Question

which organism could occupy the tertiary consumer trophic level in a marine food chain?
blue crab
oyster
phytoplankton
zooplankton

Explanation:

Phytoplankton are primary - producers. Zooplankton are primary - consumers. Oysters are usually filter - feeders and can be primary or secondary consumers. Blue crabs are predators that can eat other smaller animals and occupy the tertiary consumer trophic level in a marine food chain.

Answer:

Blue crab