Julie Zeidner Russo
||Their beauty is marvelous. Far beneath the ocean,
precious corals in shocking pink, gold, alabaster, and black
dot the ancient seamounts of Hawaii. When brushed by a predator,
gold corals defense is to shoot bioluminescent sparks into the
water creating a deepsea fireworks display. Otherwise, the corals
look stately clustering on vertical limestone walls like miniature
versions of the oak forests warranted protection by our national
This perfection--paradoxically grand and delicate like the Japanese-manicured
bonsai tree--must be captured. Prized as jewelry and other ornaments,
a single ten-year old red coral can sell for $200 per lb. The precious
coral industry in Hawaii, which has been inactive for the past 20
years, is about to start up again. The industry is already valued
at more than $25 million at the retail level, according to marine
ecologist R.A. Grigg.
Tangle nets dragged across the bottom of the ocean, which yank
up branches of coral and tear apart their seabeds, are still used
in many parts of the world where regulations are not in place to
protect corals. Concern over the boom-bust cycle of precious coral
fisheries in Taiwan, Japan, and the Mediterranean, prompted resource
managers in Hawaii to set aside a refuge at the WesPac Bed in the
Northwest Hawaiian Islands. Permits are required to fish for coral
in the main Hawaiian Islands, and the coral, which can only be taken
by the robotic arms of a submarine or ROV (Remotely Operated Vehicle),
must be of reproductive maturity.
The purpose of the WesPac reserve--the only one of its kind established
in the Hawaiian Islands or the northwest Emperor Seamount Chains--is
to provide a reproductive reserve for the replenishment of corals
beds. The refuge is also designed as a baseline study area for evaluating
the effects of over-exploitation on other coral beds. But until
recently, very little was known about the life history of corals,
how they varied, or whether a sole refuge in Hawaii would serve
its purpose. Any effort to protect precious corals would depend
on reliable information about the fishery.
|That's where oceanographers Amy Baco,
George Roderick, and Craig Smith enter. In the first genetic
study of precious corals in the Hawaiian Islands, the researchers
will solve some of the mysteries associated with these distinct
stocks in research that could help pave the way for effective
management and protection of corals. Baco is a PhD candidate
and Smith, an oceanography professor, at the University of Hawaii
at Manoa. Roderick is an assistant researcher at the Center
for Conservation Research and Training. The research is funded
by NOAA's Undersea Research Program (NURP)and the National Sea
Grant College Program.
The arm of the Pisces V maneuvered the delicate task of
breaking off small pieces of 283 individual corals.
"The precious corals fishery represents a huge potential income
resource that needs to be managed properly or it's going to crash,"
Baco said. "Following a boom-bust cycle, it takes a long time (if
ever) for the fishery to recover, whereas if you manage it properly
there's a steady supply of resources."
Before the fishery can be managed properly researchers must first
figure out how deep water corals live, reproduce, and vary. "Knowledge
of stock structure, and the related issue of maintenance of genetic
diversity, are often neglected with dire consequences for the exploited
species," Roderick said. What genetic differences account for the
spectacular range of coral colors and shapes? How closely are the
corals related from one submerged island, and if so, what are the
consequences of fishing out a population? Are precious corals in
the WesPac "Refugium" sufficient for replenishing commercial beds
of corals throughout the Hawaiian Islands?
Precious corals in the Hawaiian islands take advantage of historic
volcanic activities and erosion, growing on the slopes of sunken
islands where they can best feed on particles floating by. These
"dwarf forest" coral beds at depths of 350 to 500 m., attract a
tremendous diversity of life. At least 90 different species of gorgonians
are found in the Hawaiian islands, Baco said.
Several recent genetic studies of shallow water corals in the Mediterranean
have shown evidence for genetic isolation of populations in both
hard and soft corals, Baco said. This means that a fished out population
in one area would deprive another area close by of the genetic diversity
it needs to remain healthy. While the precious corals of Hawaii
are closely related to the ones in the Mediterranean, it is not
known whether they exhibit similar reproductive strategies. "If
significant genetic structure exists in populations of precious
corals," Baco said, "this would suggest that elimination (through
overharvesting) of a bed of precious corals would result in loss
of overall genetic diversity within a species."
differences account for the spectacular range of coral colors
||On a map, precious corals look like
a tiny constellation orbiting the main Hawaiian islands. Researchers
theorize that gold, red and pink coral there have dispersed
and multiplied across the submerged islands in a stepping stone
pattern. "The issue comes down to how far these corals are able
to disperse and how closely the coral populations on different
islands are related," Baco said. "If gold corals need stepping
stones, then if you fished out one of these beds along the way,
it might be too great a distance for some of these corals to
disperse, resulting in isolation of coral populations and reduced
Six dives in the Pisces V submersible to the
precious corals beds of Makapuu and other sites
were performed by Baco last summer. The lights
of the Pisces V illuminated the brilliantly
colored corals. Its arms maneuvered the delicate
task of breaking off the small pieces of 283
individual corals. With the coral's tissue,
Baco and research assistants will be able to
analyze DNA makeup, comparing corals from four
different locations including samples from the
An interesting development occurred during
the research cruise. Baco shared dive time at
French Frigate Shoals with marine biologist
Frank Parrish of the National Marine Fisheries
Service. With funding from NURP, Parrish is
studying the endangered Hawaiian monk seal.
The researchers observed species in the coral
beds that are known to be prey of seals, and
seals in the surface water's above the site.
The seals could potentially use the coral beds
as a fishing ground. The observation prompted
fisheries and industry managers to amend harvest
regulations to protect the forage habitat.
Results of the genetic analysis will take time
to complete. However, researchers believe that
it is not too soon to begin establishing additional
coral bed refugia. "We expect to find that the
WesPac Refugium is not reseeding precious coral
beds on the main Hawaiian Islands," Baco said.
"This suggests that a number of refugia should
be established along the entire archipelago."
Information gathered from the study is sure
to substantially improve the management of the
Hawaiian coral fishery as a sustainable resource,
the researchers said.