IntroductionEnvironmental problems are commonly caused by anthropogenic activities that release toxins into the water bodies as well as the atmosphere, causing the loss of species and environmental hazards such as droughts and flooding. However, such environmental disasters occur when the capacity of the environment to absorb such pollutants is exceeded. Apart from observing the environmental problems that occur in any given area such as flooding, species extinction and drought, environmental analysis involves an investigation of the principal causes of such events and proposing recommendations to ensure that such events do not recur (Petrisier, 2014, p.
4, Morrison and Murphy, 2006, p. 7). The study explores the underlying causes of an environmental problem involving mass fish kills in River Styx approximately five miles from Styxton village. Fish kills refer to the death of fish species confined to a given area and usually linked with the death of other aquatic organisms. The causes of fish kills in an aquatic ecosystem are many and varied, with the most common one being oxygen depletion, specifically the reduced concentration of dissolved oxygen, which the fish depend on for survival (Govorushko, 2012, p.
60). Reduced concentration of dissolved oxygen in the water is caused by drought which causes an increase in the water temperature, algal blooms that compete with the aquatic organisms in the water for the dissolved oxygen as well as overpopulation in the aquatic environment (Goel, 2006, p. 3 and Jain, 2009, p. 76). The other causes of fish kills in a river include; diseases and parasites and toxicity to a lesser degree. The main reason why mass fish kills is considered as an environmental disaster is because the fish are keystone species and thus are indicators of environmental stresses.
It is, therefore, important for the environmental agencies to determine the causes of fish kills as soon as they occur to enable them establish the causes of such kills and prevent their repeated occurrences. Generally, many fish species have very low tolerance to variations that occur in the aquatic ecosystems. The death of such species is an indicator of the possible environmental problems that adversely affect other species within the aquatic ecosystem as well as the other uses of the water such as drinking.
Depending on the causes, fish kills can either be selective or general. Fish kills in the Styx River Fish kills in the Styx River can be linked with the presence of the Riverside Breweries, Styxton Sewage Plant and AB Chemicals at close proximity to the river thus releasing toxic waste, directly into the river contributing to the larger percentage of pollutant in the river. The manufacture of real ales by the Riverside Breweries involves a number of processes such as malting, milling, extract separation, hop addition and boiling, removal of hops and precipitates, cooling and aeration, fermentation, separation of yeast from young beer, aging, maturation and packaging.
All these processes result in the release of brewery effluent which is channelled into the river. Brewery effluent also contains such phosphates resulting from the detergents used in cleaning. The high temperature brewing process also contribute to thermal pollution.