WATER POLLUTION Environmental impacts Environmental Impacts Eutrophication Deoxygenation

WATER POLLUTION Environmental impacts

Environmental Impacts • • • Eutrophication Deoxygenation Coral reef destruction; Fish kills; Public health issues.

Eutrophication • Eutrophication is characterized by excessive plant and algal growth due to the increased availability of one or more limiting growth factors needed for photosynthesis such as sunlight, carbon dioxide, and nutrient fertilizers.

The Process of Cultural Eutrophication

Deoxygenation of Aquatic Systems • Biochemical oxygen demand (BOD) is a measure of the quantity of oxygen used by microorganisms (e. g. , aerobic bacteria) in the oxidation of organic matter. • Natural sources of organic matter include plant decay and leaf fall. However, plant growth and decay may be unnaturally accelerated when nutrients and sunlight are overly abundant due to human influence. E. g. Urban runoff carries pet wastes from streets and sidewalks; nutrients from lawn fertilizers; leaves, grass clippings, and paper from residential areas, which increase oxygen demand. • Oxygen (dissolved in the water, DO- Dissolved Oxygen) consumed in the decomposition process robs other aquatic organisms of the oxygen they need to live. (Deoxygenation)

Dissolved oxygen (DO) is a measure of the oxygen in the water. The removal of oxygen( deoxygenation) from an aquatic system can occur due to: q. Natural decomposition of organic matter measured by the BOD Deoxygenati on of Aquatic Systems q. Temperature (higher temperatures means less oxygen dissolved in the water. ) q. Chemical (nutrients) dissolved in the water; Organic overload. q. Pollution; agricultural waste, sewage, industrial runoff.

Coral Reef Destruction Coral reefs are important for many different reasons which include • Maintaining Biodiversity; containing the most diverse ecosystems on the planet. • Protecting coastlines from the damaging effects of wave action and tropical storms. • Provide habitats and shelter for many marine organisms. • See Clip “What Are Coral Reefs And What's Their Purpose? ” https: //www. youtube. com/watch? v=e. Iul 2 Obv. KV 8

Coral Reef Destruction; How Pollution Affects Coral Reefs Land-based pollution sources stem mainly from increasing runoff from land. v. Runoff often carries large quantities of sediment from land-clearing, v. High levels of nutrients from agricultural areas and sewage outflows, and v Pollutants such as petroleum products and pesticides. These land-based sources of pollution threaten coral reef health.

Excess nutrients result v In poor water quality, leading to decreased oxygen and increased nutrients in the water (eutrophication) v This can lead to enhanced algal growth on reefs, crowding out corals and significantly degrading the ecosystem. In addition, sediment deposited onto reefs v smothers corals and interferes with their ability to feed and reproduce. Finally, pesticides v interfere with coral reproduction and growth. Sewage discharge and runoff v can also introduce pathogens into coral reef ecosystems. E. g. Aspergillus sydowii has been associated with a disease in sea fans, and Serratia marcescens, has been linked to white pox, another coral disease.

Fish kills