Environmental Forensics Based on River Pollution - Case Study Example

Environmental forensics case study based on river pollution Name Institution Date Environmental Forensics Case Study Based On River Pollution Introduction Fish kill is normally characterized by a high number of fish’s death over short time duration, normally within a specific area (Heil et al, 2001). The most common causes of fish kill is decreased oxygen in the water or the change in PH of the water and the reduced oxygen and changed PH can be due to factors river pollution, contamination, algae bloom, change in water temperature, toxicity or even infectious diseases (Allison & Antonietta, 2010). In this case study, a massive fish kill of rainbow trout (Salmo gairdneri) occurred in Styx River, located near Syxton. According to the reports, many dead and dying fish were identified at different locations of Styx River. Reports further indicated that the river’s appearance was darker than usual and there was dirty discolored foam on the surface of the river. The fish kill at Styx River is similar to a fish kill that took place in Atlantic Menhaden in Peconic River where a significant fish kill occurred in 2015. The fish kill in this case study can be attributed to contamination and pollution from different possible sources. Some of the possible sources of contamination and pollution to the river include Riverside Brewery, Styxton Sewage Plant, and ABChemicals. The ABChemicals manufactures methyl-mercury while Riverside Brewery is allowed to release 500 liters of washing waste directly to the river. The waste consists of small quantities of surfactant, yeast and beer in a diluted aqueous phase. Styxton Sewage Plant uses primary and secondary treatments and chlorine as disinfectant and the treated affluent is discharged into Styx River. Accordingly, the objective of this report is to investigate the cause of the fish kill in Styx River and recommend strategies for preventing similar debacles. Possible Contaminants Chlorine Styxton Sewage Plant uses chlorine to disinfect the treated sewage before it returns to Styx River and hence chlorine is a possible contaminant because chlorine can kill fish (Hewlett et al, 2009). To test presence of chlorine, Liquid chemical OTO is used: the color of the water changes to yellow if the water has chlorine. Methyl-mercury Heavy metals such as mercury are major causes of water contamination (Kaur et al, 2011). For instance, in River Tisza in Hungary the contamination of the river was attributed to heavy metals. The color of the water turned black after the mercury spill into River Tisza on 15th March 2000. Similarly, in Styx River the water was darker which is akin to River Tisza’s contamination and therefore methyl-mercury is a possible contamination here: ABChemicals produces methyl-mercury. According to Lusk et al (2005) methyl-mercury can cause death, impair reproduction and growth of aquatic animals. In addition, fish consume mercury and transforms it into poisonous methyl-mercury which is highly toxic. Raw Sewage Styxton Sewage Plant discharges the waste at the Styx River. Sewage contains waste containing water, harmful bacteria and other microbes. Sewage may be a carrier of diseases and toxins from human waste from the Stxyton village and toxins from industrial waste. For instance, in Glastonbury, a sewage leak contaminated the water and fish died from the contamination (Haley, 2016). Surfactants Surfactants refer to substances that industries use in cleaning. Surfactants act through lowering water’s surface tension. ABChemicals discharges in the Styx River and hence may be a source of surfactants. The sewage is also another source of surfactants. According to Heil et al (2001) surfactants are toxic to aquatic life and therefore surfactants are potential cause of the fish kill that occurred in Styx River. Ammonia The sewage and ABChemicals are source of ammonia. Ammonia has toxic effects in the central nervous system and the brain and hence ammonia could have been a possible cause of the fish kill. For example, during a Glastonbury festival, water from a tank leaked into White-lake and aquatic life was affected. After investigations, it was discovered that the White-lake water had high levels of ammonia and this led to adverse effects on the fish. Therefore, ammonia is a possible cause of the fish kill (Haley, 2016). Sampling Step 1 Take water samples from the area adjacent to the dead/dying fish The sample water should be stored in clean bottles and the surface water should be include as well Step 2 Example a number of fish to assess of there is any external abnormalities, for instance skin discoloration or distension of some body parts Step 3 Trace the discharge upstream of the fish kills. Explore all sides of the river and collect all substances that could be suspected to have caused pollution to the river. In addition, it would be important to take samples from the upstream too in order to assess any possible source of contamination because this will help to identify any changes in water quality More importantly, a water sample should be collected from where the river starts. This is because there is less oxygen at the start of the river (Paerl et al, 1999). Sediment samples from the river should also be collected. The sediments should be taken from the river edges since concentration of contaminants reduces as the river gets deeper (Paerl et al, 1999). Analysis Analysis of Heavy Metals Assessment of heavy metals especially mercury is important since ABChemicals is discharges at the river and manufactures methyl-mercury (Lusk et al, 2005). Atomic Absorption Spectrophotometer will be used to evaluate the concentration of mercury in the water samples. Use Winkler Titration to Measure Dissolved Oxygen Winkler titration is used in measuring the concentration of dissolved oxygen in water samples. The procedure involves addition of iodide (I−) into the water sample. Oxidation of the iodide (I−) ion occurs due to the dissolved oxygen and the iodide (I−) turns to iodine. Titration is used to determine the amount of formed iodine; a standard thiosulfate (S2O3 -2) solution is used for titration. The amount of dissolved oxygen within the water is comparative to the titrated iodine and is calculated using the titer (McDonald, 2010). Change in water temperature Temperature of all obtained samples will be measured using thermometric procedure; measurement of temperature should be performed at the sampling site to avoid changes in temperature if the sample takes time prior to being measured. Extreme changes in water temperature have been associated with fish kill (Townsend et al, 1999). Increased water temperature is an indication of thermal pollution. Human activities such as industrial activities can discharge substances that result to sudden temperature changes of the water (Eric, 2014). Temperature affects the metabolism and growth of aquatic life. Oxygen solubility is also affected by increased temperatures. Additionally, evidence shows that changes in water temperature cause oxidative stress in aquatic animals (McDonald, 2010). Total Suspended Solids (TSS) Filter paper will be used to filter known amounts of water sample. The filtered solids should be dried and total suspended solids established. The significance of measuring the TSS is because suspended solids can cause water pollution if they are in high concentration and consequently adversely affect aquatic organisms (Howitt et al, 2007). Total dissolved solids (TDS) Total dissolved will be measured using Electrical Conductivity meter in order to examine the substances dissolved in the water (Howitt et al, 2007). PH The PH of all samples will be measured through potentiometric procedure Gas chromatography Gas chromatography will be used to identify possible various organic compounds within the water samples Discussion According to Kibria (2014) some causes of fish kill can be attributed to insufficient dissolve oxygen, extreme water temperatures, sudden changes in water temperature and discharge of toxic substances in the water. This is in line with Small et al (2014) who explain that low oxygen levels and water toxicity are some of the most common causes of fish kill. Some factors that cause low levels of oxygen in the water include: High water temperatures: levels of dissolved oxygen tend to decrease with the increase of water temperature and therefore it is important to measure temperature levels (McDonald, 2010). High levels of nitrogen: Excessive nitrogen can result to decreased DO. In the case study, excess nitrogen can be due to affluent that is discharged in the river from the sewage treatment plant. Extreme biochemical oxygen demand (BOD: Sediments and substances discharged in the river can absorb the available oxygen. According to Paerl et al (1999) this can result to a decrease in the available oxygen and cause hypoxic events which in turn can result to sudden death of the aquatic animals. Additionally, evidence shows that s light reduction and DO can result to death of aquatic life because of hypoxia (Paerl et al, 1999). This is because low levels of PH decrease the affinity of fish’s gills for oxygen and this directly impacts hypoxia tolerance. Reduced PH in the water samples will be an indication of high concentrations of dissolved organic substances or carbon dioxide (Small et al, 2014). Finally, in case the fish kill was due to methyl-mercury, mercury will be identified within the water samples. As Kibria (2014) indicates, fish kills incident is a pointer that ecosystems health and water quality have depreciated and therefore the water kill at the Styx River is an indication of depreciation of the river’s the ecosystem health and water quality. Conclusion Polluted and contaminated water has reduced levels of dissolved oxygen. This can be attributed to excess utilization of the available oxygen by the water contaminants. Waste materials discharged in the river from the sewage as well as the affluent from the brewery could be the main causes of reduced levels of dissolved oxygen. In addition, the water could have been contaminated by mercury from the ABChemicals that manufactures methyl-mercury. Basically, all these are potential causes of the fish kill that occurred at Styx River. Recommendations Ammonia and B.O.D analysis should be performed during the first day of sampling Calibration of all equipment used in assessments and analysis should be done to ensure their accuracy. The measurements should be performed during sampling Gas chromatography method is supposed to be utilised in determining the various organic substances within the water As a long term measure, surface water discharge into the river should be monitored carefully and examined regularly to identify any possible contaminants and pollutants (McDonald, 2010) It is also important to ensure that the effluent discharged into the river is irradiated using UV light in order to ensure any possible microbes in the river water are killed Physio-chemical parameters of the surface and ground water in the river should be examined regularly in order to ensure that they are within the acceptable limits (Heil et al, 2001). Reference list Allison M & Antonietta Q, 2010, Near-Annual Fish Kills in Small Embayments: Casual vs. Causal Factors, Journal of Coastal Research, 26(5): pp. 957 – 966. Eric M, 2014, Description of Conditions Preceding the 2011 Redondo Beach, California, Fish Kill, Journal of Coastal Research, 1(10), pp: 795-799.  Hewlett, J.R., Snow, J & Britton, J.R. 2009, The role of management practices in fish kills in recreational lake fisheries in England and Wales, Fisheries Management and Ecology, 1(16), pp: 248-254. Howitt, J.A., Baldwin, D.S., Rees, G & Williams, J.L, 2007, Modelling blackwater: Predicting water quality during flooding of lowland river forests, Ecological Modelling Hobbs, J-P.A. 1(1). Heil, C. A., Glibert, P. M., Al-Sarawl, M. A., Faraj, M., Behbehani, M., & Husain, M, 2001, First record of a fish-killing Gymnodiniumsp bloom in Kuwait Bay, Arabian Sea: chronology and potential causes, Marine Ecology-Progress Series, 214, 15. Haley N, 2016, Glastonbury Festival faces fine after pollution killed endangered fish: Pollution from a sewage container at the Glastonbury Festival has killed protected fish, The Telegraph. Kaur P, Aschner M & Tore S, 2011, Biochemical Factors Modulating Cellular Neurotoxicity of Methylmercury, Journal of Toxicology, 2011 (2011), pp: 1-9. Kibria G, 2014, Global fish Kills: Causes and Consequences, ResearchGate, DOI: 10.13140/RG.2.1.1422.8965. Lusk D, Rich E & Bristol R, 2005, Methylmercury and other Environmental Contaminants in Water and Fish Collected from Four Recreational Fishing Lakes on the Navajo Nation, 2004, U.S. Department of the Interior, Fish and Wildlife Service, or U.S. Geological Survey. McDonald, C.A. 2010, Increased seawater temperature and decreased dissolved oxygen trigger fish kill at the Cocos (Keeling) Islands, Indian Ocean, Journal of Fish Biology, 77, pp: 1219-1229. Paerl, H.W., J.L. Pinckney, J.M. Fear, and B.L. Peierls, 1999, Fish kills and bottomwater hypoxia in the Neuse River and Estuary: reply to Burkholder et al, Marine Ecology Progress Series, 186: 307-309. Small K, Kopf K, Watts R & Howitt J, 2014, Hypoxia, Blackwater and Fish Kills: Experimental Lethal Oxygen Thresholds in Juvenile Predatory Lowland River Fishes, PLoS One, 9(4): e94524. Townsend, S.A., Boland, K & Wrigley, T.J. 1992, Factors contributing to a fish kill in the Australian wet/dry tropics, Water Research, 26(8), pp: 1039-1044. Read More