Correlation of Fish Assemblages with Habitat and Environmental Variables in a Headwater Stream Section of Lijiang River, China

Jian Huang,Naicheng Wu,Qi Zou,Liangliang Huang,Zhiqiang Wu,Yuanmin Mo,Zhongbing Chen

doi:10.3390/su11041135

Abstract

In order to determine the relationship between stream habitat and fish assemblages, an investigation of fish assemblages and environmental variables in different habitat types was carried out in the headwater stream section of Lijiang River, China, from September to November 2016. In total, 2968 individuals belonging to 4 orders, 11 families, 26 genera and 37 species were collected. Cypriniformes emerged as the most species-rich order, accounting for 62.2% of the total species. The dominant species were Pseudogastromyzon fangi, Zacco platypus, Acrossocheilus parallens and Erromyzon sinensis. Non-metric multidimensional scaling (NMDS) and permutational multivariate analysis of variance (PERMANOVA) revealed that fish assemblages were not affected by habitat type. However, one-way ANOVA results showed that species richness, fish abundance, fish density and Shannon index were significantly affected by habitat type. Redundancy analysis (RDA) further revealed that altitude, velocity, conductivity, turbidity, depth and wetted width had significant relationships within fish assemblages, whereas water temperature, dissolved oxygen and substrate size were less important in this study, and different fish species preferred different environmental variables potentially due to differences in species’ ecological requirements. Although habitat type did not affect overall fish assemblages, habitat heterogeneity played an important role in fish diversity. Hence, maintaining diverse stream habitats or restoring them are of key importance for fish diversity conservation and sustainability management of rivers.

Highlights

In the broad sense, river habitat includes all the physical, chemical and biological characteristics in a river
The substrate size in step pool was significantly larger than other habitat types except the run (p < 0.05) (Table 2)
The fish in the study area account for 40.7% of the total species richness in Lijiang River, contribute to fish diversity [37], suggesting that headwater streams play an important role in fish diversity in river networks [25,33]

Summary

Introduction

River habitat includes all the physical, chemical and biological characteristics in a river. River habitat generally refers to the physical structure of rivers, including the river bed, bank and riparian zone, and it is a key component of stream ecosystems, playing a major role in determining biotic assemblages and stream integrity [1,2]. Fish are sensitive to changes in river habitats. They are good response indicators as they integrate the effects of multiple stressors [5]; they persist and recover from natural disturbances and may reflect both current and long-term environmental effects [6]. Habitat alterations that reduce complexity or decrease the stability of environmental conditions have been shown to reduce fish diversity and abundance [10,11]. Environmental variables such as current velocity, water depth, substrate size and pH have important effects on the growth and reproduction of the fish assemblages [13,14]

Methods

Results

Discussion

Conclusion