Effects of Artificial Reefs on Phytoplankton Community Structure in Baiyangdian Lake, China

Hao Zhu,Shuiping Cheng,Jie Wang,Xingguo Liu

doi:10.3390/w13131802

Abstract

The habitat and feeding environment of freshwater fish in freshwater lakes have been destroyed, with the problem of miniaturization and simplification of catches being serious. An artificial reef is an effective technical measure to protect and proliferate offshore fishery resources, but little research has been conducted on its application in freshwater lakes. A small artificial reef for freshwater lakes was designed according to the water depth of the lake and the habits of benthic fish. The artificial reef is composed of biomass modules, each of which is 900 × 120 mm. The community structure of phytoplankton around the artificial reef and its adjacent waters was studied. The results showed that 77 species from seven phyla were identified, with a high number of species from the Chlorophyceae. In terms of density composition, the density of cyanobacteria decreased month by month, while the phylum Chlorophyta and Cryptophyta increased first and then decreased. As for biomass composition, Chlorophyta and Cryptophyta increased first and then decreased. RDA analysis showed that water temperature, dissolved oxygen, and total phosphorus were the main influencing factors. To sum up, the artificial reef can improve the algae phase in the surrounding water column, inhibit the growth and reproduction of cyanobacteria to a certain extent, and have a significant enrichment and promotion effect on diatoms. Artificial fish reef affects the phytoplankton community structure of the surrounding water bodies mainly through the absorption of phosphorus nutrients. Artificial reefs can be popularized and applied in freshwater lakes to provide foraging and shelter for benthic fish in the lake.

Highlights

Baiyangdian Lake is located in the planning area of Xiong’an New District (XND)in Hebei Province, China
It is situated in the middle of the North China Plain and the middle reaches of the Daqing River in the Haihe River Basin, as the largest freshwater lake in North China [1]
From July 2019 to November 2019, this study was conducted in Shihoudian Lake in the Baiyangdian Lake Basin, located in XND, Baoding City, Hebei Province (38◦ 500 39.3900 N, 115◦ 590 30.0400 E, Figure 1)

Summary

Introduction

It is situated in the middle of the North China Plain and the middle reaches of the Daqing River in the Haihe River Basin, as the largest freshwater lake in North China [1]. It has ecological functions such as regional water resource storage and regulation, water purification, local climate regulation, flood prevention and mitigation, and conservation of species diversity; it is known as the “Kidney of North China” [2,3]. The Baiyangdian Lake Basin has experienced an arid climate and frequent drying periods [4]. Fishery in Baiyangdian Lake faces declines catches and low species diversity, with catches often being small and juvenile fish of undesirable species and migratory fishes have largely

Methods

Results

Discussion

Conclusion