Question

1. what causes most coastal pollution in the united states? mark only one oval.

a. lakes and ponds
b. industrial waste and sewage
c. over fishing
d. temperature changes

1. most pollutants that enter estuaries break down over time, yet they are still considered a problem because mark only one oval.

a. the pollutants eventually enter the ocean.
b. it is the volume of the pollutants, more than the time factor, that harms estuaries.
c. the pollutants break down into still more dangerous toxins.
d. none of the above

1. what distinguishes nekton from benthos? mark only one oval.

a. one lives in a freshwater ecosystem and the other lives in salty water.
b. one swims freely and the other often lives attached to a hard surface.
c. one is a predator and the other is a primary producer.
d. none of the above

1. wetlands perform several important environmental functions. which do you think is most crucial? defend your answer.

1. give one example of how coral reefs are threatened by human activities and one example of how estuaries are threatened by human activities.

Explanation:

1. Industrial waste and sewage are major sources of coastal pollution in the US as they introduce harmful chemicals, heavy - metals, and pathogens. Lakes and ponds are not a cause of coastal pollution, over - fishing is a problem for marine life but not a major pollutant source, and temperature changes are more related to climate change rather than direct pollution.
2. The volume of pollutants entering estuaries is a significant problem even if they break down over time because large amounts can overwhelm the ecosystem's ability to cope. While pollutants may eventually enter the ocean, it's the initial impact on estuaries that matters most here. And not all pollutants break down into more dangerous toxins.
3. Nekton are organisms that swim freely in the water column, while benthos often live attached to a hard surface on the bottom. They are not distinguished by freshwater/saltwater habitats, nor by being predators or primary producers.

Answer:

1. B. Industrial waste and sewage
2. B. It is the volume of the pollutants, more than the time factor, that harms estuaries.
3. B. One swims freely and the other often lives attached to a hard surface.