Unit 8 APES- 8.2, 8.4, 8.5, 8.6 Human Impacts on Ecosystems, -- Wetlands & Mangroves, Eutrophication, Thermal Pollution

Pollutants cause physiological stress such as:

limited growth, limited reprod. function, difficulty respiring (breathing), potential asphyxiation (suffocation), hormonal disruption, death

Env. Effects of Acid Rain- pH Tolerance

As pH decreases out of optimal range, pop. decline /

As pH leaves range of tolerance, species die due to: aluminum toxicity, disrupted blood osmolarity

Indicator species can be surveyed & used to...

determine conditions of an ecosystem (soil, water, etc.)

Temp. Tolerance of Reef Algae

algae have narrow temp. tolerance and leave reef when temp. rises-> coral reef become stressed & vulnerable w/o algae (food source)

Oil Spill Effects

hydrocarbons in crude oil toxic to marine organisms and kill them / oil can wash ashore & decrease tourism revenue & kill fish, decrease fishing industry revenue, hurt restaurants that serve fish

How do oil spills occur?

underwater oil well explodes/blows out or a tanker runs into a rock/iceberg and is punctured

Oil Spill Clean-up

booms on surface to contain spread; ships w/vacuums or devices to skim; physical removal from sand and rocks w/towels, soaps, shovels; burning surface oil off;

Threats to Wetlands

pollutants: nutrients (N/P), sediment, motor oil, pesticides, endocrine disruptors

development: wetlands filled in or drained & developed into homes, parking lots, stores, agricultural land

water diversion upstream for flood control

dam construction for flood

overfishing

Decomposition=

aerobic process

Major N/P Sources

*discharge from sewage treatment plants

*animal waste from CAFOS

*synthetic fertilizers

Oligotrophic Waterways

waterways w/low nutrient (N/P) levels, stable algae pop., & high dissolved oxygen

Ponds naturally shift from...

oligotrophic to mesotrophic to eutrophic

What causes a dead zone?

decrease in dissolved oxygen (hypoxia)

Warmer water temperature = decreased ___________ ___________

dissolved oxygen

Thermal Pollution

heat released into water having neg. effects on organisms living in water

*increases respiration rate of aquatic organisms (thermal shock) which could cause suffocation

Sources of Thermal Pollution

power plants, steel/paper mills, manufacturing plants use cool water to cool down machines & return warmed water;

urban stormwater runoff w/heat from blacktop/asphalt

Cooling Towers/ponds

cool steam back into water & hold warmed before returning to local surface water