ES 6.3-4

The distribution of many aquatic organisms is determined largely by

• the temperature of the water

• the depth of the water

• the salinity of the water

• the clarity of the water

The warm, nutrient-rich, shallow water of the ocean over the continental shelf that contains 90% of all marine species is

• the abyssal zone

• the coastal zone

• the floodplain

• the watershed

Estuaries are coastal wetland ecosystems that are found

• where rivers empty into the sea

• in higher elevations where they are fed by melting snow

• in the euphotic zone of the ocean

• near inland wetlands

Brackish water is usually found

• in oligotrophic lakes

• in eutrophic lakes

• in the open ocean

• in estuaries

In which aquatic life zone would you expect to find coral reefs?

• Wetlands

• Transition zone

• Coastal zone

• Bathyal zone

The middle zone of the open sea, known as the bathyal zone, is

• dimly lit and does not contain photosynthesizing producers

• dark and cold and contains little dissolved oxygen

• brightly lit by sunlight and contains phytoplankton

• has crystal clear water and very steep sides

Phytoplankton, found in the the euphotic zone of the open ocean, produce about percent of the world's oxygen through photosynthesis.

• 10

• 25
• 40

• 80

In which ocean zone would you expect to find bioluminescent organisms like the angler fish?

• Euphotic zone

• Bathyal zone

• Coastal zone

• Abyssal zone

The burning of fossil fuels

• A. prevents ocean acidification because it increases the amount of carbon dioxide in the atmosphere

• B. contributes to ocean acidification because it increases the amount of carbon dioxide in the atmosphere

• C. reduces the amount of sunlight that reaches the abyssal zone

• D. contributes to the acidification of the inland wetlands

Which of these ecosystems are most affected by ocean acidification?

• coral reefs

• coastal marshes

• shorelines

• mangrove forests