aquatic pollution

point source

distinct location where pollution is from

ex. smoke stack, waste discharge, pipe

nonpoint source

diffuse area that produces pollution

ex. farming region, urban storm runoff

water pollution

contamination of streams, rivers, lakes, oceans, groundwater, from human activities

wastewater

water produced by livestock operations/human activities

-human sewage from toilets

-gray water from bathing/washing of clothes/dishes

wastewater problems

1. nutrient release

2. oxygen demand

3. disease-causing organisms

eutrophication

phenomenon in which a body of water becomes rich in nutrients

part of 1. nutrient release

cultural eutrophication

increase in fertility in body of water bc of anthropogenic nutrients from agricultural runoff and wastewater.

biochemical oxygen demand

BOD - amt of oxygen quantity of water uses over period of time

low BOD = body water is less polluted

eutrophication steps

1. excessive nutrients enter water body - FERTILIZERS

2. algal bloom occurs due to excessive nutrients

3. algae covers water prevents sunlight from penetrating water

4. vegetation dies due to lack of sunlight

5. decomposers (microbes) use O2 to break down vegetation

6. dissolved oxygen (DO) decreases

7. fish die to lack of O2

oxygen demand

decomposers need O2 to break down organic matter

low O2 level = highly polluted = high BOD

dead zone

area with extremely low oxygen concentration and little life

range of tolerance

ideal range of abiotic conditions/temperature organisms can survive, grow, and reproduce

oxygen sag curve

shows changes when organic waste is added to aquatic ecosystem

DO decreases bc of increased BOD → shift in biodiversity

gulf of mexico dead zone

mississippi river receives water from 41% of us land - contains wastewater and fertilizer → algal blooms → dead zones

raw sewage and detergents are dumped into water → dead zone

solutions to gulf of mexico dead zone

1. reduce nitrogen fertilizer in midwest farms

2. change timing of fertilizer use to minimize runoff during rainy season

3. plant alternative crops

4. manage nitrogen-rich livestock manure more effectively

5. construct artificial wetlands to filter farm runoff

6. improve sewage treatment

7. restore frequently flooded lands to reduce runoff

8. restore wetlands near mississippi river’s mouth to improve nitrogen-absorbing ability

disease causing organisms

wastewater contains pathogens - can be contracted by coming into contact with contaminated water

cholera, typhoid fever, stomach flu, diarrhea, hepatitis etc.

indicator species

species that indicates if disease-causing organisms are present

ex. fecal coliform bacteria

fecal coliform bacteria

generally harmless microorganisms in human intestines

E.coli - detected in drinking water → drinking water has been contaminated with wastewater

septic system

small and simple sewage system - septic tank, leach field

RURAL AREAS

septic tank

large container that receives wastewater from house as part of septic system

sludge

solid waste material from wastewater and sinks to bottom

needs to be pumped 5-10 years

septage

layer of clear water in middle of septic tank

large quantities of bacteria - breakdown organic material into CO2 and nitrogen/phosphorous

may contain pathogens

leach field

component of septic system - underground pipes laid out below surface of ground

through gravity - septage moves from septic tank to pipes in leach field

septage slowly is absorbed/filtered by surrounding soil

sewage treatment plant

municipalities (MUD) use centralized sewage treatment plant

primary treatment

physical removal of large objects through use of screens and grates

solid waste settles at bottom of tank

secondary treatment

biological process in which bacteria break down organic matter into carbon dioxide and inorganic sludge

settles at bottom of tank

aerated to increase rate bacteria breaks down organic matter

tertiary treatment

removes pollutants like nitrogen and phosphorous

treated water

also exposed to disinfectants - chlorine, ozone, UV light to kill bacteria

CAFO manure

problem bc of volume - hormones and anitobiotics that are given to animals

spread onto fields as fertilizer

manure lagoon

human made pond lined with rubber to handle large amounts of manure from CAFO

endocrine disrupter

chemical that interferes with normal functioning of hormones in animal body

lead to birth defect, developmental disorders, gender imbalances in fish/other species

hormones

regulate functioning of body - growth, metabolism, development of reproductive organs

hormone-disrupting chemicals

mimic hormones in body, bind to receptive cells, cause cell to respond in ways not beneficial to organism

reproductive hormone

endocrine disrupter

found in wastewater - feedlots, birth control pills, pesticides

fish, reptiles, amphibians are affected

lead

found in pipes/other materials in older construction

nervous system damage, reduced IQ, attention problems, kidney damage

declined in US since banned lead gasoline, paint, pipes, solder

flint river

high in chlorides concentrations - corrosive to lead pipes

lead leached into city’s water supply

arsenic

occurs naturally/human activity - mining/industry

cancers of skin, kidneys, lungs, liver

mostly upper midwest and west of US

mercury

occurs naturally/human activity - burning coal, garbage, hazardous waste, medical/dental supplies

wetland/lakes- bacteria convert inorganic mercury → methylmercury = highly toxic to humans

damages central nervous system in young children/developing embryos of women

• exposed through eating fish - raw fish is bad

most in asia - bc industrialization

oil pollution

petroleum products- highly toxic to marine organisms - birds,mammals, fish, algae, microorganisms

drilling for oil using offshore platforms, spills from oil tankers

natural seeps

oil spills

cause organisms to die from hydrocarbons in oil

coats feathers of birds/mammals

kills bottom-dwelling organisms

economic consequences on fishing/tourism industries

boom

keeps oil from spreading, boats with oil vacuums suck up oil

oil pollution containment

1. booms

2. chemicals break up oil on surface - disperse before hits shoreline

3. bacteria consume oil - scientists try to genetically engineer to make it faster

non-chemical water pollution

1. solid waste/trash/litter

2. sediment

3. thermal

4. noise

litter/trash pollution

creates intestinal blockage/choking hazards for wildlife

introduce toxic substances to food chain

great pacific garbage patch

large area of solid waste- composed of microplastics floating on north pacific

sediment pollution

soil particles carried downstream

30% of sediment in waterways from natural sources

70% human activities

sediment pollution problems

• suspension of soil particles cause waterways to become brown/cloudy

• reduced infiltration of sunlight - lowers productivity of aquatic plants/algae + vision of predators

• clogs gills/prevent oxygen

• disrupt habitats

• collects in reservoirs bc dams block it from moving downstream

thermal pollution

nonchemical water pollution occurs when humans cause change in water temp

industry uses cold water to absorb heat in manufacturing process → returns back to natural supply

ex. water used to cool power plants discharged into surface water

thermal shock

dramatic change in water temp that kills organisms

high water temp

increases respiration rates in species and decreases DO - organisms suffocate

thermal pollution solution

pump water into holding ponds so water can cool before its released back into natural bodies of water

cooling towers release excess heat into atmosphere instead of water

noise pollution

sounds from ships, submarines, interfere with animal communication

loud sonar negatively affects whales - rely on low freq, long distance comm

persistent organic pollutants

persistence of chemical refers to length of time chemical remains in environment

toxic to organisms bc they’re fat soluable - accumulate in organisms’ fatty tissues

POPs

travel long distances over wind and water before redeposit

persistence

depends on several factors including temperature, pH, if chemical is in water/soil, degraded by sunlight/microbes

measured in half-lifes

POPs

synthetic carbon based molecule with long half-life + break down slowly

ex. DDT and PCB

bioaccumulation

increased concentration of chemical in organism over time

biomagnetification

increase in chemical concentration in animal tissues as chemical moves up food chain

can cause issues with human reproductive, nervous, circulatory system

eggshell thinning, developmental deformities in top carnivors of higher trophic levels

wetlands

areas where water covers soil, part/full time

wetland ecological services

water purification, flood protection, water filtration, habitat

wetland threats

wetland + mangrove :

commercial development

dam construction

overfishing

pollutants from agricultural and industrial waste