APES Ch 14: Water Pollutants

sections 1-3

sediment

• soil particles in bodies of water

• 70% comes from human activities

• caused by clear cutting, mining, and clearing land for development increasing erosion rates

• physical pollutant

Issues with sediment

• blocks sunlight penetration reducing algae and plant productivity and predator visibility

• clogs gills + prevents aquatic organisms from obtaining oxygen

• physical pollutant

Solid waste

• garbage thrown away by people

  • litter the reaches aquatic ecosystems (unsightly, creates intestinal blockage, choking hazards, introduces toxic substances to the food chain)

• garbage dumping in the ocean was curtailed in the early 1980s, still an issue in developing countries

• physical pollutant

Thermal Pollution

• when human activities cause a large change in water temperature

  • a dramatic change can cause thermal shock, being fatal to organisms

  • warm water holds less oxygen

• ex. using river water as coolant for factories/power plants, deforestation near water reducing shade

• physical pollutant

Noise Pollution

• sounds emitted by ships and submarines can interfere with animal communication

• especially sonar - can negatively affect species such as whales that rely on low-frequency, long distance communication

• possible solution: engineering ships with quieter propellers

• physical pollutant

Synthetic compounds

• chemical pollutant

• can enter water from industrial plant sources or nonpoint sources when applied over large area

  • ex. pesticides, pharmaceuticals

• can be toxic, persistent, cause genetic defects, interfere with growth/sexual development

Oil

• chemical pollutant

• petroleum products are highly toxic to marine species

  • eg. birds, mammals, fish, algae, microorganisms at the base of the aquatic food chain

sources of oil pollution

• drilling for undersea oil on offshore platforms (deepwater horizon)

• oil spills

• natural oil seeps

remediation of oil

• containment: booms keep the floating oil from spreading for boat to vacuums to collect as much as possible

• dispersants: chemicals break up the oil on the surface so it can dissolve before reaching the shore

• bacteria: scientists trying to optimize oil-eating bacteria (bioremediation)

heavy metals

neurotoxins that affect nervous system functions or development

• lead: found it pipes/other materials in older construction

• arsenic: natural occurrence as well as human activity (mining, industry)

• mercury: natural occurrence and burning coal

biological pathogens

pathogenic microorganisms

pathogenic microorganisms

bacteria and protus, originating primarily from human and animal waste

manure and concentrated animal feeding operations (CAFOS) may contain pathogens such as _____ and _____

hormones and antibiotics used on animals

manure lagoons

ponds lined with rubber, used to store and decompose manure w/ bacteria for fertilizer

waste from humans and livestock in water effects on oxygen demand

more organic material = more microbes = higher oxygen demand

biological oxygen demand (BOD)

amount of oxygen a body of water uses over a period of time and specific temperatures

eutrophication/cultural eutrophication

an increase in the fertility of a body of water due to excess nutrients (nitrogen and phosphorus)

• cultural: an increase in fertility due to excess nutrients from human inputs (fertilizer/wastewater)

dead zones

an area with low oxygen concentration and little life

DO and BOD

always inverses

clean zone,

High DO, low BOD

decomposition zone

lower DO, higher BOD

septic zone

low DO, high BOD

recovery zone

rising DO, decreasing BOD

point sources

you can point to the place, discreet ex. abandoned mines, oil tankers

nonpoint sources

widely distributed areas ex. farms, roads, neighborhoods, fertilizer/pesticide runoff