THE EFFECT OF POLLUTION ON MARINE LIFE

Thesis Overview

1.0 INTRODUCTIONThe importance of water for sustenance of life cannot be overemphasized. Be it for microorganisms, plants, plankton, aquatic animals, benthos and the entire marine life or for man, it’s importance remain immeasurable. It is therefore, important to note that depletion of this natural resource either through contamination, or careless use results in serious consequence.Man’s activities sometimes, bring about undesirable changes in the physical, biological and chemical characteristics of the natural environment. This is termed pollution. It may be harmful to human or non-human life. This may affect the soil, rivers, the atmosphere, or the seas (causing harm to marine life).Marine life is a vast resource, providing food, medicine, and raw materials, in addition to helping to support recreation and tourism all over the world. At a fundamental level, marine life helps determine the very nature of our planet. Many species are economically important to humans including both finfish and shellfish. Large areas beneath the ocean surface still remain unexplored (Nybakken and Bertness, 2005).The marine environment supplies many kinds of habitats that support marine life. Marine life depends in some way on the saltwater that is in the sea (Dickinson, 1963). It is an ecosystem which includes a host of organisms ranging from tiny planktons to large whales. Marine habitats can be divided into pelagic (found near the surface or in the open water column, away from the bottom of the ocean) and demersal (near or on the bottom of the ocean) habitats. (Nybakken and Bertness, 2005).Some marine organisms, like corals, kelp, mangroves and sea grasses are ecosystem engineers which reshape the marine environment to the point where they create further habitat for other organisms. Specific habitats include coral reefs, kelp forests, sea grass meadows, muddy, sandy, and rocky bottoms, and the open ocean (pelagic) zone (Kritzer and Sale, 2006).1.1 WHAT IS POLLUTIONPollution is the process of making land, water, air or other parts of the environment dirty and unsafe or unsuitable to use. This can be done through the introduction of a contaminant into a natural environment, but the contaminant doesn’t need to be tangible. Things as simple as light, sound and temperature can be considered pollutants when introduced artificially into an environment (Alina, 2015).Pollution could be in different forms, includingAir pollution which is the release of chemicals and particulates into the atmosphere.Light pollution: the impact that man- originated light has on the visibility of the night sky.Noise pollution: This encompasses aircraft noise, roadway noise, industrial noise as well as high-intensity sonar (used to locate objects underwater).Thermal pollution: is a temperature change in natural water bodies caused by human influence (such as use of water as coolant in power plant).Plastic pollution: involves the accumulation of plastic products in the environment.Visual pollution: this could refer to the presence of overhead power lines, motorway billboards, open storage of trash or space debris.Water pollution: discharge of wastewater, untreated domestic sewage, and other contaminants (intentionally or through spills) into water bodies.1.2 WHAT ARE POLLUTANTSPollutants are simply defined as the substances which cause pollution. A pollutant is any substance or energy produced and released into the environment as a result of human activities that has damaging effects on living organisms. Pollutants may cause long- or short- term damage by changing the growth rate of plant or animal species.Some pollutants are biodegradable (e.g. sewage) that is, can be rendered harmless by natural processes, and therefore will not persist in the environment in the long term if adequately dispersed or treated. Others are non-degradable (e.g. heavy metals such as lead), which means that they eventually accumulate in the environment and may be concentrated in food chains, having long term effects (Tietenberg, 2006).Notable pollutants include the following groups;Heavy metals like leadPersistent organic pollutants (POP)Environmental persistent pharmaceutical pollutants (EPPP)Volatile organic compounds Environmental xenobiotics. (Tietenberg, 2006)