal of benthivorous and herbivorous fish would facilitate the restoration and reconstruction of SAV in shallow lakes within the MLYRB. The in-situ exclusion experiment was conducted from April to October in 2017. Electrofishing was used to remove benthivorous and herbivorous fish from the exclosures. SAV were then artificially planted in the same pattern and density in both exclosures and adjacent open sites, and responses were measured for seven consecutive months. The mean percent coverage and biomass of SAV in the exclosures increased quickly and remained significantly higher than those in open sites over the duration of the experiment. Water quality also improved as turbidity, chlorophyll-a, total phosphorus and total nitrogen in the exclosures remained significantly lower than those in the open sites. After the in-situ experiment, a larger scale manipulation of fish in the entire submerged macrophyte zone (SMZ) was implemented from 2017 to 2020. After removing more than 2/3 of the benthivorous and herbivorous fish biomass by October 2020 in the SMZ, both the species richness and spatial coverage of SAV increased from 2 to 9 and from 1.7% to 32.2%, respectively. Our results provided clear evidence that fish are strong regulators of SAV productivity and that their reasonable removal facilitates ecological recovery. Therefore, we propose that fish community manipulation as implemented in this study be given more attention in addition to the reduction of external nutrient loading when designing projects to restore SAV in shallow lakes of the MLYRB.

Keywords: Benthivorous fish; Ecological restoration; Fish regulation; Herbivorous fish; Submerged aquatic vegetation.

MeSH terms

Animals
Chlorophyll A
Ecosystem*
Fishes
Lakes*
Phosphorus

Substances

Phosphorus
Chlorophyll A