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Protecting California's Seamounts

Seamounts are biodiversity hotspots in the ocean. Typically seamounts are underwater volcanoes that rise up more than 3,000 feet from the seafloor.


Islands, such as the Hawaiian islands, form when these volcanoes break the ocean surface. Due to their size and shape, seamounts exert a strong influence on local currents that results in nutrient enrichment and increased food supply. These massive features are often highly productive ‘oases’ in the deep sea, supporting a large diversity of species including pelagic species such as tuna, sharks, billfish, seabirds, sea turtles, and marine mammals, as well as benthic organisms such as cold-water corals and other invertebrates.

Photo: NOAA
Photo: NOAA

The majority of known coral species exist in the dark, cold waters of the deep sea. Known as 'cold-water corals', they form complex structures that provide shelter and food for vast numbers of fish and invertebrate species. Deep coral reefs take hundreds to thousands of years to grow, and many individual deep-sea coral colonies can live for centuries. The fragility, longevity and slow growth rate of deep-sea corals make them extremely slow to recover from disturbance. Cold-water corals and the benthic communities they support are often located on the highly productive flanks and summits of seamounts.

The advent of technology capable of exploring these remote seamount ecosystems has also exposed the substantial damages already being incurred by human activity. Benthic deep-sea ecosystems are extremely fragile, and therefore highly vulnerable to physical damage from bottom trawling fisheries. Deep coral reefs are often targeted for bottom trawling because they house a large number of commercially fished species. Like other marine organisms, deep-sea corals are also sensitive to pollution, sedimentation and the effects of climate change. Even as we fight to protect these ecosystems from destructive fishing a new threat, deep seabed mining, is emerging. Restoring deep-sea environments after damage has occurred is often prohibitively expensive or impossible with modern technology, making preemptive conservation activities critical for preserving these vulnerable and ecologically vital habitats.

Join the movement to protect seamounts on the US west coast.

In the waters off the coast of California, scientists estimate that there are more than 60 seamounts supporting an impressive array of deep-sea corals, sponges, fish, sharks, sea turtles, seabirds, and marine mammals. Marine Conservation Institute is committed to protecting these seamounts through a combination of rigorous science and advocacy. In 2015, we co-founded the California Seamount Coalition to better protect these deep sea treasures. In 2019, working with Mission Blue, California's seamounts were designated a Hope Spot by Dr. Sylvia Earle.

Through our deep-sea research and conservation efforts, we are working to ensure that destructive fishing practices, oil and gas exploration and development, and future human impacts are eliminated form these vulnerable habitats. We collaborate with scientists and conservation organizations to map threats to the deep sea, generate predictive models for deep-sea coral habitats, support efforts to protect deep-sea habitats through regulatory processes to designate vulnerable marine ecosystems (VMEs), and advocate for the creation of new protected areas.

Photo: NOAA
Photo: NOAA

Check out our interactive story maps that highlight the diversity and beauty of the California seamounts!

Join us in protecting fragile seamounts. Please visit our Take Action page to become a Seamountaineer, or Donate to make our oceans healthier for us and future generations.