Aquatic Ecosystems Quiz

What is the average salinity of the oceans?

• 20 ppt

• 35 ppt

• 50 ppt

• 10 ppt

What is the depth where no sunlight penetrates and photosynthesis cannot occur called?

• Benthic zone

• Aphotic zone

• Photic zone

• Euphotic zone

Where do most aquatic consumers obtain the oxygen they need to carry out cellular respiration from?

• Air

• Soil

• Water taken in through gills

• Sunlight

What causes warmer temperatures in the upper layers of aquatic ecosystems?

• Presence of sunlight

• Seasonal temperature changes

• Shifting currents

• Depth of the water

What type of aquatic ecosystem contains water that is in near-constant motion?

• River

• Wetland

• Pond

• Lake

What is the measurement of salinity in parts per thousand (ppt)?

• 1000 units of salt dissolved in 1000 units of water

• 500 units of salt dissolved in 1000 units of water

• 100 units of salt dissolved in 1000 units of water

• 50 units of salt dissolved in 1000 units of water

What is the uppermost layer of an aquatic ecosystem, where there is enough sunlight for photosynthesis, called?

• Benthic zone

• Aphotic zone

• Euphotic zone

• Photic zone

What is the range of salinity for water to be considered 'fresh'?

• 0.5 - 30 ppt

• 30 - 50 ppt

• 70 - 100 ppt

• 50 - 70 ppt