Term
| how much water is out there? |
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Definition
•71% of earth’s surface covered with water.
•99% in ocean depressions (avg. depth 3,800 m)
•0.009% in freshwater lakes
•0.00009% in rivers
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Term
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Definition
•Exponential human growth and utilization of freshwater.
•BUT: consumption increases in response to rising supply.
•Environmental Problems:
population growth + technological growth
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Term
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Definition
production:use and degradation of environments
consumption: comsuming technological products which leads to pollution of water sources
We surpass the amount of water that would correspond to us:
1.Personal requirements /person
2.Industrial water demand /person
3.Agricultural water demand /person
we use water from: •1/3 of rain reaches oceans as river discharge
•2/3 of rain evaporates + plant transpiration
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Term
| Physical Characteristics of the Great Lakes |
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Definition
•Water content: 23,000 km3 (5,500 cu. mi.).
•Area covered: 244,000 Km2 (94,000 sq. mi.)
•Largest system of fresh surface water in the world, GL contain 18% of world supply of freshwater.
•One other lake contains about the same amount….which one?
•Polar ice caps contain more freshwater than the GL.
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Term
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Definition
–Runoff from soils and farm chemicals
–Waste water from cities
–Discharge from industrial areas
–Leachate from solid waste disposal sites
–Direct atmospheric pollutants (dry, rain or snow) due to their large size.
Outflows from the GL are relatively small: less than 1% per year,
•Pollutants accumulate in the system and become more concentrated.
•Pollutants are resuspended by mixing.
•Pollutants cycle through biological food webs.
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Term
The carcinogenic effects of toxic pollutants
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Definition
Fish consumption provides the greatest potential for exposure of humans to toxic substances found in the Great Lakes.
For example, a person who eats one meal of lake trout from Lake Michigan will be exposed to more PCBs in one meal than in a lifetime of drinking water from the lake.
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Term
| chemical pollution in great lakes |
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Definition
Many of the chemical pollutants discharged in the Great Lakes can mimic hormonal activity:
• Development
• Sexual differentiation
Metabolism
Chemicals with hormonal activity include, among others:
•Halogenated aromatic compounds such as PCBs and PBDEs
•Synthetic estrogens
•Natural estrogens
Sources:
• Runoff into streams (urban, industrial, agricultural)
• Storm sewers
• Waste water treatment plants’ discharge
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Term
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Definition
•Specific 'at-risk' groups of concern include:
–Native peoples,
–Anglers and their families,
–Immigrant groups who rely on fish and wildlife for a large part of their diet.
•Epidemiological studies of Michigan residents have demonstrated that people who regularly eat fish with high levels of PCBs have much higher concentrations in their bodies than others.
•There is also concern about antagonistic and synergistic interactions between toxic substances.
Exposure to low levels of some contaminants may cause effects on reproduction, development and other physiological parameters.
Effects may go easily unnoticed in the short term, but in the long term may lead to serious cumulative damage.
New studies show effect of persistent contaminants on:
•The immune system.
•The nervous system.
•Pre-natal and post-natal development.
•Fertility.
•Development of cancers.
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Term
Histology Lake Erie Steelhead Trout
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Definition
Sby a resting stage marked by apoptosis and the loss of pawning is followed lumen in the tubule.
Signs of dysfunction:
No evidence of recent spawning: not a single sperm cell can be found.
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The tubules in male steelhead trout exhibit prominent lumina.
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Term
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Definition
•Isotopes are atoms of the same element that differ in atomic mass, due to differences in the number of neutrons contained in the atoms' nuclei.
•Example:
– 12C (6 neutrons, stable)
– 13C (7 neutrons, stable)
– 14C (8 neutrons, unstable)
•Stable isotopes are measured by gas isotope-ratio mass spectroscopy.
•The sample is converted into a gas (CO2, N2)
•The gas molecules are ionized in the Ion Source
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Term
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Definition
•standard is defined as 0‰.
•For Carbon, the international standard is Pee Dee Belemnite, a carbonate formation.
•The Pee Dee Belemnite absolute ratio of 13C/12C is 0.0112372.
•Materials with ratios of 13C/12C > 0.00112372 have positive delta values
•Those with ratios of 13C/12C < 0.00112372 have negative delta values.
•For Nitrogen, the international standard is the Nitrogen content of air.
•The Nitrogen in Air absolute ratio of 15N/14N is 0.003676.
•Materials with ratios > 0.003676 have positive values.
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Term
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Definition
•Some progress, some signs of recovery, but pollution will continue to be a major concern in the years to come.
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•A broader scope of regulation of toxic chemicals may be necessary as research and monitoring reveal practices that are harmful.
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•More stringent controls of waste disposal are already being applied in many locations.
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•Agricultural practices are being examined because of the far-reaching effects of pesticides and fertilizers.
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Term
| People in Great lakes ecosystem |
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Definition
•As people living around the lakes make the connection between themselves and the Great Lakes, they will become increasingly involved in positive actions.
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•People are reclaiming, cleaning up and restoring their watersheds, local shorelines, parks and green space.
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•Through careful management of technology and economic development, people can live within the ecosystem without causing injury.
In return, the lakes and the lands surrounding them will continue to contribute to the quality of life for the people of the region and all living things in the Great Lakes ecosystem and beyond.
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