Page 6 - Deep-Sea Coral Research and Technology Program

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6
D
eep-sea corals can live for hundreds or thousands of years, creating
remarkably complex communities in the depths of the oceans
from where the light is dim to more than 10,000 feet below.
In the United States, deep-sea coral habitats have been discovered in all
regions on continental shelves and slopes, canyons, and seamounts. Their
full geographic extent is still unknown because most areas have yet to be
adequately surveyed.
Some deep-sea coral species form reefs that, over millennia, can grow
more than 300 feet tall. Other species shaped like bushes or trees can form
assemblages similar to groves or forests on the seafloor.
Nationwide, these complex structures provide habitat for many fish and
invertebrate species, including certain commercially important ones like
grouper, snapper, sea bass, rockfish, shrimp, and crab. Moreover, organisms
that live in deep-sea coral habitats produce chemicals with great potential
for biomedical uses, and some deep-sea coral species have commercial
value as jewelry and art objects.
Most deep-sea corals grow extremely slowly. Once damaged, the corals
and the communities they support may take centuries to recover, if they
recover at all. Deep-sea corals are vulnerable to disturbance caused by
fishing gears such as bottom trawls that contact the seafloor. They can
also be damaged by activities associated with energy exploration and
development, cable deployment, and other activities that disturb the
seafloor. Additionally, ocean acidification—a result of the ocean absorbing
increased carbon dioxide—can adversely affect corals’ ability to grow or
maintain their structures.
About Deep-Sea Corals
Deep-sea
stony corals
range from small in-
dividual cup corals to a few species, like this
Lophelia pertusa
colony off Eastern Florida,
that contribute to extensive deep-water
reefs.
Gold corals
, which belong to a single genus,
Gerardia
, are sometimes collected for jewelry.
They are unique in that they appear to grow
on the skeletons of other deep-sea corals and
can live for thousands of years.
Gorgonians
, like this fan-shaped colony of
red coral
(
Corallium
sp.) on Davidson Sea-
mount, are among the most diverse deep-
sea corals.
Black corals
often resemble bushes or
trees, and may include the oldest living ma-
rine organisms. This black coral off Hawaii
was estimated to be over 4,000 years old.
Sea pens
, like these off Alaska, are related to
gorgonians
, but unlike most other deep-sea
corals they live in soft sediments where they
can form large fields.
Lace corals
, like these off California, are ac-
tually hydroids and only distantly related to
other corals.