WEBVTT

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My name is Santiago Herrera and I'm a visiting professor at Lehigh University. And I'm a biologist.

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The focus of my research is understanding the biodiversity patterns in the deep oceans

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and the ecological processes that happen on the seafloor.

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I study these topics primarily through the use of field observations,

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like the ones we're making here in the expedition on the Okeanos Explorer.

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Right now we are in waters of American Samoa.

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So we are looking at places that are unknown, that we have very little knowledge of .

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So this area of the world,American Samoa, is a place where there hasn't been a lot of work done below 250 meters.

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In this particular Samoan region, there are several seamounts that we have been diving.

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Every single day we have visited a different seamount.

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So a seamount is essentially an underwater mountain.

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So you can think of seamounts as islands in a sea of mud, essentially.

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So the deep areas of the abyssal plains, which are the largest habitats in the seafloor,

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these vast expanses of flat topography, get an accumulation of sediments and particles that rain down from the surface.

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That restricts the habitat for animals that need to find a firm attachment, such as a rock.

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So seamounts behave like islands in this sea of mud because, as they rise up from the sea bottom,

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they interact with the water that is moving, and those currents wash off the sediment to get

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all those nice rocks exposed that are ideal habitat for animals that require hard substrate to attach.

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So in this way, you can think of seamounts as islands of habitat, providing a space for a lot of these animals to live on.

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One of the interesting aspects about seamounts is that they also modify the currents,

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and they can cause the deep water to rise up and cause some certain

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degree of mixing with the top layers of the ocean, therefore promoting the fertilization with nutrients to the surface.

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We do have some evidence that seamounts act as places where, in general,

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you see a higher number of species compared to the surrounding seafloor.

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So you can think of them also as hotspots of biodiversity.

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So I think the information we are generating on this expedition will be of great value

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for the management of the protected areas in the American Samoa region,

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but also, the information we collect will be of great interest to the broader scientific community

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because it provides us with a picture of what the role of this region may be in the greater biogeographical puzzle of life in the seafloor.