Summary
Phytoplankton support zooplankton, fish and top predators, with energy lost at each level.
In depth
Energy transfer efficiencies are around 10 percent. Microbial loop recycles nutrients. Top predators such as tuna and sharks are reduced by fishing, a process called fishing down the food web.
Microbes dominate energy flow in the oceans. Zooplankton vertical migration transfers carbon. Overfishing alters web structure.
Example: forage fish like sardines link plankton to predators.
Marine food webs begin with phytoplankton (and in coastal zones, seaweeds, seagrasses), which are eaten by zooplankton, small fish and filter feeders, then by larger fish, squid, seabirds and marine mammals. Only about 10 percent of energy passes between trophic levels, so top predators are rare.
Microbial loops recycle dissolved organic matter through bacteria and protists. Marine chains are longer than those on land (four to five levels), because plankton are tiny and size-based feeding is common. Removing a key group, such as overfishing of predators, can cause trophic cascades.
Example: a baleen whale food chain is short: phytoplankton to krill to whale.
Key idea: ocean webs are tightly linked, so disturbances spread.
Frequently asked questions
What is Marine Food Webs?
Phytoplankton support zooplankton, fish and top predators, with energy lost at each level.
Which area of biology covers Marine Food Webs, and how advanced is it?
Marine Food Webs is one of the 54 topics in Marine & Environmental Biology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Biological Pump, Marine Microplastics Biology, Upwelling.
Can you give an example of Marine Food Webs?
The Antarctic food web depends on krill.
What should I learn before Marine Food Webs?
Work through the Beginner topics in Marine & Environmental Biology first, such as Oceans, Ocean Zones, Plankton, then return to Marine Food Webs. Intermediate topics assume the Beginner vocabulary.
What topics are related to Marine Food Webs?
The closest topics to Marine Food Webs are Biological Pump, Marine Microplastics Biology, Upwelling, Sharks and Rays. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Marine Food Webs?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Marine Food Webs. To practise the whole of Marine & Environmental Biology, use the Marine & Environmental Biology quiz.
How is Marine Food Webs different from Biological Pump?
Marine Food Webs: Phytoplankton support zooplankton, fish and top predators, with energy lost at each level. Biological Pump: Sinking organic matter transports carbon from surface waters to the deep ocean. Read both side by side and note what each one explains.
How should I study Marine Food Webs step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Biological Pump and explain the difference aloud. Finally, take the Marine & Environmental Biology quiz and come back to this page for any question you miss.