NRES 250 EXAM 3 QUESTIONS AND ANSWERS
FISHERIES - CORRECT ANSWER✅✅
How does stratification occur? - CORRECT ANSWER✅✅Layering of water based on temperature due to
the seasons
What are the layers of mixing lakes? - CORRECT ANSWER✅✅Epilimnion: Top Warmest (Summer)
Coldest (winter)
Metalimnion: Middle mixed
Hypolimnion: Bottom (coldest water, sometimes oxygen starved.)
When is the warmest water on top Vs. the bottom of a lake? - CORRECT ANSWER✅✅Warmest water is
on top during the summer, but in winter the warmest is on the bottom
Which is more productive? o Eutrophic vs. Mesotrophic vs. Oligotrophic - CORRECT
ANSWER✅✅Eutrophic lakes are the most productive, followed by mesotrophic, then oligotrophic
littoral vs limnetic - CORRECT ANSWER✅✅Littoral- the shallow, well-lit waters close to shore, rooted
plants
Limnetic- farther from shore, where water is too deep to support rooted aquatic plants, with light
Benthic vs. Pelagic - CORRECT ANSWER✅✅Benthic zone describes the layers closer to the bottom of
the water body, and pelagic zones is layer which includes the free water column that interacts with the
surface layers of a water body (open water).
Photic vs. Aphotic - CORRECT ANSWER✅✅Photic Zone: the upper layer of a body of water delineated
by the depth to which enough sunlight can penetrate to permit photosynthesis.
Aphotic Zone: The aphotic zone is the portion of a lake or ocean where there is little or no sunlight.
, Riverine zone - CORRECT ANSWER✅✅The region of a reservoir where river water enters. Flow is fast
and the river is more narrow
Transitional zone - CORRECT ANSWER✅✅Area where river becomes wider and flow becomes slower
Lacustrine zone - CORRECT ANSWER✅✅Area of the river where it is at its largest and flow is at it's
slowest. Almost seems lake like
How do flow, visibility (turbidity), and organic inputs vary among the three reservoir zones - CORRECT
ANSWER✅✅Riverine: There is no stratification and has turbulent flow. Carries organic matter
Transitional: Sediment deposition
Lacustrine: Stratification
When are nutrients the highest in a reservoir? - CORRECT ANSWER✅✅During the spring and early
summer months due to snow melt and runoff
What are the ecological services (roles) do wetlands provide? - CORRECT ANSWER✅✅Essential wildlife
and fish habitat- Spawning- Nursery- Migration•
Ecosystem services- Water storage to mitigate flooding and erosion- Reduce sediment and nutrients to
improve water quality- Sequester atmospheric carbon- Groundwater recharge
What do fish use wetlands for? - CORRECT ANSWER✅✅They can use wetlands as spawning grounds
and nursing areas for young
What is an ephemeral wetland? - CORRECT ANSWER✅✅Wetlands that are only saturated during the
spring
How do land use practices in the watershed affect stream habitats? - CORRECT ANSWER✅✅a lack of a
riparian buffer, allowing cattle crossing, and not having cover crops allow a lot of runoff and sediment to
enter the river.
FISHERIES - CORRECT ANSWER✅✅
How does stratification occur? - CORRECT ANSWER✅✅Layering of water based on temperature due to
the seasons
What are the layers of mixing lakes? - CORRECT ANSWER✅✅Epilimnion: Top Warmest (Summer)
Coldest (winter)
Metalimnion: Middle mixed
Hypolimnion: Bottom (coldest water, sometimes oxygen starved.)
When is the warmest water on top Vs. the bottom of a lake? - CORRECT ANSWER✅✅Warmest water is
on top during the summer, but in winter the warmest is on the bottom
Which is more productive? o Eutrophic vs. Mesotrophic vs. Oligotrophic - CORRECT
ANSWER✅✅Eutrophic lakes are the most productive, followed by mesotrophic, then oligotrophic
littoral vs limnetic - CORRECT ANSWER✅✅Littoral- the shallow, well-lit waters close to shore, rooted
plants
Limnetic- farther from shore, where water is too deep to support rooted aquatic plants, with light
Benthic vs. Pelagic - CORRECT ANSWER✅✅Benthic zone describes the layers closer to the bottom of
the water body, and pelagic zones is layer which includes the free water column that interacts with the
surface layers of a water body (open water).
Photic vs. Aphotic - CORRECT ANSWER✅✅Photic Zone: the upper layer of a body of water delineated
by the depth to which enough sunlight can penetrate to permit photosynthesis.
Aphotic Zone: The aphotic zone is the portion of a lake or ocean where there is little or no sunlight.
, Riverine zone - CORRECT ANSWER✅✅The region of a reservoir where river water enters. Flow is fast
and the river is more narrow
Transitional zone - CORRECT ANSWER✅✅Area where river becomes wider and flow becomes slower
Lacustrine zone - CORRECT ANSWER✅✅Area of the river where it is at its largest and flow is at it's
slowest. Almost seems lake like
How do flow, visibility (turbidity), and organic inputs vary among the three reservoir zones - CORRECT
ANSWER✅✅Riverine: There is no stratification and has turbulent flow. Carries organic matter
Transitional: Sediment deposition
Lacustrine: Stratification
When are nutrients the highest in a reservoir? - CORRECT ANSWER✅✅During the spring and early
summer months due to snow melt and runoff
What are the ecological services (roles) do wetlands provide? - CORRECT ANSWER✅✅Essential wildlife
and fish habitat- Spawning- Nursery- Migration•
Ecosystem services- Water storage to mitigate flooding and erosion- Reduce sediment and nutrients to
improve water quality- Sequester atmospheric carbon- Groundwater recharge
What do fish use wetlands for? - CORRECT ANSWER✅✅They can use wetlands as spawning grounds
and nursing areas for young
What is an ephemeral wetland? - CORRECT ANSWER✅✅Wetlands that are only saturated during the
spring
How do land use practices in the watershed affect stream habitats? - CORRECT ANSWER✅✅a lack of a
riparian buffer, allowing cattle crossing, and not having cover crops allow a lot of runoff and sediment to
enter the river.
