8.2: Human Impacts on Ecosystems

What are factors that contribute to an organism’s range of tolerance?

pH, temperature, salinity, sunlight, nutrient levels

What is a range of tolerance

An organism’s tolerance to its natural abiotc conditions in its environment, as well as human pollution

What are some of the ways that Pollution can cause physiological stress?

Limited growth, limited reproductive function, difficulty breathing, hormonal disruption death

What is a big theme in Unit 8 about pollutants?

Specific effects of pollutants on organisms

What happens to populations as pH decreases?

Populations decrease

Why can’t organisms survive in low pH levels?

Aluminum toxicity, Disrupted blood osmolarity

What are Indicator Species?

Can be surveyed and used to determine conditions of an ecosystem

What do high whitemoss/filamentous algae populations indicate?

pH greater than 6

What does high crustacean populations indicate?

pH lower than 6

What is a Coral Reef?

muutualistic relationship between coral and photosynthetic algae called zooxanthellae

How is the range of tolerance for zooxanthellae like?

It has a narrow range of tolerance

What happens when the conditions are out of the range of tolerance for Zooxanthellae?

They leave the reef

What can drive algae out of corals?

pesiticides, pollutants, pH changes, temp. changes

What happens to the corals once the algae leave?

They lose their color and become vunerable to disease

How do humans impact coral reefs?

Via greenhouse gas emissions

How can fishing damage coral reefs?

Decreased fish population and bottom trawling for fishing can break reef structure and stir up sediment

How can sediment pollution be harmful?

Makes water more turbid, decreasing photosynthesis

How can Toxicants be harmful?

Can kill algae of corals

What are some pollutants from humans that can be harmful for corals?

sediment, toxicants, nutrients from farms and CAFOs

How can oil spills be harmful?

Oil is toxic to many aquatic organisms and can be especially deadly if ingested

How can oil spills be harmful besides being deadly?

Decreases visibility and photosyntheis; Oil sticks to bird feathers, preventing them from flying; Oil kills ocean floor organisms

How can oil spills impact the economy?

Decreased tourism revenue; decreased fishing industry revenue; decreased revenue for fish restaurants

How can oil spills impact estuary habitats?

Can kill root systems in mangrove and salt marshes, and can also remove the habitats and breeding grounds of fish and shellfish

How does an oil spill occur?

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

How are Oil spills cleaned up?

Vacumns to clean up oil, physical removal from beaches, Chemicals to break up oil, burning oil off of surface

How can oil be physically removed?

It can be physically removed via towels, soaps, or shovels

How can chemicals that are used to clean up oil spills be harmful?

Can smother bottom-dwellers, and some of the chemicals can be harmful