Scientists get fish's
eye view of reef life
By: LYNNE LANGLEY
Of The Post and Courier
Staff
Originally Published on: 08/02/02
Page: 1 See PDF for Sheils map entitled 'Deep Reef Mission'
Some 60 miles east-southeast of Charleston, marine scientist George
Sedberry prepared Thursday for his next deep-sea dive and made notes
about the brightly colored fish he'd watched 200 feet beneath the surface
at the St. Augustine Scarp.
"We have seen many exciting things," Sedberry reported via
e-mail from aboard the research vessel Seward Johnson.
The S.C. Department of Natural Resources senior scientist is principal
investigator on the national Islands in the Stream 10-day exploratory
voyage that departed from Fort Pierce, Fla., last Saturday.
The next day Sedberry descended in a submersible to investigate spots
no human had ever seen and to learn what biologists and fishermen alike
have only pondered.
On what Sedberry described as a spectacular shelf-edge reef about 200
feet down, he observed beautiful tropical fish such as queen angelfish,
rock beauty, yellowtail reef fish, squirrelfish and many others.
"The diversity of fish and the bright colors of sponges, corals
and other encrusting invertebrates gave the rocks a colorful glow that
ranged from red to orange to lime green and purple," Sedberry said.
He hoped to find spawning sites of fish that commercial and recreational
fishermen value so highly that the species are dwindling and need help.
So far, Sedberry hasn't seen that activity, but all the signs are right.
Scamp grouper sported spawning colors: A few large males wore the aggressive
"gray head" phase that they display to attract and keep a
small number of females around them, Sedberry said, and several smaller
females were swimming alongside a large gray-head male.
He also observed smaller females beside a large male hog snapper whose
color display Sedberry described as spectacular.
The dives at the St. Augustine and Jacksonville scarps could prove especially
useful, because both are being considered as Marine Protected Areas.
Fishing could be restricted, for instance during spawning season, if
biologists knew when important fish congregated.
This week's dives also would provide baseline data, for comparison,
to see whether any future protection brought an increase in snapper
and grouper to the sites, Sedberry said.
"I was amazed at the beauty of the reef and the amount of rock
habitat. I was troubled by the few fish seen on the reef. ... It seemed
very empty in many places. Some spots did, though, have a fair number
of scamp grouper, and it appeared as if they were spawning there."
Large rocks at depths of 175 to 200 feet formed a relatively narrow
ribbon running south to north for at least 30 miles, at the edge of
a scarp where the bottom dropped 20 to 30 feet along a rocky ledge.
"The rock pile resembles the remains of an ancient city, such as
Mayan ruins or other fallen pyramids," scientists told Sedberry.
"The rocks themselves were squared-off boulders the size and shape
of small refrigerators," said College of Charleston geologist Leslie
Sautter. "At times they were almost perfectly aligned in a grid
pattern, and one could imagine that they'd been carefully arranged on
the seafloor."
Sautter says the shapes probably resulted from faulting of the limestone/sandstone
rock exposures.
The next dive revealed the Jacksonville Scarp to be large, irregular
rock rubble with a thin layer of sand blanketing a hard rock pavement.
Arms on the submersible gathered five large boulders, each completely
covered by sponges, soft coral, bryozoa and crustaceans. "These
rocks truly are the substrate on which the reef ecosystem is founded,"
Sautter added.
Two scientists at a time dive aboard the submersible to collect creatures
and sediments and to observe and make videotapes of previously unseen
activity.
Pam Cox Jutte, DNR assistant marine scientist who expects to dive on
Scamp Ridge today, wanted to observe sponge and coral communities at
deep reefs. "We haven't been disappointed," she said of an
earlier dive. She reported abundant black coral about 4 feet tall that
pop from the seafloor like coiled bed springs.
Scientists collected several species of vibrantly colored sponges, which
Jutte described as undersea hotels for a host of organisms. She will
study the sponges in detail in her Charleston lab and, she wrote in
an e-mail, "New species of small crustaceans or worms might be
discovered living within the sponges."
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