What type of aquatic environment forms when freshwater mixes with saltwater?
Brackish water
What process changes liquid water into water vapor?
Evaporation
What process brings cold, nutrient-rich deep ocean water toward the surface?
Upwelling
What percentage of energy typically transfers from one trophic level to the next?
10%
Question: Is dissolved oxygen a biotic or abiotic factor?
Abiotic
An organism lives in water with a salinity of 35 ppt. Is its environment freshwater, brackish, or marine?
Marine
What process allows plants and algae to remove carbon dioxide from the environment?
Photosynthesis
What seasonal process mixes surface and deep water in freshwater lakes?
Lake turnover
In a food chain, phytoplankton are eaten by zooplankton. What trophic level are the zooplankton?
Primary consumers
What natural force causes regular rising and falling water levels in coastal estuaries?
Tides
Why is saltwater generally denser than freshwater at the same temperature?
dissolved salts
Bacteria convert atmospheric nitrogen into ammonium that organisms can eventually use. What is this process?
Nitrogen fixation
During fall turnover, nutrients from decomposed organisms at the bottom of a lake move in which direction?
Toward the surface
A disease kills most of the zooplankton in a freshwater lake. What will likely happen to small fish that eat them?
Their population decreases
During a full moon, stronger high tides help transport blue crab larvae away from their spawning area. What environmental factor is influencing reproduction?
Tidal changes
An aquatic plant needs sunlight for photosynthesis. Which ocean zone must it live in?
Photic zone
Dead organisms are broken down, returning nutrients to the ecosystem. What process is responsible?
Decomposition
Why does upwelling often increase phytoplankton populations near the coast?
More nutrients become available
As energy moves from one trophic level to the next, what percentage is typically transferred to the next level?
10%
A dam reduces freshwater entering an estuary. What happens to the estuary’s salinity?
It increases
DAILY DOUBLE
A fish must survive changing salinity where a river meets the ocean. What type of ecosystem is this?
Estuary
Fertilizer runoff adds excess nitrates to a lake. Which biogeochemical cycle is being directly affected?
Nitrogen cycle
A lake’s surface cools during fall, and deeper water begins rising. What happens to dissolved oxygen and nutrients as the lake mixes?
They are redistributed throughout the lake
A predator population suddenly declines. What will most likely happen to its prey population initially, assuming other conditions remain stable?
Increase
A dam reduces freshwater entering a brackish estuary. What will likely happen to organisms that require low-salinity nursery habitats?
Decline or relocate