Which layer is at the bottom of freshwater?

Which layer is at the top of freshwater?

________________ is less than 1% salt

An animal found in the midnight zone.

Oceanic Zone means "no bottom".

Oil leaking down a storm drain.

Water pollution that comes from excess phosphorus and nitrogen.

Water pollution that comes from human waste.

A wetland surrounded by land.

A wetland that is mossy and spongey.

Clean our water for free!

Clean our air for free!

Clean Water Act was signed by

Ozone is made of _________ oxygen molecules.

Toxins moving up the food chain.

A water plant.

The ozone belongs in the _________________, but when it is found in the troposphere it is called ______________.

Which leads to acid rain?

The president who is known for setting aside many national parks.

The first national park?