Water Ecosystems

WATERSHED

• defined as a geographic area of land in which precipitation drains to a common point on a stream, river, pond, lake or other body of water such as wetlands.

WETLAND

• any land area such as a bog or marsh, that is covered in water a large part of the year and support specific plant species. (bogs, fens, marshes and swamps)

HUMAN IMPACT on FRESHWATER ECOSYSTEMS

• All urban, rural and industrial land uses can potentially affect or be affected by surface and groundwater quality and quantity in a watershed.

Eutrophication• process by which surrounding watershed enriches

bodies of water with nutrients that stimulate excessive plant growth, especially algae.

• excessive algae growth not only absorbs the oxygen from the other plants and animals in the watershed but it creates a blanket on the surface of the water blocking sunlight to the organisms underneath.

Water Pollution• the leading

worldwide cause of deaths and diseases

• it accounts for the deaths of more than 14,000 people daily.

• there are acute problems of water pollution in third world countries.

Point Source Water Pollutants:• Sewage discharge• Factory waste from pipes• Dumping of toxic waste in barrels• Trash and waste into storm drains that empty

into nearby watersheds• Oil Spills• Animal Waste from agriculture • Construction sites

Non-Point Source Water Pollutants

• Runoff –rain water carrying fertilizers, road salt, leakage from vehicles (oil, antifreeze, windshield fluid)

• Chemicals from washing cars in driveways

• Household chemicals• Trash

Human Impacts on Water Resources

• 75% of our planet is covered with water BUT less than 1% is suitable for human use.

• •About 70% of the water withdrawn each is year is used to irrigate 18% of the world’s croplands.

• •About 23% of freshwater is used for cooling purposes in power plants, for oil and gas production.

• •About 7% is used for domestic and municipal uses around the world.

• •In the US , about 23% of all freshwater is pumped from aquifers (water filled rocks layers found underground )

Water Pollution• Precipitation can

absorb pollutants, such as sulfur dioxide from burning of fossil fuels, creating acid rain which can destroy trees vegetation and ancient structures/statues.

•Burning of fossil fuels and manufacturing also releases mercury (ingested by fish). •Bioaccumulation of the mercury levels is causing increased disease in higher ocean predators such as bears, large cat species, large birds of prey and even humans.

Ocean Pollution

• Sources of Ocean Pollution• 44% is Runoff from the land (trash and chemicals

run off roadways into storms drains). • Storms drains River Ocean• 33% Airborne pollution• 12% shipping and spills• 10% Ocean Dumping• 1% off shore mining

Carbon Sink and Coral Bleaching

• Carbon Sink is the absorption of CO2 from the air into the water. (increased acidity in oceans)

• Coral Bleaching is caused by warming of the oceans (coral will reject algae causing their death)

• Coral Reefs are the most productive ecosystem of the world!

• 25% have been destroyed, 60% are threatened, and predicted to be gone in 50 years.

Cruise Ships

• Grey water refers to waste water that has been tainted by soaps, detergents, and other sources of negative environmental impact but does not include human waste.

• •Cruise ships dump 200,000 gallons of raw sewage and at least 35,000 gallons of other wastes weekly!

Trash in our oceans

• 80% of all trash in the ocean is plastic.• •These products are eaten by wildlife, cause

suffocation and cause animals to be entangled and injured. Many animals choke to death, die of starvation or infection from the plastic “flotsam”.

• •The Giant Pacific Garbage Patch is roughly the size of Texas and up to 90 feet deep!

• •The Atlantic Garbage Patch’s length is equivalent to the distance from D.C. to the edge to Florida.

Documentary

Oil Spills• causes starvation in seabirds, hypothermia in sea

otters and sea mammals, blindness in cretaceans as well as blood poisoning in large sea mammals such as killer whales

• •Exxon Valdez in 1989 dumped 11 million off the coast Alaska

• •Recent Spills of 2010:• –Gulf of Mexico oil rig explosion was leaking 210,000

gallons a day. (4.9 million barrels total = 205.8 million gallons)

• –Chinese freighter into Great Barrier Reef, released 65,000 of coal and fuel oil

Some of the Worst Oil Spills

1. Kuwait, 1991 252 mill gallons2. Mexico, 1979-1980, 140 mill gallons3. Trinidad and Tobago 1979, 90 mill gallons4. Uzbekistan, 1994, 84 mill gallons5. Persian Gulf, 1983, 80 mill gallon Gulf

• What Does 184 Million Gallons of Oil Look Like?