Which of the following are freshwater ecosystems?
Answers: ponds, lake, river

produces most of the food in the ocean.
Answers: Phytoplankton

Freshwater wetlands include and
Answers: marshes and swamps
is a measure of the amount of salt dissolved in water
Answers: salinity

Which biome is pictured above?
Answer: coral reef

is an excessive richness of nutrients in a lake or other body of water, frequently due to runoff from the land, which causes a dense growth of plant life and death of animal life from lack of oxygen.
Answers: Eutrophication

Sunlight cannot penetrate deeper layers of the ocean so cannot happen.
Answers: photosynthesis

Most marine organisms live in
Answer choices:
A. shallow coastal waters
B. fisheries
C. deep ocean water


Data analysis
Aquatic Organism pH Range for Life
Clam 4.5 - 5.0
Snail 5.0 - 9.0
Bass 5.5 - 9.0
Crayfish 5.5 - 8.5
Mayfly 5.5 - 9.0
Salamander 6.0 - 8.0
Trout 6.0 - 8.5
Perch 6.5 - 8.5
Frog 7.0 - 9.5
To test acidity levels of water, scientists test the pH. As acid rain falls, the pH levels in lakes and streams decrease. While certain animals can tolerate low pH levels, others are extremely sensitive to the effects of acid rain and cannot live under the conditions. Once the pH of the pond drops below 5.5, we can expect which aquatic life form(s) to die out?
Answer choices:
A. trout and salamanders
B. clams and snails
C. perch