Functional Trait Responses of Macrobenthos to Anthropogenic Pressure in Three Temperate Intertidal Communities

Jian-Yu Dong,Linlin Zhao,Xin Sun,Xiumei Zhang,Xiaolong Yang

doi:10.3389/fmars.2021.756814

Abstract

With the increasing impact of human activities on marine ecosystems, there is a growing need to assess how the components of marine ecosystems (e.g., macrobenthos) respond to these anthropogenic pressures. In this work, the trait-based approach was used to assess the effects of anthropogenic pressures represented by the area of land-based aquaculture pond (Pond Area) and heavy metals on the macrobenthic communities in three intertidal zones[Aoshan Bay (AO), Wenquan River and Daren River (RW), and Xiaodao Bay (XD)] of Laoshan Bay, Shandong Peninsula, China. Compared with RW and XD, AO was under more pressure in terms of the average concentrations of heavy metals and total organic carbon (TOC) in sediments and also in the Pond Area. Fuzzy correspondence analysis (FCA) showed that there were significant differences in the composition of functional traits among the three regions (PERMANOVA; p &lt; 0.05). In the highly polluted area, macrobenthic communities exhibited a combination of traits, such as relatively short life span, weak mobility, feeding on deposits, and more tolerant to organic matter, whereas in a less polluted area, they exhibited a combination of traits, such as relatively long life span, relatively high mobility, and more sensitivity to organic matter. The RDA results showed that the distribution of the trait modalities was significantly affected by heavy metals (Hg and Cd), TOC, Pond Area, and sampled location. Variation partitioning analysis (VPA) indicated that the shared influence of sediment-related pollution factors and Pond Area contributed most to the variance of the functional traits, which implied that human activities directly and/or indirectly lead to changes in functional traits of macrobenthic communities in the intertidal zones.

Highlights

The marine macrobenthos community is a critical component and reliable indicator of the biotic integrity of marine ecosystems, especially the intertidal ecosystems (Teixeira et al, 2009; Piló et al, 2016; Llanos et al, 2020)
A total of 50 different taxa were identified in the intertidal zone of Laoshan Bay, of which polychaetes were the most abundant, with a total of 23 species, followed by mollusks (14 species) and crustaceans (10 species), and three species belonged to other taxonomic groups (Supplementary Table 1)
The results of this study suggested that the functional-based approach based on the trait-based matrix can efficiently evaluate the effects of anthropogenic pressure, represented by heavy metals and land-based ponds on the intertidal macrobenthic communities in Laoshan Bay, as previously shown in the intertidal zone (Llanos et al, 2020), subtidal zones (Dong et al, 2021), estuary (Piló et al, 2016), and lagoon (Hu et al, 2019)

Summary

Introduction

The marine macrobenthos community is a critical component and reliable indicator of the biotic integrity of marine ecosystems, especially the intertidal ecosystems (Teixeira et al, 2009; Piló et al, 2016; Llanos et al, 2020). On the Macrobenthos Response to Anthropogenic Disturbance other hand, macrobenthos is relatively sedentary and reflects the ambient conditions of sediments, in which many pollutants (e.g., heavy metals and organic enrichment) are partitioned (Ryu et al, 2011; Desrosiers et al, 2019). Heavy metal contaminants can result in adverse toxic effects on benthic organisms (Dewitt et al, 1996; Dabney et al, 2018), leading to the changes in composition, structure, and ecosystem function of macrobenthic communities (Mucha et al, 2003; Piló et al, 2016; Hu et al, 2019; Roe et al, 2020; Dreujou et al, 2021). Most of the studies were conducted in the subtidal zones other than intertidal zones, which are more vulnerable to human activities

Methods

Results

Discussion

Conclusion