Data Sourcing & Assessment
References
Delongchamp, Tania M., Lean, David R.S., Ridal, Jeffrey J., & Blais, Jules M. (2009). Sediment mercury dynamics and historical trends of mercury deposition in the St.Lawrence River area of concern near Cornwall, Ontario, Canada. Science of the Total Environment, 13, 4095-4104. doi:10.1016/j.scitotenv.2009.03.010
This is a peer-reviewed article in the journal, Science of the Total Environment. The purpose of this research was to compare historical data of mercury (Hg) pollution in the area of Cornwall, Ontario with newly acquired sediment core samples. Methodology included gathering nine core samples in an ‘Area of Concern'(as designated by the International Joint Commission in 1985) near Cornwall along the St.Lawrence River and determining the amount of Hg within. These samples were then compared with historical records of industry emissions of Hg from 1970-1995. The researchers detail how in the 1970s industry in this area was forced to lower Hg emissions and in the 1990s were eventually closed entirely. The researchers also note that the Hg levels within this area are much higher than the national and provincial sediment criteria for the preservation of aquatic life. Hg Diffusion calculations were used along with statistical analysis to determine core sample site differences. This is a relevant study in that it is was conducted fairly recently, within 10 years and its results show that high levels of mercury are still persisting within river sediment layers. However these levels would have been much higher were industry still able to operate within the Area of Concern. This appears to be a reliable source in that the research was conducted through the University of Ottawa. I would say that the analysis conducted was extensive to say the least however I am surprised that the researchers did not chose to collect more than nine sediment core samples.
Lessard, Charlotte R., Poulain, Alexandre J., Ridal, Jeffrey J., & Blais, Jules M. (2014). Dynamic mass balance model for mercury in the St.Lawrence River near Cornwall, Ontario, Canada. Science of the Total Environment, 500-501, 131-138.
doi: 10.1016/j.scitotenv.2014.08.080
This is another peer-reviewed article from the journal, Science of the Total Environment. It appears to have a few of the same people from the previous reference (Ridal & Blais) and it appears their research goals are complimentary to that and previous studies on mercury(Hg) levels within the region of Cornwall, Ontario. The goal of this study was to generate a dynamic mass balance model that measured total mercury(THg), elemental mercury(Hg0), divalent mercury (Hg2+), methyl mercury(MeHg) concentrations in sediment, water and biota contained in the St.Lawrence River at Cornwall, Ontario and compared it to previous data. The researchers developed this model with a complex software program and used it to estimate emissions pre 1970(before regulations on mercury levels were introduced) and then to also estimate storm sewer discharge. They also stress that making this model which measures three types of mercury may possibly show the risk of bioaccumulation in biota and humans as a result of mercury’s tendency to transfer from sediment, water and air. Three zones of high mercury contaminations along the St.Lawrence River near Cornwall were selected for this study. This research is significant in that the dynamic model that was developed may be used for other river locations along the St.Lawrence and even around the world. Again this study was conducted through the University of Ottawa as was the previous reference. I think a strength of this study is that the dynamic model created using results from previous data ended up showing similar values.
Richman, Lisa A., & Dreier, Susan I.(2000). Sediment Contamination in the St.Lawrence River Along the Cornwall, Ontario Waterfront. Journal of Great Lakes Research, Vol.27, 1, 60-83.
doi: 10.1016/S0380-1330(01)70623-5
Another peer-reviewed article however this time it is from the Journal of Great Lakes Research. It is a case study that compiled contaminated sediment data from the region of Cornwall from 1970-1997. The researchers determined that contaminated sediment with mercury and various metals were mostly due to industry from the area and that the highest concentration of those pollutants was actually downstream rather than at the location of the industrial sites themselves. This is good reference for our project in that the research was conducted shortly after much of the industry in the area subsided in the mid 1990s. This research also provided a foundation that any proceeding study could reference for a similar assessment of polluted sediment in river environments. This study was carried out by the Environmental Monitoring & Reporting Branch of the Ontario Ministry of Environment so it can be considered reliable. Only in the conclusions did the researchers detail how mercury is detrimental to the aquatic food chain when maybe this could have been stated earlier on or even given more notice in the study itself.
Lavoie, Raphael A., Hebert, Craig E., Rail, Jean-Francois, Braune, Birgit M., Yumvihoze, Emmanuel, Hill, Laura G., Lean, David R.S.(2010). Trophic structure and mercury distribution in a Gulf of St.Lawrence(Canada) food web using stable isotop analysis. Science of the Total Environment, Vol.408, Issue 22, 5529-5539
This is the third peer-reviewed article from Science of the Total Environment that I have chosen. This study wanted to find out how mercury is affecting the food web within the Gulf of St.Lawrence. Researchers had numerous experiment sites near and around Corossol Island in Quebec. They examined seabirds, fish, decapods, echinoderms, molluscs, amphipods and zooplankton to measure the portion of mercury within each species type in their respective trophic levels. On top of that they also took water samples. The researchers tried to determine the extent of biomagnification in seabirds since they are on the highest trophic level. Researchers found that THg and MeHg concentrations increased with body size but at the same time decreased with lipid content. This reference is useful to our study because it provides some insight as to how mercury is affecting the wildlife in the St.Lawrence region. It was conducted through the University of Ottawa and Environment of Canada so it can be adjudged as reliable.
The Associated Press.(2013). UN treaty to limit mercury emissions signed by 140 countries. Retreived from http://www.cbc.ca/news/world/un-treaty-to-limit-mercury-emissions-signed-by-140-countries-1.1405350
This is a news article from the Canada Broadcasting Corporation detailing the United Nations plan to introduce an international treaty limiting harmful emissions of mercury. The treaty was adopted by more than 140 nations at the time and it is legally binding to those who sign it. However there appear to be exceptions for the use of mercury in such items as vaccines and products used religious/traditional purposes. I think this article is relevant to our study in that it shows on a global level that the world is trying to eradicate the use mercury. However nowhere in the article does it talk about Canada’s stance nor does it state that Canada was one of the adopters of the treaty. This an article from the CBC website and it providing news on an international matter so it is considered reliable.
Peerenboom, Greg.(2015). PCBs, mercury in St.Lawrence River fish. Retrieved from http://www.standard-freeholder.com/2015/05/05/pcbs-mercury-in-st-lawrence-river-fish
This is a news article Standard-Freeholder news outlet and it describes the 22nd Annual River Symposium and the presentation on how the bullhead-a small catfish species- are showing high levels of mercury and other contaminants. The writer details that Marcel Pinheiro, of the University of Waterloo is conducting the research however his findings are from evidence taken in 2004-05. Although the bullhead isn’t an important recreational fish, Jeff Ridal, the executive director of the St.Lawrence River Institute of Environmental Sciences(he was also credited in aforementioned studies!), stated that the research completed may help track the more substantial but harder to locate walleye fish. This article is relevant to our study because it is showing public concern about the fish that inhabit the St.Lawrence. This article appears to be reliable at first in that it is a news outlet from Cornwall, Ontario as well as having a well known researcher mentioned in the article however there is no reference sources at the end of the article only the writers Twitter handle.
Monitoring the State of the St.Lawrence River, Temporal Changes in Toxic Contamination at the Carillon Sampling Station. St.Lawrence Plan For a Sustainable Development. Government of Canada & the Province of Quebec. Retrieved from http://planstlaurent.qc.ca/fileadmin/site_documents/documents/PDFs_accessibles/Toxiques_Carillon_e_01_FINAL_v1.1.pdf
This is a goverment document that provides data on toxic substances reaching Carillon water sampling station. This document shows tables indicating the levels of harmful metal such as copper, iron, and mercury. It also has detailed graphs displaying dissolved mercury, arsenic and nickel content in the water near the station. This document shows that some government data is released to the public however it is perplexing why only one water stations data is being highlighted and made available.
Monitoring the State of the St.Lawrence River, Toxic Contamination of Marine Resources. St.Lawrence Vision 2000. Government of Canada & the Province of Quebec. Retrieved from http://planstlaurent.qc.ca/fileadmin/site_documents/documents/PDFs_accessibles/Contamination_marine_2002_e_FINAL_v1.1.pdf
This goverment document provides data on toxic substance amount in marine species throughout the Gulf of St.Lawrence. It displays graphs showing concentration of mercury, cadmium and lead in species such as Atlantic Cod, Grey Seal, Snow Crab and Atlantic Herring. The data collection begun in the early 1990s and it was established so to monitor the spatial and temporal fluctuations in contamination of important regional species. This data gives insight as to the length the government is going to determine toxic substance levels in marine life however it is surprising that there isn’t any more recent data available.