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Did Millenia of Fish Poop Help Shape a New Seamount off the Coast of California?

“The oceans deserve our respect and care, but you have to know something before you can care about it.” – Sylvia Earle

Move over boring geological processes – there’s a new seamount in town that scientists say could have been shaped by a surprising source: fish poop. Seamounts are colossal underwater mountains that usually form through volcanic activity, similar to the way terrestrial volcanoes form. However, the newly discovered seamount off the coast of California has an unusual shape, with steep sides and a cratered summit, suggesting that biological processes could also have played a role in its formation. NOAA Ocean Exploration Cooperative Institute manager Dr. Aurora Elmore explained that the new seamount’s shape could have partially resulted from the slow accumulation of marine snow, the shower of organic particles drifting down through the water column from more productive surface waters. Care to go explore an underwater mountain formed by “millennia of fish poop”?

Bathymetry showing the height and unique shape of the newly discovered seamount. Courtesy of Saildrone/NOAA.

The seamount, still unnamed, was discovered on a joint NOAA and Saildrone mission that mapped a large area off the coast of Cape Mendocino, California. Saildrone makes and operates autonomous (uncrewed and unpiloted) sailing vessels that can collect a large range of oceanographic data including temperature, salinity, carbon dioxide, current speed, and bathymetry to order to improve ocean models, monitor climate change, explore new areas, and support scientific research. Their vessels operate at relatively low speeds of 2-8 knots, but have an extremely large range of up to 16,000 nautical miles and an impressive endurance of up to 12 months.

You may be surprised to hear that we are still discovering seamounts – they are, after all, massive features that have typically been around for millions of years. Despite extensive effort and vast technological advances, we’ve still only mapped about 25 percent of the seafloor at a high resolution, giving rise to the popular notion that we know more about the surface of Mars than we do about our own ocean. The entire ocean has already been mapped by satellites, but at a very course resolution that often fails to show important features, like the incredible new seamount discovered when Saildrone mapped this area at a much higher resolution.

One of Saildrone’s autonomous sailing vehicles. Photo courtesy Saildrone and NOAA.

The new seamount joins the other 63 seamounts already known to exist in the federal waters off the coast of California. Seamounts support incredible levels of biodiversity, acting as hotspots of life in the often sparsely populated deep sea, including cold-water corals, sponges, and fish not found in any other habitats. In addition, seamounts have a unique geological history that can provide important insights into the formation and evolution of the Earth’s crust and the processes that shape our planet. Due to their massive size, seamounts also strongly influence surface productivity and diversity by creating upwelling areas that bring nutrients to the surface, fueling a large food web that supports organisms from the smallest zooplankton to the largest animal to ever roam the planet – the blue whale.

Marine Conservation Institute is dedicated to enhancing protection for seamounts off the coast of California and beyond. The discovery of a new seamount so close to home highlights that we still have much to learn about the critical ocean habitats that exist right off our own coastlines. As such, it is crucial to take a precautionary approach to ocean management to avoid inadvertently causing harm to these delicate systems. This means avoiding actions – like destructive fishing practices, oil and natural gas extraction, or deep-seabed mining ­– that may cause harm to vulnerable habitats unless the ecological impacts of these activities are completely understood and fully mitigated. Despite all that we know about the other seamounts off the coast of California, only one has been granted strong protection, leaving the others – including the newly discovered seamount – vulnerable to disturbance from human activities. Join us in the fight to protect seamounts both in the waters off the coast of California and around the world!