In a lake with three trophic levels (non-native fish, zooplankton, algae), an algal bloom occurs when the small population of zooplankton declines due to the predation of the invasive fish. Which of the following describes why zooplankton are the keystone species in this scenario? Zooplankton are the smallest of all the herbivorous marine mammals in their communities.
The small population of zooplankton have an unequal effect on the marine community.
Marine mammals depend upon the work of zooplankton to convert sunlight into food.
Zooplankton help other populations survive by keeping out other herbivores.

How do temperature and salinity affect deepwater currents? question 15 options: as temperatures and salinity levels of water increase, the water rises to the surface where it creates currents as it moves to colder regions. they create changes in wind direction, moving denser water in the same direction as the wind and causing the deepwater circulation patterns found in the ocean. they equalize the forces on undersea currents caused by the coriolis effect as they replace more dense water with less dense water. they create density differences that cause dense deepwater currents to flow toward the equator where they displace less dense, warmer water above them.