Autumn ichthyoplankton assemblage in the Yangtze Estuary shaped by environmental factors.

Hui Zhang,Weiwei Xian,Shude Liu

doi:10.7717/peerj.1922

Abstract

This study investigated the response of the ichthyoplankton community to environmental changes in the Yangtze Estuary using canonical correspondence analysis. Ichthyoplankton community and environmental data were recorded during the autumns of 1998, 2000, 2002, 2003, 2004, 2007 and 2009. Among the ichthyoplankton, the dominant larval and juvenile families were the Engraulidae, Gobiidae and Salangidae, and the most common eggs were from Trichiurus lepturus. The ichthyoplankton was identified via canonical correspondence analysis to three assemblages: an estuary assemblage dominated by Chaeturichthys stigmatias, a coastal assemblage dominated by Engraulis japonicus and Stolephorus commersonii, and an offshore assemblage dominated by Trichiurus lepturus. Regarding environmental factors in the Yangtze Estuary, suspended matter and surface seawater salinity were the main factors influencing the distributions of the different assemblages, while sediment from the Yangtze River during the rainy season and chlorophyll a were the principle drivers of the annual variances in the distribution of ichthyoplankton assemblages. Our aims in this study were to provide detailed characterizations of the ichthyoplankton assemblage in the autumns of seven years, examine the long-term dynamics of autumn ichthyoplankton assemblages, and evaluate the influence of environmental factors on the spatial distribution and inter-annual variations of ichthyoplankton assemblages associated with the Yangtze Estuary.

Highlights

The Yangtze Estuary, an area of complex and varied environmental conditions, is the link between the Yangtze River and the East China Sea (Luo & Shen, 1994)
This study investigated the response of the ichthyoplankton community to environmental changes in the Yangtze Estuary using canonical correspondence analysis
How to cite this article Zhang et al (2016), Autumn ichthyoplankton assemblage in the Yangtze Estuary shaped by environmental factors

Summary

Introduction

The Yangtze Estuary, an area of complex and varied environmental conditions, is the link between the Yangtze River and the East China Sea (Luo & Shen, 1994). Sea currents in this area are impacted by freshwater input from the Yangtze River, the Huanghai Cold Water Column and the Taiwan Strait Current. Large volumes of nutrients are carried by the river; the Yangtze Estuary has high primary production and rich food resources (Luo & Shen, 1994). How to cite this article Zhang et al (2016), Autumn ichthyoplankton assemblage in the Yangtze Estuary shaped by environmental factors.

Methods

Results

Discussion

Conclusion