Summary
Wind-driven rise of cold, nutrient-rich water that fuels some of the ocean's richest fisheries.
In depth
Occurs along western coasts (Peru, California, Namibia) and equatorial regions. Peru's upwelling supports anchoveta fisheries, which collapse during El Niño. Upwelled water also brings CO2 and low oxygen.
Ekman transport moves surface water offshore, drawing deep water upward. El Niño suppresses upwelling off Peru. Upwelling supports seabird and marine mammal populations.
Key idea: upwelling brings nutrients to sunlit surface waters.
Upwelling is the vertical movement of cold, nutrient-rich deep water to the surface. Along coasts, winds blowing parallel to the shore push surface water away (Ekman transport), and deep water rises to replace it, as off Peru, California, Namibia and northwest Africa. Equatorial and Antarctic upwelling also occur.
The nutrients boost phytoplankton blooms that feed zooplankton, anchovies, sardines, seabirds and marine mammals; upwelling regions cover about 5 percent of the ocean but yield about 25 percent of the global fish catch. During El Nino, upwelling off Peru weakens, causing fisheries to collapse.
Example: the Humboldt Current supports the world's largest single-species fishery, the Peruvian anchovy.
Frequently asked questions
What is Upwelling?
Wind-driven rise of cold, nutrient-rich water that fuels some of the ocean's richest fisheries.
Which area of biology covers Upwelling, and how advanced is it?
Upwelling 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 Oceans, Marine Food Webs, Thermohaline Circulation.
Why does Upwelling matter?
It links winds, nutrients and food.
Can you give an example of Upwelling?
Upwelling regions cover 5 percent of the ocean but produce about 25 percent of fish catch.
What should I learn before Upwelling?
Work through the Beginner topics in Marine & Environmental Biology first, such as Oceans, Ocean Zones, Plankton, then return to Upwelling. Intermediate topics assume the Beginner vocabulary.
What topics are related to Upwelling?
The closest topics to Upwelling are Oceans, Marine Food Webs, Thermohaline Circulation, Overfishing. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Upwelling?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Upwelling. To practise the whole of Marine & Environmental Biology, use the Marine & Environmental Biology quiz.
How is Upwelling different from Oceans?
Upwelling: Wind-driven rise of cold, nutrient-rich water that fuels some of the ocean's richest fisheries. Oceans: Salt water covering about 71 percent of Earth, home to most of the planet's living space. Read both side by side and note what each one explains.
How should I study Upwelling 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 Oceans and explain the difference aloud. Finally, take the Marine & Environmental Biology quiz and come back to this page for any question you miss.