U.S Clean Water Act
Return all U.S surface waters to fishable or swimmable conditions
Water Pollution Def
Any physcial, biological, or chemical change in water quality that adversely affects living organisms or makes water unsuitable for desired uses
discharged pollution from specific locations (factories, power plants, drain pipes)
Scattered or diffuse, having no specific location of discharge (agricultural fields, feedlots
contaminants carried by air currents and precipitated into watersheds or directly onto surface waters as rain, snow, or dry particles. Can also evaporate from lakes.
Main source of waterborne pathogens is improperly treated human waste. Also run off from animal feedlots
Intestinal bacteria, used to detect water contamination, generally disinfected via chlorination
4 billion cases per year worldwide. 2.2 million deaths. 50 % of hospital beds are occupied due to water borne diseases
What is the desirable oxygen content for aquatic life
oxygen content under 2 ppm
supports mainly decomposes
how is oxygen added to water
by diffusion from wind and waves and by photosynthesis from green plants and algea
Biochemical Oxygen Demand
amount of dissolved oxygen consumed by aquatic microorganisms.
oxygen levels decline downstream from a pollution sources as decomposes metabolize waste materials
bodies of water that have clear water and low biological productivity
bodies of water that are rich in organisms and organic material
process of increasing nutrient levels and biological productivity
increase in biological productivity and ecosystem succession caused by human activities
when does an Algea bloom occur
bloom occurs when a single microbial species, algal or cyanobacterial, grows at expense of other members of community
inorganic pollutants (metal)
mercury, lead, cadmium, and nickel are highly toxic. Highly persistent and tend to bioaccumulate in food chains
How does metal get in the water?
mine drainage and leaching are serious sources of environmental contamination
why is mining a problem?
it decreases groundwater depth and natural filtration
inorganic pollutants (salts)
many salts that are non-toxic at low concentrations can be mobilized by irrigation and concentrated by evaporation, reaching levels toxic to plants and animals. (leaching off road salts)
thousands of organic chemicals are used to make pesticides, plastics and pharmaceuticals. Improper disposal of industrial and household wastes and runoff of pesticides from fields, roadsides, and gold courses is problematic.
"polychlorinated Biphenyls" man mad and causes skin effects, liver damage, and reproductive damage
Human activities have accelerated erosion rates. It obstructs shipping channels, clogs hydroelectric turbines, smothers fish eggs, and block out light needed for photosynthesis
raising or lowering water temps from normal levels can effect water quality and aquatic life. Oxygen solubility decreases as temperatures increase.
Industrial cooling processes often uses heat exchangers to extract excess heat and then discharge it back into the water. Heat sensitive organisms die and other ones that are attracted to heat die when the plant shuts down.
considered impervious to pollution and half of us population gets water from underground aquifers
Ground water is hard to monitor
1.2 trillion gallons of contaminated water seep into the groundwater every day. comes from septic tanks, cesspools, and landfills
fixing underground water contamination
easier to prevent then treat. Protect water sources and aquifer recharge zones. Install modern technology for monitoring, consolidate small systems
coastal zones often are overwhelmed by contamination from heavy metals, toxic chemicals, oil, and sediment. 3-6 million tons of oil are released into oceans each year.
Human waste disposal
in many areas, outdoor urination is ok but it is a problem in big cities. In asia, fertilizer is spread on fields but it can cause diseases
Municipal sewage treatment
primary treatment- physical separation of large solids from waste and stream. Secondary treatment- biological degradation of dissolved organic compounds. Tertiary treatment- removal of plant nutrients from secondary
low-cost waste treatment (wetlands)
effluent flows through wetlands where it is filtered and cleaned b aquatic plants and microscopic organisms
how much solid waste is produced annually
11 billion tons. 50% agricultural waste, 33% from mining. Industrial waste and municipal waste.
release hazardous materials. still predominant method of waste disposal in developing countries.
nearly uncontrollable. Nearly 20 million tons of plastic are dumped at sea a year. eaten by wildlife or washed up onto beaches
great pacific garbage patch
floating garbage is now collecting in the center of the north pacific gyre. it is a circular collection of ocean currents
export of waste
industrialized nations have agreed to stop shipping hazardous and toxic waste to less-developed countries. 80% of electronic waste is shipped abroad, mostly to asia and africa
refuse compacted and covered everyday with a layer of dirt. now all landfills in the US are required to have lining and drainage systems. One positive thing is methane recovery.
heat derived from incinerated refuse is a useful resources - steam used for heating buildings or generating electricity. Expensive. High levels of toxins in ash...need to remove heavy metals before burning
reprocessing of discarded materials into new and useful products. aluminum cans, old tires, newspapers, copper.
disassembly and recycling of obsolete appliances and electronics. In europe, manufactures have a "cradle to grave" responsibility for their products.
how much hazardous waste is produced
1 ton per person per year
where does our hazardous waste come from
metal processing and mining, chemical and petroleum industries.
a hazardous waste site that is part of the EPA super fund program. Total cost for cleanup is expensive. Most sites are old industrial facilities and chemical manufacturing plants. mining areas also prime source of toxic waste.
waste management options
produce less waste- recycle and reuse. Convert to less hazardous substances - physical treatment, incineration, chemical processing. Store permanently- in containers in salt mines or caverns.
measures variety of different versions of same genes within a species
mmeasures numbe rof different kinds of organisms within a community
measures richness and complexity of a community
total number of species in a community
relative abundance of individuals within each species
organisms that breed in nature and produce fertile offspring
phylogenetic species concept
emphasizes the cladistic relationships
evolutionary species concept
defines a species in terms of evolutionary history.
how many species are there?
1.6 million identified. Estimated 2-50 million. Invertebrates most undiscovered species.
tropical rainforests and coral reefs
food benefits of biodiversity
wild plants could provide new sources of food or more genetic diversity for existing crops
drug and medicine benefits of biodiversity
more than half of all prescription contain some natural product.
ecological benefits of biodiversity
soil formation, waste disposal, air and water purification, and solar energy absorption all depend on biodiversity. we don't fully understand effects.
elimination of a species
natural causes of extinction
one species per decade. humans have accelerated it to hundreds or thousands
extinction in fossils
fossil records suggest that 99% of species ever in existence are now exctinct.
acceleration of extinction rate
humans accelerate it 100-1000x. If present rates continue, half of all primates and one quarter of all bird species will go extinct in 50 years.
Habitat destruction, invasive species, pollution, population, over harvesting
biggest cause of extinction
exotic organisms thrive in new territory where they are free of usual predators, disease, or resource limitations that limited them in original habitat.
island ecosystems are particularly susceptible to biodiversity loss. New Zealand has lost 40% of its native flora and fauna