Hazardous Chemicals Affect Living Things Unit C Chapter 3 Section 3

Biomagnification The increase in concentration of a chemical or element as it moves up the food chain Ex. Mercury: Bacteria change it into a molecule that can be absorbed by Algae (low concentration) Algae eaten by invertebrates like insects (have to eat lots = increase in Hg concentration) Insects eaten by fish (stored in body tissues; have to eat lots so Hg concentration increases) Humans eat fish

Mercury Mercury is a toxin affecting the brain: Shaking and slurred speech are symptoms of mercury poisoning. Did you know? In the 1800’s, hat-makers would use mercury to give wool a metallic shine. This is where the term mad as a hatter came from.

Exxon Valdez Oil Spill

Exxon Valdez Occurred in 1989 Vessel carrying crude oil from Alaska to the Western USA

Crude Oil Consists of a mixture of many chemicals Paraffin wax, asphalt, methane, nitrogen, oxygen, sulfur, mercury, lead, etc. Must be processed at a refinery Heated and the chemical compounds separate as the cool

The Spill Spilt 260,000 barrels of oil (41,000+m 3 ) Lighter molecules disperse and in air and water Heavier hydrocarbons (tar balls) washed ashore or sank as sediment Some bacteria were able to degrade the oil for food Some hydrocarbons are toxic at concentrations of 1ppb Oil can persist in environment for 10+ years Covered 1000+km 2 of of water and 100+km 2 of shoreline

Affects on Organisms Floating algae killed Invertebrates could not survive due to the decreases dissolved O 2, loss of food, and toxins

Affects on Organisms Fish eggs and young fish Pink salmon and Pacific herring fry dies or became deformed Adult fish were able to swim away from oil, but still suffered a loss of habitat

Affects on Organisms Seabirds and aquatic mammals were covered with oil Oil drenched fur and feathers cannot protect animals from the cold

Affects on People Large population of commercial fisherman Not able to do any fishing, and killed entire populations People who relied on wildlife for food had to begin to buy expensive groceries

Results 50% biodegraded/degraded by light in water 20% degraded by light in air 2% beached 14% recovered 1% dispersed in water 13% deposited in subtidal sediment

The Gulf Oil Spill 172 million gallons spilt compared to 10.8 in Alaska

The oil reservoir was tapped 5 486m below seafloor. B.P. expected to extract 50 million barrels (1 barrel = 159 L) The open reservoir leaked over barrels of oil per day creating an oil slick larger than South Carolina The leak was finally capped on July 15, 2010, nearly three months after the disaster. An estimated 725 million L of oil leaked into the Gulf of Mexico over the near 3 month period. Nearly 18x the volume of the Exxon Valdez.

The U.S. offshore oil industry includes roughly active oil rigs in the Gulf of Mexico and several smaller scale fields in Alaska and California.

Complete Check and Reflect on page 252. Questions 1, 4, 5, 6. Due tomorrow before class. Complete Unit Review P.268 #2,3,5,7-12,14,18