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Deepseawaters Home Deepsea
TechnologyOcean Bottom
Ocean Bottom
 The
ocean floor, also called the bottom or benthic
area of the Sanctuary, provides a diversity of habitats for
both benthic dwelling organisms, as well as those that forage
but do not necessary dwell there, such as gray
whales. We learn about habitats of the seafloor
using several tools including geophysical remote sensing devices,
bottom sampling and underwater video. The remote sensing tools
use acoustics or sound to produce data that is processed into
imagery for interpretation of substrate, depth, and features
on the seafloor. flatfishCommon remote sensing tools include
side scan sonar and multibeam. Interpretation of remote sensing
data is verified using seafloor samples or underwater video.
Using this information we classify the habitats of the sanctuary
by substrate type, depth, slope, relief and morphology. As
we gather information on the composition of benthic communities,
we also associate these with the habitat information. Bottom
samples and underwater video provide us information on the
benthic communities inhabiting the Sanctuary.
 The
seafloor of the Sanctuary encompasses over 3,300 square miles.
To date we have mapped only about 20 percent of the seafloor,
so we still know relatively little about the habitat and benthic
communities in the Sanctuary. Each year we conduct more seafloor
mapping and habitat classification, and studies to learn about
benthic community composition. In June 2004, aboard the NOAA
Ship McArthur II, we used our side scan sonar mapping data
to select likely targets for underwater viewing of deep sea
corals and sponge, and verification of the side scan data
interpretation. Using a remotely operated vehicle
(ROV) equipped with a video camera, we were able to video
tape the seafloor and benthic communities. We did indeed find
both soft and hard corals, as well as several species of sponge!
 Prior
to remote sensing, a common tool for seafloor mapping was
to take soundings and bottom samples. Maps of the Sanctuary
seafloor have been created using these data to provide preliminary
information about the seafloor.
These methods are antiquated and provide only spot data that
must be extrapolated for areas between the samples. sea cucumber
From these data, and the remote sensing data we have collected,
we have a picture that will be improved upon with detailed
knowledge over time. Benthic habitats in the Sanctuary range
from sand and mud bottoms, to pebble, cobble and bedrock,
from depths extending from the intertidal to 1,477 meters
(4,800 feet) in the Quinault Canyon.  Within
the Sanctuary boundary are the heads of three submarine canyons,
Nitinat, Juan de Fuca and Quinault from north to south, and
troughs of the Juan de Fuca Canyon extend throughout the northern
portion of the Sanctuary. metridium anemones Sand waves, from
less than a meter tall to several meters tall have also been
documented. As we gain knowledge about the habitat and the
benthic communities, we will be able to study the associations
between the two, allowing us to predict communities where
we have not yet explored, slowly allowing us to piece together
a picture of the ocean floor.
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