Unit 8 Human Impacts on Aquatic Ecosystems (APES 24 - 25)

Front

Which of the following water cycle processes are connected to surface water on Earth? I. groundwater infiltration II. surface water runoff III. evaporation

Back

I, II, and III

Answer explanation

All three processes are connected to surface water. Groundwater infiltration affects surface water levels, surface water runoff directly involves surface water, and evaporation occurs from surface water bodies.

Front

Which of the following is a non-point source of water pollution? Effluent from a sewage treatment plant. BP refinery in Indiana discharging ammonia into a river. Runoff of pesticides from regional farms into the Illinois River. Hot water discharges from a nuclear power plant.

Back

Runoff of pesticides from regional farms into the Illinois River.

Answer explanation

Runoff of pesticides from farms is a non-point source because it comes from multiple, diffuse sources rather than a single, identifiable outlet like a sewage treatment plant or refinery.

Front

Which of the following is a probable impact of increased use of inorganic (lab-made) fertilizers in a watershed? Hypoxia in the Gulf of Mexico, Increase in storm severity in southeastern U.S., Water shortages in California, Saltwater intrusion on the East Coast.

Back

Hypoxia in the Gulf of Mexico

Answer explanation

Increased use of inorganic fertilizers can lead to nutrient runoff into waterways, causing algal blooms. When these blooms die, they deplete oxygen in the water, resulting in hypoxia, particularly in areas like the Gulf of Mexico.

Front

What are the health risks associated with eating some fish from lakes or the ocean?

Back

If they are high on the food chain, they may contain high levels of mercury or PCBs.

Answer explanation

Fish high on the food chain can accumulate harmful substances like mercury and PCBs, posing significant health risks to those who consume them. This makes the correct answer crucial for understanding the dangers of eating certain fish.

Front

If a paper mill dumps a lot of paper (organic) waste into a nearby river, all of the following are likely to happen EXCEPT: Increase in BOD, Decrease in DO, Algae growth, Decrease in decomposers

Back

Decrease in decomposers

Answer explanation

The decrease in decomposers is unlikely because organic waste typically provides food for them. In contrast, BOD increases, DO decreases, and algae growth occurs due to nutrient enrichment from the waste.

Front

What is it called when a persistent pollutant (like mercury or PCBs) builds up in the tissues of an organism as they continue to eat something that contains the pollutant?

Back

Bioaccumulation

Answer explanation

The process where persistent pollutants like mercury accumulate in an organism's tissues as they consume contaminated food is called bioaccumulation. This differs from biomagnification, which refers to the increase in concentration up the food chain.

Front

Strategies used to clean up oil spills include all of the following EXCEPT:
- Floating booms and boats to skim floating oil towards collectors
- Skimmers to absorb oil from the water
- Chemical dispersants that break up the oil and help it to sink.

Back

Addition of limestone to neutralize the oil

Answer explanation

The addition of limestone is not a recognized method for cleaning oil spills. Instead, techniques like skimming, using skimmers, and chemical dispersants are effective in managing oil on water.

Front

What is the main source of mercury in the Great Lakes?

Back

Coal-burning power plants

Answer explanation

The main source of mercury in the Great Lakes is coal-burning power plants, which release mercury into the atmosphere. This mercury can then deposit into the lakes, contributing significantly to contamination.

Front

The pollution of waterways creates conditions in which productivity is decreased and the gills of bottom-dwelling organisms are clogged. This is due to:

Back

Erosion and sedimentation

Answer explanation

Erosion and sedimentation lead to increased sediment in waterways, which clogs the gills of bottom-dwelling organisms and reduces productivity. This makes it the correct choice for the pollution effects described.

Front

What do we call the land area that supplies water to a river system?

Back

Watershed

Answer explanation

The land area that supplies water to a river system is called a watershed. It collects precipitation and directs it to rivers, making it crucial for water flow and ecosystem health.