• Site Map

    All the web pages on the conference website







My Goldschmidt

Role functions

Abstract Details

(2020) Trace Metal Analysis of Coral Skeletons: Anthropogenic Influence on Corals at Ilha Grande Bay (Rio de Janeiro, Brazil)

Pessoa I, Geraldes M & Antonioli L


Sorry, the PDF cannot be displayed on your browser.

Download abstract

13g: Room 4, Tuesday 23rd June 22:30 - 22:33

Listed below are questions that have been submitted by the community that the author will try and cover in their presentation. To submit a question, ensure you are signed in to the website. Authors or session conveners approve questions before they are displayed here.

Submitted by Igor Pessoa on Monday 15th June 23:18
Greetings from Rio, Brazil - this distance gave us the opportunity to be closer. It is time for all those who rely on a healthy world to begin working together. The work that coral reef enthusiasts do every day has never been more important! They rely in part on the generous donations and contributions. You can help protect and conserve the coral reefs, consider make a donation to support the changes for a sustainable future. Looking forward to connect with all of you through the meeting. Cheers

Submitted by Karen Hudson-Edwards on Wednesday 17th June 15:32
Can you briefly outline your results? Are the corals enriched in trace metals?
Hi Karen, I was planning to finish the fieldwork in March. However, due to the Covid outbreak we can’t go back to the study area, the area remains closed. And our lab is still closed. Unfortunately, results are not available yet.

Submitted by Joe Stewart on Wednesday 17th June 17:13
Nice video - the most upbeat soundtrack so far! I have many questions. One of the big problems of linking coral geochem to coral reef protection policy is how you infer seawater chemistry from measured trace metal responses. Your laser tracks show that a trace element increase or decreases with time, but how do you go about converting Pb in cps to Pb/Ca in the coral and then into policy relevant [Pb] in seawater? There is a distinct lack of well-characterised carbonate laser ablation standards in circulation? What standards were used here? NIST glass? Pressed carbonate powder pellets? Are you confident these ablate in the same way as solid coral? What partition coefficient is used to convert to metal concentration in seawater? An inorganic carbonate value? What role do growth rates have in the incorporation of metals mentioned here?
Hi Joe, thanks for sharing your insights! Maybe we need to work with policymakers and negotiate with governments to require permission for these targets. The educational sector has a critical and unique contribution toward accelerating this process. Yes, you are right, impacts of heavy metal pollution in corals are directly linked to the water column, sedimentary deposits from which the metal can be released back in the water, and the pathways that the element is distributed into the environment. Thus, it is of great importance to be able to relate data in samples with the environmental data. In this context, it is also necessary to consider the distinct metal releases from multiple sources, the transportation and distribution by sea currents, as well as the entrapment in the sediment package, and other possible drivers for metal incorporation in the skeletons. Besides the chemical concentration in the water, there are other factors that need to be considered when using corals as environmental proxies to monitor marine pollution: (1) biologic and vital effects on trace element uptake into corals (species niche and physiology, metabolic rates and growth speed), (2) environmental conditions and stress parameters (water temperatures, light levels, seawater nutrients, sedimentation rates, bleaching levels and heat stress), and (3) time of sampling and the duration of the events of pollutants to precisely evaluate the dose and exposition length of toxicants on corals. Metals can occur in polluted water as dissolved elements or adhered to the suspended particulate, having different forms of mobility in the seawater circulating throughout the shoreline zones. When filter-feeding in polluted water, chemicals can accumulate in soft inner coral tissues or are removed from the body by detoxification mechanisms and stored in skeletons. And distinct species, often differ in the temporal ranges and/or temporal resolutions. Thus, a comparison between different species has to consider fractions and physiological processes. The interpretation of data also needs to include the biomineralization processes, which are physiologically very different among distinct species of corals. On top of that, the accuracy and precision in the analysis may be affected by a number of significant factors such as instrumental drift, isotopic fractionation, mass-interferences, matrix effects, and the lack of sufficiently matrix-matched reference materials. These tasks are interrelated and advance on one improves development over the other. On the other hand, industrial managers are thriving by addressing whether the yield of the measurement uncertainties can be improved to obtain precise and accurate results. This topic incorporates many questions; What level of detection limits are necessary to get precise results? Do differences in the limits of detection between different systems affect data interpretation? Do elemental fractionation and mass-load-dependent matrix effects vary significantly between different instruments? A comprehensive strategy is the key to overcoming these challenges and choosing the right methodological approach is critical to achieving accurate and precise results.

Submitted by Marcello Di Bonito on Monday 22nd June 11:36
Dear authors, thank you for the video, which I also found very interesting. I understand from your previous answers that unfortunately results are not available yet, and your exchange with the colleague from Bristol already answered some of my questions. Apart from the instrumental and analytical issues, what do you think of the potential to use bayesian models (e.g., MixSIAR) to address identification of sources? Best wishes, Marcello Di Bonito
Hi Marcello, thanks for this tip! I was in doubt about which statistical model to use. It seems that MixSIAR can disentangle the pollution sources even when it occurs overlapping of isotopic fingerprints from multiple sources. Just how we hope to constrain the specific sources of pollution. Cheers, Igor

Submitted by Miguel Angel Gomez Gonzalez on Monday 22nd June 12:09
Nice video, really illustrative. I have a question in the line of Karen's one. Even though you have not been able to analyze any "real" coral sample yet, could you list the trace elements that you are supposed to find according to the existing literature and/or the nature of the pollution sources (indicated as blue dots in your presentation)? It would be great to have an outline of: 1) what elements are you expecting the coral to be significantly enriched with? and 2) which elemental concentration range would be considered toxic for the coral's survival?
Hi Miguel, the goal is to quantify Barium (Ba), Strontium (Sr), Chromium (Cr), Manganese (Mg), Nickel (Ni), Copper (Cu), Tin (Sn), and Lead (Pb) concentrations inside the corals’ aragonitic skeletons. To address this, measurements will be performed in the skeletons using LA-ICP-MS and LA-MC-ICP-MS techniques. The presence of several anthropogenic sources acting in this region suggests that each source releases distinct amounts of metal content over time, which can be caused by acute pollution and/or diffuse contamination from multiple sources. Anthropogenic activities and potential sources acting in the region are those related to industrial sites (including a nuclear power plant), high input of domestic effluents, harbors, an oil terminal, a maritime mining terminal, dockyards, and several marinas. The area shows intermediate values of heavy metal concentrations in the bottom sediments, while few studies have examined trace metal concentrations in the water column there. A fundamental question of this research is: Can we use skeletons of Tubastraea tagusensis, Tubastraea coccinea, and Mussismilia hispida as proxies of metal pollution at a resolution that can be precisely registered to detect anthropogenic influences? In order to relate the conditions present in the ecosystems and the response of the organisms, it is necessary to develop experiments in the laboratory, with living corals, in which several permits are controlled. Although this is not included in this study. The need for a more robust model to discuss the changing conditions of seawater is crucial for the investigation of threats that affect the health of coral reefs. --- Carilli et al. 2009. Marine Pollution Bulletin. 58 (12), 1835–1842. --- Chen et al. 2015. Journal of Geophysical Research: Oceans 120, 405–416. --- Erftemeijer et al. 2012. Marine Pollution Bulletin. 64 (9), 1737–1765. --- Inoue et al. 2014. Coral Reefs 33 (2), 363–373. --- McCulloch et al. 2003. Nature 421 (6924), 727–730. --- Nguyen et al. 2013. Coral Reefs 32 (1), 181–193. --- Saha et al. 2016. Science of the Total Environment 566–567, 652–684. --- Sowa et al. 2014. PLoS One 9 (2), e88790.

Sign in to ask a question.

Goldschmidt® is a registered trademark of the Geochemical Society and of the European Association of Geochemistry

Website managed and hosted by White Iron Conferences on behalf of the international geochemical community