The Investigation of an Environmental Disaster Involving a Mass Fish Kill Event on River Styx - Case Study Example

The Investigation of an Environmental Disaster Involving a Mass Fish Kill Event on River Styx Name Tutor Course Institution Date The Investigation of an Environmental Disaster Involving a Mass Fish Kill Event on River Styx Background A massive fish kill event was reported to the department of Fisheries on 22nd march 2017 by the local members who live next to the river. Wild fish kill incidences have been on the rise globally. River Styx has experiences fish kills in the past but not to this magnitude as has been reported now. There are approximately 2000 tons of fish that were found dead on the said day. According to Neilson and Johnson (2003) many fish kill incidences are always occurs in inland water and are triggered by a myriad of factors which could either be man-made or natural. In a study conducted by Richardson (1998) the number of fish sometimes is small like 30 or 50 but in some very unfortunate cases it may be up to thousands of tons . For instance it was estimated that a total number of 29000 tons of fish died of some strange disease between the years 1998 and 1999. Available literature shows that in many cases fish kills happen as a result of the following factors; diseases, low dissolved oxygen, contaminations for example by pesticides or herbicides, involvement of harmful algae, harsh environmental conditions, physical irritants among others (Phillips 1999). In general fish kill investigation are very challenging exercises that are normally hindered by various factors some which are logistical, legal, environmental factors and the surrounding community apathy(Pattiaratchi, 2016). The common logistical challenge that investigators face is inaccessibility to the site of the fish kill. River Styx is located in a rather hilly terrain and the very point where the fish died doesn’t have good access roads. When investigators cannot adequately reach the site of the fish kill it means that the results may be biased as they may not be able to collect certain key data. This is so especially in determining the exact number of fish that really died. When fish kills occur it is important to conduct a proper and timely diagnosis so as to determine the exact cause. This information is very important for aquaculture, recreational and wild capture fisheries, those intrusted in environmental issues the government and the general public (Helleren, 2016). Attaining the requisite information for the Styx river fish kill was important in detecting any deadly diseases in a reasonable to support the surveillances and monitoring both at the national and international level. This is so especially since in many cases many fish kill incidences have been linked to poisoning. This then requires an emergence intervention so that the necessary legal action can be undertaken based on sound forensic information. To determine whether a fish kill investigation should be undertaken is a procedure which (Calow, 1993) summarises as follows; The purpose of this investigation is to design an experimental and sampling procedure that was to specifically identify the cause of the fish in river Styx and thereafter provide a long term sampling program to prevent future occurrences. Methods The investigation was based on the methods that are provided by the American Fisheries Society (1992). Usually it is very challenging to sample dead fish because for reliable data to be obtained then necessary trained personnel and equipment should be available (American Fisheries Society, 1993). This investigation various samples were collected to be analysed so as to determine the exact cause of the fish kill. The samples included; water, toxicity, fish and sediments. The investigators ensured that the water samples collected are representative of the surrounding conditions. The investigators employed two strategies in the collection of water sample; depth-and –width-integrated samples and collecting grab samples. The toxicity samples were subjected to microtox tests whereby water was analysed to determine the presents of any toxins. The fish samples were collected so as to enable the investigators to search for disease causing pathogens, perform autopsy as well as carry out tissue analysis. The sediments samples were collected to help in determining the presence of toxic substances that may have existed in the river for a very long time and cannot be dictated through water analysis Environmental Protection Agency, 2000).The samples were then subjected to toxicity test to determine the effects of any possible toxins on the fish and other biological methods so as to determine the level of present contaminants. In this investigation the following procedure was utilised; Receipt of the Fish kills notification Collection of background data Survey of river Styx and collection of relevant samples, evidence and photos Reporting about the on-site survey Analysis of the collected samples Interoperation of samples and presentation of findings Follow-ups Debriefs This can be diagrammatically presented as follows; Results and Findings Low Oxygen Conditions The investigators were interested in finding out whether the collected samples. This is because river Styx is located in an area that is characterised by low levels of dissolved oxygen. The area is relatively low and highly sheltered which means that there are few chances of water exchanges. The water analysis did find that the river Styx had high levels of dissolved oxygen Disease as a possible cause The results proved that disease was not the cause of the fish kill. This is because scholars have indicated that when disease is the cause of the fish kill usually a specific species is affected (Mclnich and Garman, 1998). However this is not the case here because all the types of fish and even other living animals in the river were affected. Presence of Harmful Algae From the results provided in the table below it was evident that indeed the river had some worrying levels of harmful algae. The algae present here were linked to the way the deaths were happening. They would begin in the morning until evening then subside till the next morning. According to Meyer and Barclay (1990) algae results in fish kills especially when a certain species dominates the environment and starts to compete for nutrients with the other species which in this case is the river. What happens is that as the competition intensifies, the level of toxins released also increases. As time goes by the other species die because of lack of nutrients. The most dominant species continues to produce more toxins as it competes against itself until the water becomes too toxic for other living organisms in the water which may include fish, insects and even animals that come for drinking water in the river (Newman Piavaux and Sweeting, 1992). The tests results showed that the pH of the water was very high ranging at 9.9 to 11.0 especially during the day. This is the point where oxygen is usually at the point of saturation and water temperatures are reading 27 degree Celsius and above. The Styx River was found to be dominant with the following species of algae microcytis, glenodinium and gleotrichia. Environmental Conditions The investigators received support from the meteorological department so as to find out whether environmental factors were at play in the fish kill that occurred at Styx. It was found out the temperature levels at the time of the fish kill were a little more high compared to many months before. The investigation team also analysed the tide and weather conditions. The weather conditions were found to be relatively normal given the time of the year, however the team also realised that the volume of deoxygenated was also relatively high. Presence of Physical irritation The investigators carried out histopathological examination of some of the fish tissues such as the gill and it was evident that indeed there were signs of irritation such as hyperplasia, congestion and inflammation. In a study conducted by Jenkins and Barhead (1993) when this happens, it’s an indication that the water is of poor quality or it’s the evidence for an external irritant which then affect the respiratory ability of the fish. Presence of Contaminants The water and sediment samples that were collected were tested for the presence of any of the following contaminants; heavy metals, organic fertilisers, herbicides, pesticides, nitrogen and shellfish toxins (Helleren, 2016). The results proved that there was no significant presence of these contaminants in the river that could have caused the fish kill in Styx Conclusion and Recommendations From the analysis above it is apparent that the fish kill in Styx was not as result of manmade toxic or diseases. The causes are out of natural environmental issues relating to whether conditions and the presence of harmful algae. The weather related disturbances like the high temperatures are the ones that triggered the fish kill. The investigation results suggested that the unusual hot weather that hasn’t been the case at this time of the year coupled with the toxic algal blooms provoked the massive fish kill in the river. The other factor that led to the fish kill was found to be the natural toxic substances that caused physical irritation in the fish tissues. The low level dissolved oxygen levels led to respiratory difficulties in the fish. Therefore in conclusion the cause of this specific fish kill is basically natural causes. Therefore there is need to put in place intervention strategies to stop future or further deaths of the fish in other rivers in the country. Putting in mind that it’s the responsibility to come up with programs on the safety and maintenance of natural resources like water, it is important to call upon the various key stakeholders to come up with strategies that will help eliminate the toxic algae that are infesting the river. The government needs to work hand in hand with researchers so as to conduct further researches on the presence of the algae so as to determine the best remedy for that. Additionally the changing climatic conditions while generally may be blamed on climate change; needs to be investigated further keeping in mind the social, cultural and economic conditions of the surrounding area and its people. The public needs to be educated on how they can be part of this noble cause. They need to understand how they can be agents of climate change as well as how they can be change agents so as to restore the glory of Styx River. In summary the intervention strategy will have to be consultative and participatory in nature so as to include academicians, the government, environmentalists, fishermen, non-governmental organisations and the general public. List of References American Fisheries Society. 1992, Investigation and Valuation of Fish Kills. American Fisheries Society Special Publication 24. Bethesda, Maryland. American Fisheries Society, 1993, Sourcebook for Investigation and Valuation of Fish Kills. American Fisheries Society Special Publication 24. Bethesda, Maryland. Barbour, Michael T., Jeroen Gerritsen, Blain D. Snyder, James B. Stribling, 1999, Rapid Bioassessment Protocols for Use in Wadeable Streams and Rivers, EPA Stock Number 841-B-99-002. United States Environmental Protection Agency, Office of Water 4503F, Washington, DC Calow, P. 1993, Handbook of Ecotoxicology. Blackwell Scientific Publications, Oxford. Environment Protection Agency, 2000, Guidance for Assessing Chemical Contaminant Data For Use in Fish Advisories, EPA Stock Number 823-B-00-007, Office of Water, Washington DC 20460. Helleren, S. 2016, The diatom Chaetoceros spp. as a potential contributing factor to fish mortality events in Cockburn Sound, November 2015. Dalcon Environmental Jenkins, R.E., & Burkhead, N. M. 1993, Freshwater Fishes of Virginia. American Fisheries Society, Bethesda, Maryland. McIninch, P. & G.C. Garman. 1998, A Field Identification Key to the Freshwater Fishes of Virginia-Draft. Virginia Commonwealth University, Richmond, Virginia. Meyer, F. P., & Lee A. Barclay, editors, 1990, Field Manual for the Investigation of Fish Kills. U.S. Fish and Wildlife Serv, Resour. Publ. 177. 120 pp. Mason, C.F. 1991, Biology of Freshwater Pollution. Longman, Harlow (Second edition, 1999). Newman, P.J., Piavaux, M.A. & Sweeting, R.A. 1992, River Water Quality - Ecological Assessment and Control. Commission of the European Communities, Brussels. Nielson, L.A., and D.L. Johnson. 2003. Fisheries Techniques. American Fisheries Society. Bethesda, Maryland. Philips, D. J. H. 1999, Quantitative Aquatic Biological Indicators. Applied Science Publishers Ltd, London. Richardson, M. 1998, Ecotoxicology Monitoring. VCH Verlagsgesellschaft, Weinheim Pattiaratchi, C. 2016, Oceanographic conditions along the Perth Metropolitan region leading to the observed fish kill event in Cockburn Sound, November 2015. University of Western Australia. Read More