scholarly journals A biological survey method applied to seafloor massive sulphides (SMS) with contagiously distributed hydrothermal-vent fauna

2012 ◽  
Vol 452 ◽  
pp. 89-107 ◽  
Author(s):  
PC Collins ◽  
R Kennedy ◽  
CL Van Dover
Keyword(s):  
Hydrothermal Vent ◽  
Survey Method ◽  
Biological Survey ◽  
Seafloor Massive Sulphides ◽  
Massive Sulphides

scholarly journals Mining the Deep: A global assessment of biodiversity and research effort at deep-sea hydrothermal vents in relation to mining of seafloor massive sulphides

2019 ◽  
Author(s):  
Andrew Thaler ◽  
Diva Amon
Keyword(s):  
Deep Sea ◽  
Hydrothermal Vent ◽  
Hydrothermal Vents ◽  
Research Effort ◽  
Scientific Discovery ◽  
Precious Metals ◽  
Biogeographic Provinces ◽  
High Concentrations ◽  
Seafloor Massive Sulphides ◽  
Massive Sulphides

When the RV Knorr set sail for the Galapagos Rift in 1977, the scientists aboard expected to find deep-sea hydrothermal vents. What they did not expect to find was life—abundant and unlike anything ever seen before. Submersible dives revealed not only deep-sea hydrothermal vents but entire ecosystem surrounding them, including the towering bright red tubeworms that would become icons of the deep sea. This discovery was so unexpected that the ship carried no biological preservatives. These first specimens were fixed in vodka from the scientists’ private reserves.Since that first discovery, deep-sea hydrothermal vents have been found throughout the oceans. As more regions are explored, newly discovered vent fields present the potential for entirely species and ecosystems. Increasingly, however, it is not scientific discovery, but the financial value of vent fields, and the ores they contain, that is driving exploration in the deep sea. Over the last five decades, a new industry has emerged to explore the potential of mining Seafloor Massive Sulphides (deep-sea hydrothermal vents that contain high concentrations of rare and precious metals). Multiple enterprises are developing mining prospects that include both active and inactive deep-sea hydrothermal vent fields. In order to understand the impacts of exploitation at deep-sea hydrothermal vents, scientists and miners must establish environmental baselines. Biodiversity is frequently used as a proxy for resilience and as a metric for assessing biological baselines but, since research effort is not distributed equally across the oceans, biodiversity estimates in the deep sea are rarely comprehensive. Studies have predominantly focused on a few key biogeographic provinces, while other regions have only been sampled sparingly. Managers, regulators, and mining companies are working from incomplete data, with inferences about the consequences, as well as mitigation and remediation practices, often drawn from studies of few vent ecosystems that are often different from those in which the impacts are expected to occur. To better assess our current understanding of deep-sea hydrothermal vent biodiversity, we undertook a quantitative survey of the last 40 years of vent research. A stark north/south divide was detected, demonstrating that while research was disproportionately focused in the Northern Hemisphere, mining prospects were overwhelmingly positioned in the Southern Hemisphere. In addition, we provided a ranked assessment of biodiversity in eight major biogeographic provinces, identified knowledge gaps in the available deep-sea hydrothermal vent exploration literature, and assessed sampling completeness to provide further guidance to regulators, managers, and contractors as they develop comprehensive environmental baseline assessments.

scholarly journals Microbiological Quality of Ready-to-Eat Leafy Green Salads during Shelf-Life and Home-Refrigeration

Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1421
Author(s):  
Alyexandra Arienzo ◽  
Lorenza Murgia ◽  
Ilaria Fraudentali ◽  
Valentina Gallo ◽  
Riccardo Angelini ◽  
...  
Keyword(s):  
Shelf Life ◽  
Small And Medium Enterprises ◽  
Microbiological Quality ◽  
Survey Method ◽  
National Guidelines ◽  
Salmonella Spp ◽  
Expiry Date ◽  
Mesophilic Bacteria ◽  
Biological Survey

The market of ready-to-eat leafy green salads is experiencing a noticeable growth in Europe. Since they are intended to be consumed without additional treatments, these ready-to-eat products are associated with a high microbiological risk. The aim of this work was to evaluate the microbiological quality and safety of ready-to-eat leafy green salads sold in widespread supermarket chains in Lazio, Italy, on the packaging date during shelf-life and during home-refrigeration. The study also aimed to determine the differences between low-, medium-, and high-cost products. Salmonella spp. and L. monocytogenes were chosen as safety indicators as specified by European regulations while total aerobic mesophilic bacteria and Escherichia coli were chosen as quality indicators as suggested by national guidelines. Analyses were performed following the ISO standards and in parallel for the evaluation of total aerobic mesophilic bacteria, with an alternative colorimetric system, the Micro Biological Survey method, in order to propose a simple, affordable and accurate alternative for testing the microbiological quality of products, especially suitable for small and medium enterprises and on-site analyses. The study revealed high, unsatisfactory, total bacterial loads in all analyzed samples on the packaging date and expiry date and a very high prevalence of Salmonella spp. (67%) regardless of the selected varieties and cost categories; L. monocytogenes was not recovered aligning with the results obtained in other studies.

scholarly journals Geological fate of seafloor massive sulphides at the TAG hydrothermal field (Mid-Atlantic Ridge)

2019 ◽  
Vol 107 ◽  
pp. 903-925 ◽  
Author(s):  
Bramley J. Murton ◽  
Berit Lehrmann ◽  
Adeline M. Dutrieux ◽  
Sofia Martins ◽  
Alba Gil de la Iglesia ◽  
...  
Keyword(s):  
Hydrothermal Field ◽  
Mid Atlantic Ridge ◽  
Seafloor Massive Sulphides ◽  
Massive Sulphides ◽  
Tag Hydrothermal Field

Validation of the Micro Biological Survey Method for Total Viable Count and E. coli in Food Samples

2011 ◽  
Vol 6 (11) ◽  
pp. 951-962 ◽  
Author(s):  
Giorgia Bottini ◽  
Francesca Losito ◽  
Alessio De Ascenti ◽  
Francesca Romana Priolisi ◽  
Alberto Mari ◽  
...  
Keyword(s):  
Food Samples ◽  
Viable Count ◽  
Survey Method ◽  
Total Viable Count ◽  
E Coli ◽  
Biological Survey

scholarly journals Field application of the Micro Biological Survey method for the assessment of the microbiological safety of different water sources in Tanzania

2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Matteo Gionfriddo ◽  
Beatrice Nicolosi ◽  
Lorenza Murgia ◽  
Alyexandra Arienzo ◽  
Laura De Gara ◽  
...  
Keyword(s):  
Developing Countries ◽  
Tap Water ◽  
Water Sources ◽  
Field Application ◽  
Alternative Methods ◽  
Survey Method ◽  
Water Safety ◽  
Biological Survey ◽  
Enteric Infections ◽  
Dug Wells

Access to safe water is stated within human rights as essential for life, as water can be a source of severe enteric infections threatening human health, in particular children from Developing Countries. Along with reference methods, need is pressing for alternative methods to flank reference ones to improve water safety on-site monitoring and in the absence of scientific facilities or even electricity supply. The Micro Biological Survey (MBS) method has already been successfully applied to water safety assessment in Developing Countries. A total of 18 water samples were collected from different sources (rivers, dug wells, tap water) within the Rukwa Region, Tanzania, and underwent analysis for Total Coliforms following the MBS method. Globally, rivers showed more frequently contamination, followed by dug wells, tap water and tanks. Results demonstrate the need for continuous monitoring of water sources, even in difficult frameworks lacking electric supply, to help improve control over water quality, possibly using alternative methods to simplify existing protocols.

scholarly journals Mining seafloor massive sulphides and biodiversity: what is at risk?

2010 ◽  
Vol 68 (2) ◽  
pp. 341-348 ◽  
Author(s):  
Cindy Lee Van Dover
Keyword(s):  
At Risk ◽  
Life Histories ◽  
Hydrothermal Vents ◽  
Test Methods ◽  
Limited Attention ◽  
Conservation Areas ◽  
Conservation Units ◽  
Key Species ◽  
Seafloor Massive Sulphides ◽  
Massive Sulphides

Abstract Van Dover, C. L. 2011. Mining seafloor massive sulphides and biodiversity: what is at risk? – ICES Journal of Marine Science, 68: 341–348. Scientific exploration of the deep sea in the late 1970s led to the discovery of seafloor massive sulphides at hydrothermal vents. More recently, sulphide deposits containing high grades of ore have been discovered in the southwest Pacific. In addition to metal-rich ores, hydrothermal vents host ecosystems based on microbial chemoautotrophic primary production, with endemic invertebrate species adapted in special ways to the vent environment. Although there has been considerable effort to study the biology and ecology of vent systems in the decades since these systems were first discovered, there has been limited attention paid to conservation issues. Three priority recommendations for conservation science at hydrothermal vent settings are identified here: (i) determine the natural conservation units for key species with differing life histories; (ii) identify a set of first principles for the design of preservation reference areas and conservation areas; (iii) develop and test methods for effective mitigation and restoration to enhance the recovery of biodiversity in sulphide systems that may be subject to open-cut mining.

scholarly journals Au and Te Minerals in Seafloor Massive Sulphides from Semyenov-2 Hydrothermal Field, Mid-Atlantic Ridge

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 294 ◽  
Author(s):  
Anna Firstova ◽  
Tamara Stepanova ◽  
Anna Sukhanova ◽  
Georgy Cherkashov ◽  
Irina Poroshina
Keyword(s):  
Low Temperature ◽  
Mean Value ◽  
Hydrothermal Field ◽  
Additional Contribution ◽  
Core Complex ◽  
Mid Atlantic Ridge ◽  
The Mean ◽  
High Concentrations ◽  
Seafloor Massive Sulphides ◽  
Massive Sulphides

The Semyenov-2 hydrothermal field located at 13°31′N of the Mid-Atlantic Ridge (MAR) is associated with an oceanic core complex (OCC) and hosted by peridotites and basalts with minor amounts of gabbro and plagiogranites. Seafloor massive sulphides (SMS) are represented by chimneys with zonality, massive sulphides without zonality and sulphide breccia cemented by opal and aragonite. The mean value of Au (20.6 ppm) and Te (40 ppm) is much higher than average for the MAR SMS deposits (3.2 ppm and 8.0 ppm, respectively). Generally, these high concentrations reflect the presence of a wide diversity of Au and Te minerals associated with major mineral paragenesis: primary native gold, melonite (NiTe2) and tellurobismuthite (Bi2Te3) are related to high-temperature chalcopyrite (~350 °C); electrum (AuAg)1, hessite (Ag2Te) and altaite (PbTe) are related to medium- and low-temperature Zn-sulphide and opal assemblages (260–230 °C). Calaverite (AuTe2) and Te-rich “fahlore” Cu12(Sb,As,Te)4S13 are texturally related to the chalcopyrite-bornite-covellite. Enrichment of Au in sulphide breccia with opal and aragonite cement is driven by the re-deposition and the process of hydrothermal reworking of sulphide. The low-temperature fluid mobilizes gold from primary sulphide, along with Au and Te minerals. As a result, the secondary gold re-precipitate in cement of sulphide breccia. An additional contribution of Au enrichment is the presence of aragonite in the Cu-Zn breccia where the maximal Au content (188 ppm) is reached.

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