A factory smokestack and a sewage overflow

Runoff from city streets and pesticides from agricultural fields

Waste from animal feedlots and sediment from construction sites

Fertilizer from suburban lawns and wastewater from a water treatment plant

A factory smokestack and a sewage overflow

Runoff from city streets and pesticides from agricultural fields

Waste from animal feedlots and sediment from construction sites

Fertilizer from suburban lawns and wastewater from a water treatment plant

Decreased oxygen levels in surface water as a result of a decrease in photosynthetic rates by algae

Increased oxygen levels in bottom water from increased rates of cellular respiration in decomposers

Decreased oxygen production by seaweed on the seafloor from an increase in turbidity

Increased oxygen production by decomposition of dead fish and other aquatic organisms

Bacteria and viruses

pesticides

herbicides

phosphates

acid wastes

The released water is radioactive and is lethal to a variety of organisms in the reservoir.

Chemical pollutants in the released water cause algal blooms in the reservoir.

Ash from the power plant is dissolved in the released water and will precipitate out into the reservoir.

The temperature of the released water causes a decrease in the amount of dissolved oxygen in the reservoir.

POPs accumulate in the body fat of living organisms. POPs  increase in concentration as they move up the food chain.

POPs can travel over long distances by wind or water. Predators have greater access to different locations than do producers and therefore have higher concentrations of POPs.

POPs are not carbon-based compounds, so animal digestive systems lack enzymes capable of breaking them down.  POPs biomagnify in the fatty tissues of animals but not in plants.

POPs are solids, which only animals can ingest. Therefore, POPs have a greater effect on secondary and tertiary levels of food chains.

decomposers

primary consumers

parasites

secondary consumers

autotrophs

A

B

C

D

Regulating the use of pesticides and fertilizers in agriculture

Preserving wetland and coastal mangrove habitats

Increasing the capacity of the sewer lines so they can handle a larger volume of water

Straightening stream channels to increase stream flow

A series of screens and grates to prevent large objects from entering the landfill

A bottom liner of plastic or clay to prevent groundwater contamination

Aerated tanks in which bacteria break down organic matter

Chemical or ultraviolet light systems that kill pathogens