FOR IMMEDIATE RELEASE
Oil Spill Puts Commercially Significant
Cold-water Reefs in Peril
“Hidden” Deep-Sea Ecosystems in Gulf, Florida Straits in Jeopardy
MIAMI — June 4, 2010 — Thousands of barrels of oil
are leaking out of the Deepwater Horizon site each day.
The oil ascends from depths of approximately 1502 m. (4928
ft.), but not all of it reaches the sea surface. The stratified
seawater of the Gulf of Mexico captures or slows the ascent of
the oil, and the addition of dispersants near the oil source
produces tiny droplets that float for a considerable time in
the water column and may never reach the surface.
According to Drs. Gregor Eberli, Mark Grasmueck, and Ph.D.
candidate Thiago Correa of the Marine Geology & Geophysics
division of the University of Miami (UM), the oil that remains
in suspension in the water column and creates plumes poses a
serious risk for the planktonic and benthic (sea floor) life
throughout the region, including the deep-sea reefs they study.
“The deep water communities within the Gulf of Mexico and
in the Straits of Florida are well hidden from us, but they
include many species of cold-water corals that live in water at
depths of 600 – 1500 m. (1969 -4921 ft.) in waters as
cold as 3° Celsius (37.4°F),” said Eberli.
“Unlike their more familiar shallow-water counterparts,
these corals do not live in symbiosis with unicellular algae
called zooxanthellae, but are animals that feed on organic
matter floating through the water column. We know that most of
the food consumed by the cold-water corals is produced in the
surface waters and eventually sinks down to the
The large plumes being created by the oil spill, some of which
are reported to be several miles long, sit in the water column
situated between this source of food and these deep-water
corals. As organic material sinks through the water column it
passes through the oil plumes and is contaminated by
micron-sized oil droplets.
“It is most likely that the delicate cold-water corals are
not able to digest these oil-laden food particles and will
perish in large numbers,” said Eberli. “We are
especially concerned because the migrating oil plumes have the
potential to destroy or greatly diminish these deep-sea coral
communities as they are carried by the currents. These corals
are important because they are the foundation of a diverse
ecosystem that at last count includes over 1,300 marine
species, according to Dr. Thomas Hourigan at NOAA.”
There is also a danger that these plumes are carried by the
Loop Current from the Gulf of Mexico to the Atlantic Ocean.
Deep-sea coral ecosystems are common at numerous sites from the
eastern Gulf of Mexico through the Straits of Florida and
northward to the Blake Plateau off North Carolina. This
distribution matches the path of the Loop Current that forms
from the water masses in the Gulf of Mexico, and enters the
Straits of Florida to form the Florida Current and further
north the Gulf Stream.
Particularly vulnerable to disturbance are deep-sea fish that
form part of this ecosystem because of their late maturation,
extreme longevity, low fecundity and slow growth. Deep-water
coral reefs in Florida waters are the habitat of the
economically valuable grouper, snapper and amberjack. These and
other species inhabit hundreds of deep-water coral reefs off
the coast of Florida at depths of about 300 -915 m. (1000 to
3000 feet), which were explored by Dr. John Reed from Harbor
Branch Oceanographic Institute some thirty years ago. This
includes the 59,500 sq. m. (~23,000 sq. mi.) of deep-water
reefs off the east coast of Florida, which is now proposed as
the Oculina Habitat Area of Particular Concern.
There is no known technique to clean the water column from
these oil plumes, and as a consequence the hidden oases of
corals in the deep, cold waters of the Gulf of Mexico, the
Straits of Florida and the Blake Plateau are in severe danger
of being decimated by this oil spill.
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