Organochlorine Pesticides in Sediment of Zhang River Estuary Mangrove National Natural Reserve: The Implication of Its Source Change in China’s Mangroves

Kai Chen,Bihua Qian,Canrong Qiu,Yun Wang,Xiaoyan Liu,Bin Chen,Jionghui Sun,Xiaomeng Li,Hongwei Ke,Minggang Cai,Shuiying Huang

doi:10.3390/su12073016

Abstract

Seventeen organochlorine pesticides (OCPs) were examined in surface sediments from Zhang River Estuary Mangrove National Natural Reserve, which is situated in the Fujian province in southeast China. The range of ∑OCPs concentration was 0.29–25.41 ng/g dry weight (average 4.53 ng/g), ∑HCHs was 0.008–0.906 ng/g dry weight (average 0.240 ng/g), and ∑DDTs was ND–4.743 (average 0.664 ng/g). The concentrations of the HCH isomers were observed in the following decreasing order: α-HCH > β-HCH > δ-HCH > γ-HCH, and that of the DDT isomers were as in the following order: p,p’-DDT > p,p’-DDE > p,p’-DDD. According to the analysis of the isomer ratios, γ-HCH (lindane) and endosulfan were rarely used recently around this mangrove forest. Instead, the ratios of (DDD+DDE)/DDT showed that DDTs were still illegally used. Compared with other mangroves in China, the residue level and ecological risk of the OCPs in surface sediment from ZREMNNR are both at a low level. Based on stepwise regression analysis, current fruit planting, as well as mariculture in developed areas and vegetable planting in developing areas, had a positive relation with DDT residues in mangrove sediment in China. Oppositely, HCH residues in mangrove sediment were derived from historical consumption, and generally the higher levels occurred in the developed areas. Through this study, we help to close the knowledge gap of OCPs in China’s mangroves and provide a possible management implication for sustainable development in the future.

Highlights

Mangroves are characteristic plants growing in the tropical and subtropical intertidal zones around the world
The highest organochlorine pesticides (OCPs) concentrations were detected at the stations (#8 and #9) that where located at the edge of the mangroves facing the sedimentary zone, and the stations that faced the river channel followed
17 organochlorine pesticides in surface sediment from Zhang River Estuary Mangrove National Natural Reserve (ZREMNNR) were detected, and HCHs, dieldrin, β-endosulfan, endrin aldehyde, DDTs, and endosulfan sulfate accounted for approximately 61%–99% of the OCPs

Summary

Introduction

Mangroves are characteristic plants growing in the tropical and subtropical intertidal zones around the world. Mangroves provide many ecological services, such as flood protection, biological habitat, carbon fixation, and water purification [1,2]. It is commonly known that mangroves have become one of the most threatened and vulnerable ecosystems with increasing ecological pressure from intensive human activities. Under the actions of tidal flush and food chain transport, those stored pollutants can be transferred from the mangroves to the adjacent ecosystems, and even threaten human health [4,5]. To achieve sustainable development of ecological aspects and socio-economic aspects, it is necessary to understand the situation and source of the pollutants in mangrove ecosystems for future effective management [6,7]

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Results

Conclusion