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Charleston scientist searches for secrets of the deep

Of The Post and Courier Staff
Originally Published on: 07/26/02
Page: 1

AH: Research may help protect species during spawning

Charleston marine scientist George R. Sedberry expects to see things no human has ever seen during a scientific voyage that begins Saturday.
Sedberry hopes deep-sea dives in a submersible will reveal thousands of fish congregating to spawn, species so valued by commercial and recreational fishermen that numbers have plummeted.
If Sedberry can find the specific places and the type of habitat where these declining fish reproduce, then the sites could be protected at crucial times, and fish populations might begin to rebound.
Federal officials consider such discoveries so important that they chose Sedberry to lead the first leg of this year's "Islands in the Stream" exploration voyage. Last summer, Sedberry made deep-sea dives in the inaugural "Islands in the Stream" voyage, which concluded in Charleston amid considerable national attention.
The National Oceanic and Atmospheric Administration's new Office of Ocean Exploration is paying for and coordinating the program, this year subtitled "Exploring Underwater Oases." Last year's Islands mission yielded significant marine findings, according to NOAA officials, who describe Sedberry as a luminary in his field.
Sedberry is a senior marine scientist at the S.C. Department of Natural Resources.
Sixteen Charleston-area people including scientists from DNR, NOAA and universities and one teacher will be aboard the research vessel Seward Johnson.
Between Saturday and Aug. 5 when the team returns, Sedberry has scheduled 17 dives from northern Florida to northern South Carolina including a site off Charleston and another off Georgetown.
Fishermen and scientists have caught female fish, ripe with roe, at the sites. "We suspect they are spawning locations, and a lot of different species spawn there," said Sedberry.
But no one knows. "It is too deep, dark and murky," he said.
The deep-sea submersible Johnson-Sea-Link with its special lights, camera and arms to collect samples will take scientists down as far as 700 feet to rocky reefs and sandy bottoms up to 60 miles off the S.C. coast.
Sedberry will especially look for deepwater snappers and groupers. Vermillion and red snapper might be spawning next week, and possibly snowy grouper and gray triggerfish. Sedberry hopes to discover that dozens of species important to recreational anglers, commercial fishermen and markets use these reef areas to produce the next generation.
"That would be a first," he said, noting that human eyes haven't seen these deep-reef species spawn. Some species may reproduce as pairs; some males may collect harems; and others may form large aggregations, he said. In the tropics, for instance, divers have seen 20,000 Nassau grouper converge to spawn.
"We've been studying and catching these fish off reefs for years. We see them on a dock or dead on a boat. This is an opportunity to observe them - how they spawn, their behavior, how they are caught, what makes them vulnerable, how they avoid predators including fishermen," he said.
Learning when and where overfished species spawn would enable fisheries managers to help the fish, for example by opening the season after spawning or closing waters during spawning, a time that fishermen otherwise might catch tremendous numbers of fish before they reproduced.
The South Atlantic Fishery Management Council is considering marine protected areas as a way to increase deep-water snapper, grouper and related species; spawning sites, once they're found, might be candidates, noted Sedberry, who serves on two related council panels.
Cynthia Cooksey, a marine biologist with NOAA's National Ocean Service in Charleston, will bring home sediment and animals she gathers from inside the submersible.
"You're bound to encounter new species that have never been seen before," said Jeffrey Hyland, a principal investigator who will study what Cooksey collects. He expects to find sponges, corals, barnacles and sea anemones growing on the rocky outcrops.
The sandy soft bottom, which might resemble a desert, may be packed with worms, small clam-like mollusks and shrimp-like crustaceans, he said.
He also will look for pesticides, PCBs and other harmful contaminants that would show how mankind may be stressing life as far offshore as the continental shelf break, about 100 miles out to sea, he said.
College of Charleston geologist Leslie Sautter will examine how reefs are made.
German Ojeda of Coastal Carolina University is taking side scan sonar to map the reefs from above water. Discoveries on the submersible dives will be compared to Ojeda's readings: In the future, spawning habitat might be located without the expense of a deep-sea dive.
The "Islands in the Stream" voyage is expected to end Aug. 31 in Fort Pierce, Fla., where it begins Saturday. After the first leg along Georgia and South Carolina, second and third legs will include dives on Florida and North Carolina sites.
The expedition also will explore the unique outer continental shelf and slope habitats off the Carolinas, search for new marine life that might be developed into human medicines and investigate vision and bioluminescence in the deep-sea darkness.