Special Issue "Mercury Biogeochemical Cycle in A Changing World"

A special issue of Geosciences (ISSN 2076-3263). This special issue belongs to the section "Geochemistry".

Deadline for manuscript submissions: closed (30 August 2018)

Special Issue Editor

Guest Editor
Dr. Andrea Garcia Bravo

Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Spanish National Research Council (CSIC), E-08034 Barcelona - Spain
Website | E-Mail
Interests: mercury, biogeochemistry, lakes, ponds, reservoirs, forest

Special Issue Information

Dear Colleagues,

Mercury is a potent neurotoxine. About 130 countries signed the Minamata Convention to reduce Hg emissions and to protect human health and the environment from its adverse effects. Understanding the biogeochemical factors controlling the fate of Hg is thus crucial to determine whether the reduction of Hg emissions might translate into decreases in Hg in aquatic systems and to predict future Hg and methylmercury concentrations in the environment and biota. Currently, there are still substancial knowledge gaps on current sources, speciation, fate and bioaccumulation of Hg in aquatic and terrestrial environments at a global scale. Papers for this Special issue may address novel aspects on processes driving Hg emissions, transformations and transport across terrestrial and aquatic ecosystems at a range of scales from the individual catchment to continents and oceans. Contributions that link these processes to risks for human health (i.e. food safety) are also encouraged. Studies may focus on local, regional, or global scales and Hg exposure to humans or other organisms in the environment.

Dr. Andrea Garcia Bravo
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Geosciences is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 850 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Mercury
  • Methylmercury
  • Processes
  • Emissions
  • Pollution
  • Risk

Published Papers (4 papers)

View options order results:
result details:
Displaying articles 1-4
Export citation of selected articles as:

Research

Open AccessArticle Algal Bloom Exacerbates Hydrogen Sulfide and Methylmercury Contamination in the Emblematic High-Altitude Lake Titicaca
Geosciences 2018, 8(12), 438; https://doi.org/10.3390/geosciences8120438
Received: 29 September 2018 / Revised: 12 November 2018 / Accepted: 22 November 2018 / Published: 26 November 2018
PDF Full-text (2909 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Algal blooms occurrence is increasing around the globe. However, algal blooms are uncommon in dominantly oligotrophic high-altitude lakes. Lake Titicaca, the largest freshwater lake in South America, located at 3809 m above the sea level, experienced its first recorded algal bloom covering a [...] Read more.
Algal blooms occurrence is increasing around the globe. However, algal blooms are uncommon in dominantly oligotrophic high-altitude lakes. Lake Titicaca, the largest freshwater lake in South America, located at 3809 m above the sea level, experienced its first recorded algal bloom covering a large fraction of its southern shallow basin in March–April 2015. The dominant algae involved in the bloom was Carteria sp. Water geochemistry changed during the bloom with a simultaneous alkalinization in heterotrophic parts of the lake and acidification in eutrophic shallow areas. A decrease in oxygen saturation (from 105 to 51%), and a dramatic increase in hydrogen sulfide (H2S) concentrations (from <0.02 to up to 155 µg∙L−1) resulted in the massive death of pelagic organisms. Such changes were brought by the exacerbated activity of sulfate-reducing bacteria (SRB) in this sulfate-rich lake. Although levels in total mercury remained stable during the event, MMHg % rose, highlighting higher conservation of produced MMHg in the water. Such an increase on MMHg % has the potential to produce exponential changes on MMHg concentrations at the end food web due to the biomagnification process. Our physicochemical and climatological data suggest that unusually intense rain events released large amounts of nutrients from the watershed and triggered the bloom. The observed bloom offers a hint for possible scenarios for the lake if pollution and climate change continue to follow the same trend. Such a scenario may have significant impacts on the most valuable fish source in the Andean region and the largest freshwater Lake in South America. Furthermore, the event illustrates a possible fate of high altitude environments subjected to eutrophication. Full article
(This article belongs to the Special Issue Mercury Biogeochemical Cycle in A Changing World)
Figures

Figure 1

Open AccessArticle Molecular Effects of Inorganic and Methyl Mercury in Aquatic Primary Producers: Comparing Impact to A Macrophyte and A Green Microalga in Controlled Conditions
Geosciences 2018, 8(11), 393; https://doi.org/10.3390/geosciences8110393
Received: 30 August 2018 / Revised: 10 October 2018 / Accepted: 23 October 2018 / Published: 29 October 2018
Cited by 1 | PDF Full-text (1804 KB) | HTML Full-text | XML Full-text
Abstract
Mercury (Hg) remains hazardous in aquatic environments, because of its toxicity and high biomagnification in food webs. In phytoplankton and macrophytes, Hg compounds at high concentration have been reported to affect the growth, photosynthesis, and nutrient metabolism, as well as to induce oxidative [...] Read more.
Mercury (Hg) remains hazardous in aquatic environments, because of its toxicity and high biomagnification in food webs. In phytoplankton and macrophytes, Hg compounds at high concentration have been reported to affect the growth, photosynthesis, and nutrient metabolism, as well as to induce oxidative stress and damage. Here, we reviewed the recent knowledge gained on cellular toxicity of inorganic and methyl Hg (IHg; MeHg) in aquatic primary producers at more relevant environmental concentrations, with a particular focus on omics data. In addition, we compared a case study conducted with transcriptomic on the green microalga Chlamydomonas reinhardtii and the macrophyte Elodea nuttallii. At lower concentrations, IHg and MeHg influenced similar gene categories, including energy metabolism, cell structure, and nutrition. In addition, genes involved in the cell motility in the microalgae, and in hormone metabolism in the macrophyte were regulated. At equivalent intracellular concentration, MeHg regulated more genes than IHg supporting a higher molecular impact of the former. At the organism level in C. reinhardtii, MeHg increased reactive oxygen species, while both IHg and MeHg increased photosynthesis efficiency, whereas in E. nuttallii MeHg induced anti-oxidant responses and IHg reduced chlorophyll content. Data showed differences, according to species and characteristics of life cycle, in responses at the gene and cellular levels, but evidenced a higher molecular impact of MeHg than IHg and different cellular toxicity pathways in aquatic primary producers. Full article
(This article belongs to the Special Issue Mercury Biogeochemical Cycle in A Changing World)
Figures

Figure 1

Open AccessArticle The Role of Climate: 71 ka of Atmospheric Mercury Deposition in the Southern Hemisphere Recorded by Rano Aroi Mire, Easter Island (Chile)
Geosciences 2018, 8(10), 374; https://doi.org/10.3390/geosciences8100374
Received: 27 August 2018 / Revised: 28 September 2018 / Accepted: 7 October 2018 / Published: 11 October 2018
PDF Full-text (2551 KB) | HTML Full-text | XML Full-text
Abstract
The study of mercury accumulation in peat cores provides an excellent opportunity to improve the knowledge on mercury cycling and depositional processes at remote locations far from pollution sources. We analyzed mercury concentrations in 150 peat samples from two cores from Rano Aroi [...] Read more.
The study of mercury accumulation in peat cores provides an excellent opportunity to improve the knowledge on mercury cycling and depositional processes at remote locations far from pollution sources. We analyzed mercury concentrations in 150 peat samples from two cores from Rano Aroi (Easter Island, 27° S) and in selected vegetation samples of present-day flora of the island, in order to characterize the mercury cycling for the last ~71 ka BP. The mercury concentrations showed values ranging between 35 and 200 ng g−1, except for a large maxima (~1000 ng g−1) which occurred at the end of the Last Glacial Maximum (LGM, ~20 ka cal BP) in both peat cores. Low temperatures during the LGM would accelerate the atmospheric oxidation of Hg(0) to divalent mercury that, coupled with higher rainfall during this period, most likely resulted in a very efficient surface deposition of atmospheric mercury. Two exceptional short-lived Hg peaks occurred during the Holocene at 8.5 (350 ng g−1) and 4.7 (1000 ng g−1) ka cal BP. These values are higher than those recorded in most peat records belonging to the industrial period, highlighting that natural factors played a significant role in Hg accumulation—sometimes even more so than anthropogenic sources. Our results suggest that wet deposition, linked to atmospheric oxidation, was the main process controlling the short-lived Hg events, both in the mire and in the catchment soils. Full article
(This article belongs to the Special Issue Mercury Biogeochemical Cycle in A Changing World)
Figures

Graphical abstract

Open AccessArticle Prediction of Holocene Mercury Accumulation Trends by Combining Palynological and Geochemical Records of Lake Sediments (Black Forest, Germany)
Geosciences 2018, 8(10), 358; https://doi.org/10.3390/geosciences8100358
Received: 17 August 2018 / Revised: 30 August 2018 / Accepted: 11 September 2018 / Published: 21 September 2018
PDF Full-text (2644 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Forest vegetation plays a key role in the cycling of mercury (Hg) and organic matter (OM) in terrestrial ecosystems. Litterfall has been indicated as the major transport vector of atmospheric Hg to forest soils, which is eventually transported and stored in the sediments [...] Read more.
Forest vegetation plays a key role in the cycling of mercury (Hg) and organic matter (OM) in terrestrial ecosystems. Litterfall has been indicated as the major transport vector of atmospheric Hg to forest soils, which is eventually transported and stored in the sediments of forest lakes. Hence, it is important to understand how changes in forest vegetation affect Hg in soil and its biogeochemical cycling in lake systems. We investigated the pollen records and the geochemical compositions of sediments from two lakes (Schurmsee and Glaswaldsee) in the Black Forest (Germany) to evaluate whether long-term shifts in forest vegetation induced by climate or land use influenced Hg accumulation in the lakes. We were particularly interested to determine whether coniferous forests were associated with a larger export of Hg to aquatic systems than deciduous forests. Principal components analysis followed by principal component regression enabled us to describe the evolution of the weight of the latent processes determining the accumulation of Hg over time. Our results emphasize that the in-lake uptake of Hg during warm climate periods, soil erosion after deforestation and emissions from mining and other human activities triggered changes in Hg accumulation during the Holocene stronger than the changes caused by forest vegetation alone. Full article
(This article belongs to the Special Issue Mercury Biogeochemical Cycle in A Changing World)
Figures

Graphical abstract

Geosciences EISSN 2076-3263 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top