Pollution can take many forms (e.g. water, air, soil) and have diverse and devastating impacts on individuals and the environment. Some of these impacts are difficult to ascertain. For example, it will not be known for many years what the actual extent of the BP Oil Spill in the Gulf of Mexico in 2010 will have on marine and bird life that are dependent on the surrounding environment.
Land pollution is the general degradation of the land surfaces, usually due to human activities and the misuse of resources. The most severe type of land pollution is land contamination.
The effects of land pollution for humans, plants and animals can include health issues such as deformities and cancer.
Air pollution is the accumulation of substances in the atmosphere at such concentrations that can endanger health or negatively impact living organisms.
The major air pollutants are carbon monoxide, hydrocarbons, nitrogen oxide, sulphur dioxide, particulates and photochemical oxidants.
Water pollution is an issue in both our rivers and in the ocean. There are many causes of water pollution including introduction of effluent, heavy metals, agricultural fertilisers high in nutrients such as nitrates and phosphates and siltation.
Eutrophication is defined as the process by which a body of water acquires a high concentration of nutrients. This is becoming a large problem in marine environments due to the excessive amounts of organic matter entering waterways. These are sourced from sewage, livestock, agricultural fertilisers, soil eroding from deforestation and upwelling of deep ocean waters. Eutrophication is particularly harmful to coral reefs. As corals have evolved in the lowest nutrient environments in the world, small increases in nutrients can then rapidly increase algal growth which in turn smothers and kills the coral underneath.
Pollution and degradation of marine and coastal environments is mainly caused by land-based activities. The main pollution pressures are derived from human settlement, population growth and urbanisation along coastal areas.
Sea Grasses and Coral Reef habitats are important breeding and foraging habitats for aquatic creatures. These habitats are being degraded by the dumping of dredge wastes and discharge of silt from adjacent coastal rivers. These are reducing the amount of light available to seagrass and coral therefore limiting their ability to grow.