A student studying a pond ecosystem notices that the population of water fleas (zooplankton) suddenly increases. Based on food web interactions, which of the following is the most likely explanation?

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Question

A student studying a pond ecosystem notices that the population of water fleas (zooplankton) suddenly increases. Based on food web interactions, which of the following is the most likely explanation?

Accepted Answer

The population of small fish that eat water fleas decreased — If the predators of water fleas (small fish) decrease in number, predation pressure on water fleas is reduced, allowing their population to grow. This is an example of how changes in predator populations cascade down the food web to affect prey populations.

Answer

The concentration of dissolved oxygen in the pond increased

Answer

The water temperature fell significantly below normal

Answer

The population of small fish that eat water fleas decreased

Answer

The population of phytoplankton decreased rapidly

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