Food-web construction and ecological effects of implementing non-traditional biomanipulation in eutrophic reservoirs in North-central China

ABSTRACT

This study was undertaken to elucidate the food web structure and interspecific interactions in the lakes and reservoirs undergoing eutrophication and to assess the efficacy of lake-wide non-traditional biomanipulation (direct predation of cyanobacteria by proliferating planktivorous fish) for bloom management. Analyses of aquatic organisms and stable isotopes of basic food sources and consumers were performed for Zhangze Reservoir in North-central China. Additionally, an improved scheme based on plankton changes and interspecific interactions is proposed on this basis. Compared with other widely-studied eutrophic reservoirs, the δ¹⁵N value of each component of the food web in Zhangze Reservoir was higher, the food chain was relatively long and the δ¹³C range of fish consumers was narrower. Planktivorous fish consumed phytoplankton as their primary food source. However, the phytoplankton biomass and the percentage of cyanobacteria increased, and eutrophication did not improve. The findings concerning the composition of consumers and their food sources in Zhangze Reservoir indicate the urgent need to change the fish structure to optimise the structure of plankton community and mitigate phytoplankton overgrowth. The study findings provide a basis for the implementation of effective eutrophication management strategies in lakes and reservoirs where planktivorous fish are prevalent.

KEYWORDS:

• Eutrophication
• biomanipulation
• stable isotope
• food web
• Zhangze Reservoir

Acknowledgements

This project was supported by the National Natural Science Foundation of China (grant number 51679191) and Shaanxi Provincial Natural Science Basic Research Program (2019JLM-60). We are very grateful to Shanxi Zhangze Reservoir Management Co., Ltd. for allowing us to enter the field sites and for their assistance in the field work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Additional information

Funding

This work was supported by National Natural Science Foundation of China: [Grant Number 51679191]; Shaanxi Provincial Natural Science Basic Research Program: [Grant Number 2019JLM-60].

Notes on contributors

Ruijing Yang

Ruijing Yang is a 4th year PhD Student in Environmental Engineering.

Minquan Feng

Minquan Feng is a professor and specialist in Water Environment Management and Ecological Restoration.

Zimeng Liu

Zimeng Liu is a 3th year Master's Student in Environmental Engineering.

Guoguo Liu

Guoguo Liu is a 2th year Master's Student in Environmental Engineering.