The troubling reason why deep ocean mercury is reaching California’s coast

There are many ways for putting toxic mercury into the environment to cause pollution. The most common ways are releasing gaseous mercury into the atmosphere and dump waste into water. When microbes in the seawater absorb mercury, they convert it into a powerful neurotoxin called “methylmercury”, which can be transferred among predators, until it reaches the top of the food chain - human. That’s why scientists pay very close attention to this issue.

                                                                                                      

A recent article in The Washington Post discusses a new study published in Proceedings of the National Academy of Sciences, which suggests that the water in coastal areas can be contaminated by mercury from the fur of seals coming from the ocean. The article describes the results of the research done by Cossaboon and his team at Año Nuevo – the area that elephant seals reside. The research shows that the seawater at Año Nuevo has an eight times higher level of methylmercury than that of other sites along the California coast, and there is a peak during the elephant seal molting season. Researchers then tested the molted fur, and found mercury in it. Giving the fact that elephant seals don’t eat at the coast, it’s reasonable to assume that they carry the mercury all way from the ocean. However, because there have been no obvious signs of other marine organisms being damaged, and Año Nuevo is not used for fishing, it’s still unclear how much impact the mercury in this area have on human.

  Nearshore seawater sampling locations. (A) Locations of Año Nuevo and comparison sites along the Central California coast. (B) Detailed map showing the sampling stations at the south end of the Año Nuevo mainland breeding rookery during the 2012 Northern elephant seal molting season (M1–M6) and 2013 breeding season (B1–B6), as well as the Cove Beach Año Nuevo State Reserve sampling site.

   MeHg and HgT in nearshore unfiltered seawater samples. (A) MeHg concentrations for the Año Nuevo mainland rookery during the 2012 molting season (M1–M6), 2013 breeding season (B1–B6), and Central California comparison sites. (B) HgT concentrations for the rookery during the 2012 molting season, 2013 breeding season, and Central California comparison sites. Error bars (±1 SD) indicate the sample was analyzed at least three times. HgT for B5 (1,650 pM) was considered contaminated and is not graphed.

The study measured the concentration of total Hg (HgT) and methylmercury (MeHg) at Año Nuevo and nearby shores that don’t have great marine mammal populations, respectively. Data showed that the concentrations of HgT at Año Nuevo (3.1~34.0 pM ) and nearby shores (9.2~41.7 pM) had no distinct difference. On the contrary, the MeHg level had an obvious increase at Año Nuevo during molting season (0.28~9.5 pM) compared to that of breeding season (0.39~0.83 pM) and that of nearby shores (0.16~0.41 pM). Scientists then tested the molted fur samples from Northern elephant seals and found that they contained a high level of HgT concentrations, >80% of which are presumed to be MeHg. The results indicate a strong relationship between the increasing concentration of MeHg at Año Nuevo and the molted fur of Northern elephant seals.

One big concern for scientists is that along the shoreline of the U.S. Pacific Coast reside hundreds of thousands of seals and sea lions, all of which have the potential to increase the MeHg concentration in the seawater. So it’s important to understand the mercury cycling in the ocean and its effect on human.

Generally, I think that the article did a good job at objectively summarizing the main idea of the study. It didn’t use exaggerated language to spark unnecessary concern. Also, it pointed out the limitation to the research: Because scientists only tested methylmercury levels in the seawater, instead of other marine organisms, it’s still not clear how much havoc can mercury cause to wildlife and human. However, I think that the author could have used some numbers and simplified figures, instead of conceptual words like “higher” or “increase”, to make the conclusions more intuitive and powerful. For example, putting the concentration levels of total Hg and methylmercury and the diagrams of the comparative tests, which are not hard to be understood by the general public, into the article. Furthermore, the study discussed the role of M. angustirostris, other pinnipeds and marine birds in releasing mercury into the seawater at Año Nuevo, and the reason why their contribution can be ignored. But the author failed to mention these things, which I think could have strengthen the article and help people to understand why molted fur of sea seals are so important and should be pay close attention to.

The Fracking Debate: Does Hydraulic Fracturing Cause Groundwater Contamination?

Hydraulic Fracturing, also referred to as “fracking”, has quickly become a hotly debated topic in the United States. Although high-volume fracking has been used for upwards of 40 years, it has become increasingly popular since the start of the 2000s. Fracking involves the injection of a fluid and proppant (usually a sand-based mixture) into a horizontally drilled well. As the shale cracks, it releases natural gas, which then flows back up the well and can be collected.

            There are numerous concerns with fracking, including increased seismic activity, groundwater and surface water contamination, high water usage, and methane emissions. This article in Nature World News focuses specifically on the main issue of water contamination. The article is titled “Fracking Does Not Contaminate Drinking Water, Yale Study Confirms”, and is focused around an article in the peer-reviewed journal, Proceedings of the National Academy of Sciences (PNAS). The PNAS article is entitled "Elevated levels of diesel range organic compounds in groundwater near Marcellus gas operations are derived from surface activities." 

            The short Nature World News article provides an all-too-brief introduction to the topic and quickly summarizes the study and the findings. Overall, the article actually does a good job of hitting the main points of the study – 64 ground water samples from the Marcellus Shale and the study found no contamination upward migration or lateral transport. The article also includes a statement from one of the researchers that claims they are “not trying to say whether [fracking] is a bad or good thing” and concludes by tying in other recent research about water-usage in fracking processes.

            The original article outlines in greater detail the research done. The study concentrates on only organic compounds, specifically those that are gas and diesel range, and briefly discusses bis(2-ethylhexyl) phthalate. The study focuses on five modes of potential contamination: upward migration from deep formations, lateral transport from faulty wells, leaking oil and gas waste containment ponds, surface spills of hydraulic fracturing chemicals, and leaking underground storage tanks (unrelated to fracking). The article then goes on to disprove all except from surface spills, stating that they are the only possible way for the organic compounds, which were found in drinking water, to have contaminated the wells.

            The main weakness of the news article is it’s biased language. The title implies that the fracking-debate has been settled and that fracking is officially “good”. It seems as though the main goal of the article, which becomes especially evident at the end, is to convince readers that fracking is entirely safe. This tone originates from the peer-reviewed article and is the main reason I do not agree with original article.

            The study has strength in its findings, using the geology and chemistry of the area to refute claims of fracking solution transport through groundwater. I believe that the article took liberties with these findings, however, and used them to make far-reaching claims in language that implied fact. Even though there is a statement from researchers in the online article, nowhere in the original publication is the ability to apply this data to other regions discussed. Geology, and especially groundwater transport, varies greatly from area to area. The study did not do a thorough job in understanding the groundwater transport mechanisms of the region, simply relying on basic transport from point A to point B. In addition, a large variety of fracking fluid mixtures are used, and there is still little regulation in place for the industry. Throughout the original article, the authors consistently use the lack of information as strong evidence towards the argument. In addition, they downplay the severity of surface spillage and contamination. They imply that because a spill is accidental, it does not have the same importance to safety issues in fracking. I know the purpose of the study was specifically to look at belowground contamination, but I think that the authors shouldn’t have downplayed the severity of surface spills, especially since they tend to be underreported and undisclosed.

In summary, the online article agrees with the peer-reviewed article to a fault. Instead of simply stating the findings, both articles go beyond the reach in proving what is true and known about the safety of fracking. A lot of research still needs to be done and it will be many more years before definitive statements can be made about this matter.

The destruction of coral reefs by oxybenzone

Coral reefs are not only important to the oceans and the surrounding aquatic ecosystems, but also to the human population as well.  They deposit the eggs of fish that we eat and protect the coasts during storms.  They are also involved in recreation, particularly tourism considering snorkeling and scuba diving are very popular.  Unfortunately, their populations are drastically decreasing due to water pollution, particularly the pollutant oxybenzone (BP-3) originating from human activity.  In The Washington Post article, journalist Darryl Fears summarizes the Peer Reviewed Article, which identifies sunscreen as the ultimate source of oxybenzone.  The residue of the sunscreen that is found on swimmers remains in the water and eventually sinks deep down and interacts with oceanic organisms.  It particularly affects coral reefs by preventing the coral reefs from their important nutrients and turning the coral reefs from their bright, vibrant colors to white.  Eighty percent of the coral reefs in the Caribbean have been victims to oxybenzone pollution.

Figure 1: Left, picture of coral reef without presence of pollutants. Right, picture of coral reef harmed by oxybenzone.

Found in the journal Archives of Environmental Contamination and Toxicology, the peer reviewed article measured the concentration of BP-3 in the U.S. Virgin Islands and the Hawaiian islands on the coral reef Stylophora pistillata.  "BP-3 is involved in molecular-level to multi-organ system pathologies."  In addition, "chronic exposure to BP-3 in fish resulted in reduced egg production, induction of vitellogenin protein in males, and a significant reduction in egg hatching."  Stylophora pistillata were collected at the Inter-University Institute of Marine Sciences (IUI) in Eilat, Israel. Once collected, they were placed in artificial seawater and exposed to BP-3. Chlorophyll fluorescence was done in order to give an estimate on the extent of bleaching from BP-3.  DNA abasic lesions were quantified in order to see the damage to the species' DNA.  In addition, transmission electron microscopy was conducted and "used for tissue and cellular pathomorphology." Among other methods conducted concerning BP-3's interaction with Stylophora pistillata i.e. statistical models and coral cell toxicity assays, data showed that as the concentration of BP-3 increased, the destruction of the coral reefs increased.



As mentioned earlier, one of the main concerns with the interactions between BP-3 and coral reefs is the corals turning white, coral bleaching.  Bleaching is defined as"the loss of symbiotic dinoflagellate zooxanthellae, photosynthetic pigments, or both."  In other words, it's the loss of pigmentation in coral reefs.  Coral bleaching not only results from water pollution, but it is also affected by greenhouse gases as well.  Despite the fact that the research study mainly focuses on pollutants, heat stress is referenced to harm coral reefs. As we have learned in class, global warming is still on the rise as well as the concentration of greenhouse gases. The oceans therefore have a higher temperature due to global warming, and this heat is harming the coral reef habitat.  Therefore, it is more difficult to stop the destruction of coral reefs as both accumulation of BP-3 and greenhouse gases are involved.

I think Fears' article could have gone into more detail discussing the methods in which the researchers determined BP-3's destruction to the coral reefs. Basically, Fears only included the objective and the conclusion of the study in his article. In my opinion, this article can be strengthened by not necessarily going into massive detail about the methods, but acknowledging the certain techniques pursued, like how DNA lesions were measured, light and darkness was an experimental variable due BP-3's photo-toxicity, etc.  In addition, when Fears writes that "the world is in the midst of a third global coral bleaching event," I think he should go on to define coral bleaching and give a past analysis of the previous two global coral bleaching events. This declaration defines a key global concern, and deserves more attention on it rather than just one sentence.  However, despite these objections, the article definitely got the point across that oxybenzone, found in sunscreen, is seriously harming coral reefs.  I also appreciate that the Washington Post article references alternative sunscreens with no oxybenzone as a step that we can start with towards stopping the concentrations of BP-3 from further increasing in oceans.  The research study itself is intriguing and straightforward with explaining the objective, the experiments, and the data and analysis gathered.  Its strength results from the explanation of why studying the destruction of coral reefs is important and it's relationship with global warming.

Marine food chains at risk of collapse, extensive study of world's oceans finds

An article by Oliver Milman in The Guardian describes a recent study published in PNAs  by Ivan Nagelkerken (Access through U-M Library) about how carbon dioxide is changing marine ecosystems.

The study done by Ivan was conducted out of the need to create awareness about how we are changing the world we live in and how certain changes in our oceans can affect the inhabitants surrounding oceans. The study focuses on many aspects that are involved with carbon dioxide and various aquatic species. The meta-analysis methodology that attributes to most of the data comes from various articles, studies, and experiments tailored to their specific needs to find acidified ocean and temperature dependent study's. 

The main goal of the study was to focus on various attributing carbon dioxide factors that effect a species. Using models that focus on ocean acidification, ocean warming and a combination of the two, various categories were implemented to further diversify the results. The data shows the increase of the metabolism of various animals, this increase effects other species that relies heavily to nourish it. This effects the ability to meet the demand for species with high metabolisms. Shown by mean effect size the foraging and metabolic rates are increasing as both acidification and temperature increase. Ocean acidification factors such as pH, effect calcifying and non-calcifying species (ex. Coral,sponges) showing a decrease in population. The data  goes further with acidification, by agreeing that this is an apparent problem but is concerned with other aspects such as secondary production.

Figure 1 below presents a great summary of how each factor attributes to the growing impact of carbon dioxide. Each levels problems are summed up by either an increase or decrease and depending on the effect dictated by external factors. If this article went further in the analysis it would be valuable to see data about major fishing economies are going to be effected as time progresses. Fishing countries such as Japan would be devastated if there is barely any fishing occurring.

 

Figure 1.Conceptual diagram illustrating the main effects of ocean acidification, warming, and their combination on ecosystem processes and species groups, based on the metaanalysis results as shown in the various figures of our study. Circled arrows indicate the direction of change, and question marks (?) indicate less certain responses. The most likely feedback responses that exacerbate the direct effects of these two global stressors are indicated with white arrows. Two model

ecosystems are shown here (reefs and surface-ocean) to visually capture potential change [present day (Upper Left and Upper Right) vs. future (Lower Left and Lower Right)] in species abundance, species diversity, and community shifts, as revealed by our metaanalysis for ecosystems in general. The changes shown here for reefs and surface-ocean are not exact outcomes of future states but merely emphasize overall responses for (relative) abundance of species.

The article presents a good representation of the study done and presents in a manner that is vital to the key argument. It highlights many of the problems that results from global warming. Attributing factors such as acidity and pH imbalance of oceans, further breakdown each process so the reader receives the full impact of what is happening. However, most of the time the article attempts to talk about too many ideas and switches topics, at times one can get lost about where certain topics are going. There is the lack of important figures that are left, these figures provide a better understanding of the magnitude of each system.  The Guardian article includes majority of the attributing facts that are within the PNA article, in addition it also thinks about other research that is also effecting the oceans. By mentioning melting of Antarctic ice in the near future there is more depth to the understanding of what the article is trying to convey to the reader. What the article takes time to explain is taking each aspects problems and relating them to how certain species will change. By listing examples of oysters, fish, shrimp and a variety of other aquatic animals sets the conditions to make it relatable. Towards the end of the article it presents the problems that will occur if the ocean's ecosystem ceases to exist, but by thinking of how to reduce pollution and reducing the market for fishing we can alleviate the problem. Its thinking on both a local and global scale and countries that have a high market in the fishing industry are the ones that will suffer first.

There are certain complications associated with the Guardian Article. For example, when Milman mentions the topic of hypoxia he mentions the key information that the study provided but leaves much of the key details about how many species will be "challenged". This provides less of an impact on the reader and just leaves questions about how will the species survive and what can it expect to go through. 
Overall the article provides relevant facts that are in line with the paper and provide general understanding of the effects of carbon dioxide on local and global scales and provides enough background information so the reader understands each aspect.

Extreme heatwaves could push Gulf climate beyond human endurance, study shows

A recent news article published in The Guardian by Damian Carrington highlights a study published in Nature Climate Change on the future habitability of the Arabian Gulf. The climate study examined the influence of climate change from greenhouse gasses on the region. The Guardian article ends with an additional contribution from Guardian Middle East reporter Kareem Shaheen focusing on current living conditions of living in Dubai. 

The scientific study is motivated by the need for additional resolution on global climate model projections. To accomplish this, the study focused on the Arabian Gulf with a model of a resolution step size of 25-km grid spacing. Using modeling techniques bench-marked for the region, the study effectively added 30 points of measurement for each one point used in global models for increased resolution. Using a measure reflecting the humidity and temperature of the region, wet-bulb temperature (TW), a direct relationship to a human body's core temperature and survival limits (35 C  for 6 hours) were used to assess habitability of the region. 

The study presents three cases of TW in the Gulf to illustrate their point; a historical TW, mitigated anthropogenic greenhouse gas emissions (RCP4.5), and "business-as-usual" greenhouse gas emissions (RCP8.5). With the current "business-as-usual" model, high TW are obtained for cities on the Arabian Gulf that have southeast winds blowing hot humid air blowing into them including Abu Dhabi, Dubai and Doha. The study warns of temperature increases in the region would reach extremes hazardous to human health, particularly the to "the weakest-namely children and the elderly." The authors do stress the implications of the higher temperatures in other regions of the Middle East such as on the Red Sea coast and warn of the potential health concerns to the Muslim ritual of Hajj that includes annually ~ 2 million pilgrims praying outdoors from sunrise to sunset. The authors of the study emphasize that with mitigated release of greenhouse gases, a smaller increase in TW is obtained. 

The Nature Climate Change article admits in their conclusion that the economic benefits of an oil producing nation provide benefits that allow for more human adaptive processes to combat the health consequences of heating (ie air conditioners). They do warn that under these conditions even the most "basic outdoor activities are likely to be severely impacted." The Nature Climate Change authors do highlight the greater risk for areas not benefiting from oil production, such as coastal Yemen. The authors compare the future climate of the region to the African land portion of the Red Sea, which due to harsh climate has no permanent human settlements. 

 Figure 1: Spatial distributions of extreme wet bulb temperature and extreme temperature.

a–f, Ensemble average of the 30-year maximum TWmax (a–c) and Tmax (d–f) temperatures for each GHG scenario: historical (a,d), RCP4.5 (b,e) and RCP8.5 (c,f). Averages for the domain excluding the buffer zone (DOM), land excluding the buffer zone (LND) and the Arabian Peninsula (AP) are indicated in each plot. TWmax and Tmax are the maximum daily values averaged over a 6-h window.

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Figure 2: Time series of the annual maximum TWmax for each ensemble member and GHG scenario.

Blue, green and red lines represent the historical (1976–2005), RCP4.5 (2071–2100) and RCP8.5 (2071–2100) scenarios, respectively. TWmax is the maximum daily value averaged over a 6-h window. The background image was obtained from NASA Visible Earth.

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The Guardian does a fair representation of the scientific article and presents a easily accessible article to a general audience. However, the original research article was particularly readable for a general audience as well. The Guardian article does a good job putting the discussion of the results into context, by reporting the effects of past heatwaves. However the article does appear to sensationalize when claiming "The study shows the extreme heatwaves, more intense than anything ever experienced on Earth." This may be true for including the presence of humans, but would not be the hottest geological period. In fairness the Guardian article . It accurately reflects the contributions of both heat and humidity to the scientific article's use of wet-bulb temperature. The Guardian also has a nice highlight of what contributing factors make the region particularly susceptible to increased wet-bulb temperatures: shallow warming waters in the Gulf causing higher humidity for coastal regions. Carrington argues that this data should drive the oil producing nations in the region to forgo their practices of hampering greenhouse emission regulations.  

The Guardian article ends with a personal account of living conditions in the city of Dubai by Kareem Shaeen. The description reflects the fact that day to day life already is influenced by climate. This leaves the reader to infer the drastic changes to millions of individuals from the impacts of anthropogenic climate change in the region. Depending on whether the reader came to the article looking for the findings of a science article or as a general interest piece on the influence of climate change on peoples lives, I anticipate mixed reviews. 

Increased Extreme Weather due to Climate Change?

      

             Climate change is one of the most pressing issues for mankind in the 21^st century. This problem is primarily due to human use of fossil fuels which releases compounds like CO₂ and CH₄. These gases absorb and emit infrared radiation which warms the earth in what is called the greenhouse effect. Since humans are releasing massive amounts of greenhouse gases, the amount and rate of warming is rapidly increasing. This will most likely lead to massive consequences for mankind like increased sea level, extreme weather events, and hotter summers.

            An article published earlier this year by the Guardian, “Extreme weather already on increase due to climate change, study finds”, focuses on the effects of global warming to precipitation and heat wave patterns. The author drew his information from a study published in Nature Climate Change. The Guardian article starts off by linking recent increases in heat waves and heavy rain to climate change. It talks about the 0.85 Celsius increase in temperature from the start of the industrial age to today, which has resulted in extreme weather events happening 5 times more than before. The article also mentions the danger of higher increases in temperature, which the world seems on track to follow because of the continued use of fossil fuels. The rest of the piece focuses on the modeling of future extreme weather events and its link to human causes.

            The study in which the Guardian article is based on goes into more detail regarding modeling future extreme weather. It uses probability ratio (PR) and FAR which determines the changed factor of extreme weather events occurring and the percent of these attributable to humans. The study also uses a global model which shows variability in climate and extreme weather events. The data shows that as temperature increases the FAR and PR ratio increase nonlinearly for extreme heat waves and heavy precipitation. The data also shows that overall precipitation can decrease while extreme precipitation events increase in certain circumstances. The last subject the study broaches is the uncertainty of the models that they are using and the methods they used to decrease it like looking at things globally.

Figure 3 from study which shows probability ratio (PR)

            The article did a pretty good job in communicating the major details from the study. For example, the author notes that the attribution of extreme weather events to climate change is a complicated issue. However, I thought that the author could have stated even more clearly that you could not link one extreme weather event directly to only human causes. The author could have also explained FAR to explain attribution science into more detail. Other than that the article did a good job in noting the variability of extreme weather events across the globe and mentions that some places will be more vulnerable to these occurrences.

            Overall, I thought the Guardian article did a good job in representing the material from the study. I was especially pleased of how the article did not go into the political sphere with any comments.   

                                                                                                

Guardian Article

http://www.theguardian.com/environment/2015/apr/27/extreme-weather-already-on-increase-due-to-climate-change-study-finds

Nature Climate Change article

http://dl2af5jf3e.search.serialssolutions.com/?ctx_ver=Z39.88-2004&ctx_enc=info%3Aofi%2Fenc%3AUTF-8&rfr_id=info:sid/summon.serialssolutions.com&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Anthropogenic+contribution+to+global+occurrence%C2%A0of+heavy-precipitation+and%C2%A0high-temperature+extremes&rft.jtitle=Nature+Climate+Change&rft.au=Fischer%2C+E.+M&rft.au=Knutti%2C+R&rft.date=2015-04-27&rft.issn=1758-678X&rft.eissn=1758-6798&rft_id=info:doi/10.1038%2Fnclimate2617&rft.externalDBID=n%2Fa&rft.externalDocID=10_1038_nclimate2617

or

http://www.lib.umich.edu/articles/search?kw=Anthropogenic%20contribution%20to%20global%20occurrence%20of%20heavy-precipitation%20and%20high-temperature%20extremes (click on first article)