What Are Seamounts?

Written by on October 16, 2013 in Marine Life, Physical Oceanography

What are seamounts? You asked. We answered. Here’s an overview of one of the ocean’s most common habitats.

Here you can see the heights of several seamounts in the Gulf of Alaska.

Here you can see the heights of several seamounts in the Gulf of Alaska. Photo credit: NOAA.

Seamounts are underwater mountains — mostly extinct volcanoes — that rise hundreds or thousands of feet from the seafloor and are most commonly found near the boundaries of Earth’s tectonic plates.

Seamounts provide a solid surface for deep-sea life to grow on. Rising into the water column, seamounts shape ocean currents and direct deep, nutrient-rich waters up the slope, facilitating the growth of diverse communities of marine life.

They are home to sponges, crabs, and sea anemones, as well as deep-sea corals and many species of commercially important fish, including orange roughy (Hoplostethus atlanticus) and red snapper (Lutjanus campechanus). Deep-sea corals that thrive on and around seamounts host more than 1,300 different species of animals.

Hourglass moray photographed at a seamount near Costa Rica.

Hourglass moray photographed at a seamount near Costa Rica. Photo credit: August Rode via photopin cc.

Seamounts rank as one of the most common ocean habitats in the world. It is estimated that there are at least 100,000 seamounts higher than 1,000 meters around the world. If you include seamounts smaller than 1,000m (which most scientists do), then there could be millions. There are as many as 30,000 seamounts in the Pacific Ocean alone.

Scientists are only just beginning to explore seamounts, having only studied life on about 300. Researchers are looking to answer some key questions: Are species that live on seamounts endemic to particular seamounts or seamount chains, evolving in isolation from other species? Do seamount fisheries have a future? Will seamounts be mined for heavy metals and minerals?

Pencil Urchin commonly found near deep-sea coral communities.

Pencil Urchin commonly found near deep-sea coral communities. Photo credit: Dr. Steve Ross, NOAA Office of Ocean Exploration.

To fully understand the value of seamounts, we will have to go into much more detail. Check back soon for more information on seamount exploration, fisheries and mining!


For a more detailed analysis of seamounts, check out the Oceanography Special Issue on Mountains in the Sea. Below are selections from the issue.

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Copyright © 2013 by Marine Science Today, a publication of Marine Science Today LLC.

About the Author

About the Author: Emily Tripp is the Publisher and Editor of MarineScienceToday.com. She holds marine science and biology degrees from the University of Miami's Rosenstiel School of Marine and Atmospheric Science and a Master of Advanced Studies degree in Marine Biodiversity and Conservation from Scripps Institution of Oceanography. When she's not writing about marine science, she's probably running around outside or playing with her dog. .


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