Sources of Fresh Water & Marine Pollution (DP IB Environmental Systems & Societies (ESS))

Pollution caused by excessive organic matter such as untreated human sewage, animal waste, or decaying plant material

Excessive organic material can lead to oxygen depletion, harmful algal blooms, and eutrophication in water bodies

Pollution from excess nitrates and phosphates primarily originating from agricultural runoff, sewage, and fertilisers

Elevated levels of these nutrients can cause nutrient enrichment, leading to algal overgrowth and water quality degradation

Pollution caused by heavy metals such as mercury, lead and arsenic, often originating from industrial activities, mining, or improper waste disposal

These metals can accumulate in aquatic organisms, leading to toxic effects and posing risks to human health and ecosystems

Pollution resulting from human-made chemicals, including pesticides, herbicides, pharmaceuticals, and industrial pollutants

These compounds can enter water bodies through runoff, discharges, or improper disposal, potentially harming aquatic life and human health

Pollution caused by the presence of solid particles in water, typically sediment, silt, or fine particles from erosion, construction, or dredging activities

High concentrations of suspended solids can impair water clarity, clog fish gills, smother benthic habitats, and impact aquatic organisms such as invertebrates and their larvae

Pollution from the release of heated water into aquatic systems, often associated with industrial processes or power generation

Elevated water temperatures can disrupt aquatic ecosystems, reduce oxygen levels, and negatively impact fish and other organisms (e.g. disrupting migration patterns or natural breeding cycles)

Pollution resulting from oil spills, leaks, or discharges from shipping, oil exploration, or industrial activities

Oil can coat the water surface, affecting marine and freshwater ecosystems, harming aquatic life such as seabirds, and leading to long-term environmental damage

Pollution caused by the release of radioactive substances, often associated with nuclear accidents, mining, or waste disposal

Radioactive pollution can have severe ecological and human health impacts, with prolonged exposure potentially leading to genetic mutations and cancer

Pollution from the presence of disease-causing microorganisms, including bacteria, viruses, and parasites, often originating from sewage or animal waste

Pathogens can contaminate water sources, leading to waterborne diseases (such as cholera) and posing risks to human and animal health

Pollution resulting from excessive artificial lighting, particularly in coastal areas

Light pollution can disrupt natural light cycles, affecting nocturnal marine species and disrupting reproduction, navigation, and feeding patterns of marine organisms

Pollution caused by anthropogenic noise from activities such as shipping, sonar, construction, or offshore energy production

Excessive noise can disrupt communication, feeding, and migration patterns of marine species (such as whales), leading to ecological disturbances

Pollution resulting from the introduction of non-native species into aquatic ecosystems, often through ballast water or occasionally intentional release (e.g. for biological control or recreational fishing purposes)

Invasive species can outcompete native species, alter habitat structure, disrupt food webs, and cause severe ecological imbalances (e.g. the invasion of lionfish into U.S. Atlantic coastal waters)