Pollution of Lakes and Rivers

Chapter 1:There is no substitute for water

Copyright © 2008 by DBS

Contents

• Our water planet• Water and Aquatic Ecosystems• Major Properties of Water• Horizontal Zonation• The Hydrologic Cycle• Water: a Scarce Resource• Human Influences on Water Quality• Ecosystem Approaches to Water Management• Pollution• This Book

There is No Substitute for WaterOur Water Planet

• 75 % of Earth’s surface• Only small portion is accessible• Importance

– 70 % human body– Required for human food supply– Habitat for more than ½ world’s

species of plants and animals

Natural WatersThe Blue Marble

75 % surface > 1 x 109 km3

The Blue Marble is a famous photograph of the Earth taken on 7 December 1972 by the crew of the Apollo 17 spacecraft at a distance of about 29,000 km or about 18,000 miles. It is one of the most widely distributed photographic images in existence. The image is one of the few to show a fully lit Earth, as the astronauts had the Sun behind them when they took the image. To the astronauts, Earth had the appearance of a child's glass marble (hence the name).

There is No Substitute for WaterOur Water Planet

• Limnology – study of inland waters

There is No Substitute for WaterOur Water Planet

• Paleolimnology – study of preserved properties (physical, chemical, biological) to reconstruct past conditions

There is No Substitute for WaterWater and Aquatic Ecosystems

• Unlike other substances water is less dense in solid form than liquid form

• Water at different temperatures has different densities – leads to layering in lakes

Becoming less dense

• Water shrinks on melting (ice floats on water)

• Unusually high melting point• Unusually high boiling point• Unusually high surface tension• Unusually high viscosity• Unusually high heat of vaporization• Unusually high specific heat

capacity• And more…

There is No Substitute for WaterBox 1.1 Major Properties of Water

Due to H-bonds

http://www.lsbu.ac.uk/water/anmlies.html

There is No Substitute for WaterBox 1.1 Major Properties of Water

There is No Substitute for WaterWater and Aquatic Ecosystems

• Dimitic lakes – mix twice during spring and fall, stratified in summer

• Monomictic lakes – mix once during the cold season (more common in sub-tropical regions)

– Epilimnion – upper– Metalimnion or thermocline– Hypolimnion – deep and cold

There is No Substitute for WaterHorizontal Zonation

periphyton – organisms attached to substratesepiphyton – organisms attached to plantsepilithon – organisms attached to rocksepipsammon – organisms attached to sand grainsepipelon – organisms living in the sediments

plankton, e.g. algaezooplankton, e.g. water fleesnekton, e.g. fishneuston – organisms living at the air-water interfacebenthos – organisms living in the sediments

Littoral zone – where rooted plants grow (macrophytes)

Pelagic region – open-water region

There is No Substitute for WaterBox 1.3 The Hydrologic Cycle

Source: http://www.nasa.gov/vision/earth/environment/warm_wetworld.html

Compartments• Atmosphere• Land• Groundwater• Rivers lakes• Oceans

Precipitation that fall directly onto the lake Precipitation that fall directly onto the catchment

Precipitation

There is No Substitute for WaterWater: a Scarce Resource

• How much of the Earth’s water is available to humans for drinking, agriculture and industry?

SourcesWhere Does Potable (fit for consumption) Drinking Water Come From?

Surface water: from lakes, rivers, reservoirs (< 0.01 % of total)Ground water: pumped from wells drilled into underground aquifers (0.3 %)

Less than one third of salt-free water is liquid

There is No Substitute for WaterHuman Influences on Water Quality

• Our short visit to planet Earth has been very influential

• 10,000 yrs B.P. development of technological civilizations

• Growing populations

• Ecological footprint of modernman is far greater

• Has lead to water stress

• Quantity of available water will stay the same

• Quality will decline

There is No Substitute for WaterJournal Articles

Either:

Postel, S. and Carpenter, S. (1997) Freshwater ecosystem services. In Daily, G.C. (ed), Nature’s Services. Island Press, Washington, D.C., pp. 195-214.

Or:Ricciardi, A. and Rasmussen, J. (1999) Extinction rates of North American freshwater fauna. Conservation Biology, Vol. 13, pp. 1220-1222.

There is No Substitute for WaterEcosystem Approaches to Water Management

• Freshwater systems are linked to their catchments (watersheds) as well as the atmosphere above them

• Research must consider all environments and the pathways between them

There is No Substitute for WaterPollution

• May be chemical, biological or physical

• Point and non-point sources

There is No Substitute for WaterThis Book

• About the effects humans have had on aquatic ecosystems

• Methods we may use to study these effects

There is No Substitute for WaterSummary

• Water covers 75 % Earth’s surface

• ~ 95 % salty

• Fresh water stored in glaciers and polar ice

• ~ 0.01 % in freshwater lakes and rivers

• Volume does not change, quality does

• Pollution and degradation increased with population

• Many researchers believe we are approaching a world water crisis

References

• Ball, P. (1999) Life’s Matrix: A Biography of Water. Farrar Straus & Giroux, New York.

• Kalff, J. (2001) Limnology. Prentice Hall, Upper Saddle River, NJ.• Likens, G.E. (ed.) (1985) An Ecosystem Approach to Aquatic Ecology: Mirror

Lake and Its Environment. Springer-Verlag, New York.• Naiman, R.J., Magnuson, J.J., McKnight, D.M. and Stanford, J.A. (eds.) (1995)

The Freshwater Imperative: A Research Agenda. Island Press, Washington, D.C.• Postel, S. and Carpenter, S. (1997) Freshwater ecosystem services. In Daily,

G.C. (ed), Nature’s Services. Island Press, Washington, D.C., pp. 195-214.• Ricciardi, A. and Rasmussen, J. (1999) Extinction rates of North American

freshwater fauna. Conservation Biology, Vol. 13, pp. 1220-1222.• Smol, J.P. (1990) Are we building enough bridges between paleolimnology and

aquatic ecology? Hydrobiologia, Vol. 214, pp. 201-206.• Spiedel, D.H. and Agnew, A.F. (eds.) (1998) Perspectives on Water: Uses and

Abuses. Oxford University Press, New York.• Wetzel, R.G. (2001) Limnology: Lake and River Ecosystems. Academic Press,

San Diego.