Changes in zooplankton communities along a mercury contamination gradient in a coastal lagoon (Ria de Aveiro, Portugal)

Abstract

The main objective of this paper was to evaluate the impact of mercury on the zooplankton communities' structure and functioning and their bioaccumulation patterns along a contamination gradient in a temperate coastal lagoon. Our results demonstrated that total abundance was not negatively affected by Hg contamination, since the most contaminated areas presented the highest values, being the copepod Acartia tonsa the dominant species, which means that it is a very well adapted and tolerant species to mercury. Nevertheless, negative effects were observed in terms of species diversity, since the most contaminated areas presented the lowest values of species richness, evenness and heterogeneity. Moreover, the spatial mercury gradient was reflected on the bioaccumulation patterns of the zooplankton communities. This reinforces the idea that zooplankton can be considered as an important vehicle of mercury transfer through the food pelagic web since it constitutes a primordial food resource for several commercial fish species.

Alleviation of mercury toxicity to a marine copepod under multigenerational exposure by ocean acidification

“…Alternatively, an increased trend for Hg accumulation may be partially related to metallothionein (MT) induction in the copepods, since the maternally exposed animals would prepare to produce more MT to supply more binding sites for the internal metals during mutigenerational exposure 41 . It should be noted that the treated T-Hg contents in this work were comparable with Hg concentrations in several marine copepods in the environment 42–44 , and thus were environmentally relevant.…”

“…Cardoso et al . reported that the most contaminated areas in a temperate coastal lagoon presented the highest Hg accumulation in zooplankton assemblages with the lowest values of species richness, evenness and heterogeneity 42 . In our study, the inhibitory effects of Hg on number of nauplii per clutch was more obvious in the late generations (i.e., F2-F3), likely ascribed to an increased Hg accumulation in the copepod with generations.…”

Impacts of mercury exposure on life history traits of Tigriopus japonicus: Multigeneration effects and recovery from pollution

“…Nevertheless, the detailed mechanism really deserves a further investigation. It should be emphasized that the treated T-Hg contents in our study were within the span of Hg concentrations in several marine copepods in the environment (Cardoso et al, 2013;Hsiao and Fang, 2013;Ritterhoff and Zauke, 1997), hence enabling our study to display an environmentally relevant significance.…”

“…Consequently, it was deduced that Hg pollution can suppress fecundity of the copepods (i.e., population recruitment) and thus potentially affect their community structure and functioning in the marine ecosystem. Cardoso et al (2013) evaluated the impact of Hg on zooplankton community structure and functioning in a temperate coastal lagoon, and reported that the most contaminated areas presented the highest Hg accumulation in zooplankton assemblages (dominated by copepods). It was further reported that these areas also had the lowest values of species richness, evenness and heterogeneity (Cardoso et al, 2013).…”

Spatial and taxonomic variation of mercury concentration in low trophic level fauna from the Mediterranean Sea

“…Previous studies on zooplankton have often focused on size classes or bulk collections of zooplankton (e.g. Bargagli et al 1998; Cardoso et al 2013; Gosnell and Mason 2015; Hammerschmidt et al 2013), rather than individual taxa, which could mask important trophic transfer patterns for fish or birds with specific prey preferences. Studies that have looked at Hg bioaccumulation in particular species rather than size classes have been concentrated in polar regions, particularly the Arctic (Campbell et al 2005; Foster et al 2012; Pucko et al 2014).…”