Liz Hoadley: I'm Liz with NOAA Ocean Exploration.
Today, we're taking a closer look at the volcanoes that
lie hidden beneath our ocean.
Known as seamounts these features provide critical habitat for marine organisms.
And act as a geologic record that can help us understand the forces that
have shaped our world, quite literally.
Thomas Morrow, a marine geologist and geophysicist with our office
is here to tell us a little more.
Thomas Morrow: Thanks Liz.
That's right.
There's a lot we can learn from seamounts.
Scientists estimate that there are tens of thousands of these features
across the world, in every ocean basin, but only a small percentage
of them have been explored.
In the simplest of terms, a seamount is an underwater volcano.
If you picture a volcano, you can imagine lava erupting out of the
top and spilling over the sides.
As that lava cools it hardens into solid rock and a volcano grows.
Seamounts are created through volcanic processes.
So they're usually found near the edges of tectonic plates or near volcanic hotspots.
Whatever their origin, seamounts follow the same general life
cycle over millions of years.
Their shapes can vary depending on volcanic activity and erosion.
Islands also face wave, wind and rain erosion, and will eventually
erode back down below the oceans surface, sometimes forming guyots
type of seamount with a flat top.
Geologically seamounts are fascinating because they tell us the story of
our planet over millions of years.
They can record the movements of tectonic plates and their lava and
rock compositions can tell us about the deep, hidden parts of our planet.
Biologically, they can also have a huge impact on life in the ocean.
Liz Hoadley: Thomas, thank you so much.
That really is fascinating.
Thomas Morrow: Thanks Liz.
Liz Hoadley: On that note.
We're lucky enough to have another scientist here to tell us more about
what sea mounts mean for ocean biology.
Meagan Putts is a deep-sea research associate at the University
of Hawaiʻi studying deep sea coral and sponge communities.
And she has explored many seamounts using remotely operated vehicles.
Welcome Meagan.
Meagan Putts: Hi, it's really great to be here today.
I'm excited to talk about seamounts.
Liz Hoadley: So Meagan, seamounts are frequently chosen as dive
sites for deep-sea exploration.
Can you tell us a little bit about why that is?
Meagan Putts: Absolutely seamounts are these areas of really amazing diversity
and density of organisms in the deep-sea.
So seamounts provide habitat for a number of different types of animals
like corals, sponges, fishes, crabs, shrimps, you name it you might be
able to see it down on a seamount.
Liz Hoadley: So why is it that seamounts are such hotspots for biodiversity?
Meagan Putts: That's a really great question.
There are two main reasons why seamounts are these great hot spots of biodiversity
and that substrate and current.
Across most of the ocean is abyssal plane and so it's sort of like a desert where
it's covered in these very fine mud.
So substrate on the seamounts is hard because they are
mountains made out of rock.
Animals like sponges and corals, which are sessile meaning that
they can't move around during their lifetime need to attach to something.
And that something is going to be rocks on the side of these seamounts.
And that makes these really great, beautiful communities possible.
However, ocean currents actually act to connect seamounts that
are far away to each other.
And that's because these animals that are living on seamounts that
are sessile during their adult years, actually reproduce by producing larva.
The larva can actually move from seamount to seamount by using the ocean currents.
Which is really, really exciting to scientists like myself.
And that's what we call connectivity.
This, you know, relationship between these biological communities
that are vastly far apart.
Liz Hoadley: So earlier on Thomas mentioned that there are tens of thousands
of seamounts throughout the ocean.
I'm wondering just how similar or different are they from one another?
Meagan Putts: So seamounts can tend to be very similar or extremely different
from one another, depending on where they are, what the ocean currents are
like, how those sea mounts are connected.
What I've noticed throughout the many dives that I've participated in is
that we see very similar communities at similar depths on seamounts in the
Pacific ocean and the Atlantic ocean.
Now these are not the same species.
But there are similar families that are observed and also similar types
of communities that we're observing.
So we do see some similarity, but they're also in detail, very, very different.
Liz Hoadley: Wow.
So you've really spent some time observing parts of the world
that most of us never get to see.
And others only get a glimpse of what are some other questions that
are, are current areas of research?
Meagan Putts: Well, there are thousands and thousands of seamounts
that have never been explored at all.
There are infinite questions still waiting to be answered about seamounts.
So the ones that I'm most interested are about the connectivity
that we see between seamounts.
How are those communities on one seamount similar or different from communities
in the same seamount chain or from seamounts that are, you know, on the
other side of the world from each other.
Every time we dive, we are finding new species and collecting new species.
So there are a number of taxonomists that are actively working on
describing new animals and adding that information to our vast databases on
what we know about life in the ocean.
So if you can think it, you can definitely ask it of seamounts.
Liz Hoadley: So Meagan, it's been so nice to have you here today.
I'm wondering if you have any parting remarks before you head out?
Meagan Putts: The deep-sea had always been sort of this place
that's out of sight out of mind.
Uh, but it really is no longer that because it is in sight.
We have vehicles that are live streaming from the sea floor.
You can see this deep sea floor for yourself nowadays.
So it's, it is there.
We can see it, we can explore it.
We can all participate no matter where we are in the world.
And that's really the beauty of what we do here is making
these distant places accessible.
Liz Hoadley: This is fascinating.
Uh, thank you so much for taking the time to be with us today and telling
us a little bit about seamounts and sharing your research with us.
Meagan Putts: Absolutely.
Sharing my research is one of my favorite things to do.
Thanks for having me.
Liz Hoadley: Everything we know about seamounts comes from only a small
fraction of the total number in the ocean.
This makes each one an exciting new frontier for future ocean exploration.