Mercury species accumulation and distribution in Typha domingensis under real field conditions (Almadén, Spain)

Abstract

Monomethylmercury (MeHg) is one of the most toxic and the most commonly occurring organomercury compound and the wetlands are one of the main areas of generation of this Hg form. Concretely, it is in the macrophyte root system where better conditions are given for its generation. However, the knowledge of absorption and subsequent distribution of mercury (Hg) and monomethylmercury in aquatic plants is still limited. Mercury mining district such as Almadén (Ciudad Real, Spain) is a natural laboratory where different rivers flow and the species Typha domingensis Pers. is a common macrophyte which grows in their riverbanks. The aim of the present work is to apply a recently developed method specially designed to analyze Hg species in plant tissues to the different fractions of T. domingensis under real field conditions and to study the accumulation and distribution of Hg species (inorganic Hg and MeHg) within the plant. The results proved that whatever Hg species has preference to be accumulated in the belowground fractions and demonstrated a high efficiency in the accumulation of MeHg.

Molecular Effects of Inorganic and Methyl Mercury in Aquatic Primary Producers: Comparing Impact to A Macrophyte and A Green Microalga in Controlled Conditions

“…This difference in uptake might be due to different life forms (floating vs. benthic) or/and different uptake capacities. Recently, authors measured close to 6 µg•g −1 dw THg in roots of Typha domingensis collected in Valdeazogues River (Spain) ( [24]). Overall, reported data from the field of ratio of uptaken Hg to measured Hg in the exposure water (L•kg −1 ) present log 10 values between 4 and 6 for both macrophytes and phytoplankton ( [4,19,22]), suggesting important bioaccumulation potential and evidencing the importance of Hg uptake in primary producers for its further trophic transfer.…”

Molecular Effects, Speciation, and Competition of Inorganic and Methyl Mercury in the Aquatic Plant Elodea nuttallii

“…Freshwater ecosystems remain currently affected by Hg pollution worldwide, despite past and ongoing efforts to reduce anthropogenic emissions of Hg . Aquatic plants have a key ecological role in shallow water ecosystems and are instrumental for Hg transfer to top consumers in food webs. − For example, the macrophytes Elodea nuttallii and Typha domingensis showed high Hg accumulation from both sediments and water column. − Hg accumulated in plants can affect their fitness and life cycle. In macrophytes, frequently reported toxic effects of Hg include the generation of oxidative stress, such as increased lipid peroxidation and altered activity of enzymes involved in the regulation of reactive oxygen species (ROS). − At the organism level, inorganic Hg (IHg) inhibited root growth in rice seedlings .…”

Effects of illegal gold mining on Hg concentrations in water, Pistia stratiotes, suspended particulate matter, and bottom sediments of two impacted rivers (Paraíba do Sul River and Muriaé River), Southeastern, Brazil

“…This was expected, since the roots of these macrophytes are in direct contact with the water column and have a high surface area to adsorb Hg-rich particles (Molisani et al, 2006 ). The higher Hg accumulation in the roots of macrophytes is a protective strategy, since the restriction of Hg transport to the aerial parts prevents possible damage to the photosynthetic apparatus (Lominchar et al, 2019 ). This not only indicates that Hg is mostly accumulated in the roots, but also that it can enter the food chain through ingestion, especially by herbivorous fish (Súarez et al, 2001 ).…”