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Bagged, tagged and returned for research

Pity the yellow-lipped fish that researchers are catching, tagging and releasing on Gray's Reef this month.

First, they get hooked and hauled aboard a ship. Scientists then poke the groupers, some as old as 20 years, with a hypodermic needle to deflate their gas bladders, which give them buoyancy.

After a day or so of rest, the fish undergo a brief surgery to insert a transmitter the size of a AAA battery in their abdomens. Finally, an external tag is punched through the base of the fin on their backs. Only then, when they're visually identifiable and able to send out data on their whereabouts to curious scientists, are they plopped overboard to resume life on their limestone ledges undersea.

"When I think what these fish are going through, I think alien abductions," said Greg McFall, the research coordinator for Gray's Reef National Marine Sanctuary, an underwater treasure located about 17 miles east of Sapelo Island. "The other fish are never gonna believe it when they go back and retell this story."

McFall and co-investigator Matt Kendall hope the fish will tell a true-life story to them, one that details where they go so they can be better managed in the future.

Along with grouper, the pair are also catching snapper for the study.

"We don't know if there's one ledge they call home," Kendall said.

"Do they go to the shelf edge to spawn and then come back or do they jump around?"

A better managed sanctuary may eventually lead to more fish there, they say. That's important for groupers, the lions of Gray's Reef.

"It's one of the biggest animals you can see on the reef beside a shark," Kendall said. "This is what people come out to fish for."

Gray's Reef is one of the largest near-shore live bottom reefs in the Southeast. It's a popular site for recreational fishing and scuba diving.

McFall and Kendall want to tag between 20 and 42 groupers or snappers. The first two days' catch total of four made that seem a bit lofty, though by Monday morning they were up to a dozen.

An array of computerized receivers strategically placed around the reef will record the unique ping each tagged fish will make. An analysis of the data should show where the fish go over the next two years.

If they're caught by sport fishermen during that time, a small yellow tag on their back fin identifies them as research subjects.

Researchers would prefer that live tagged fish get thrown back. If the fish is dead, they request the fisherman send the $300 transmitter back to NOAA for a reward of Gray's Reef caps and T-shirts.

And because groupers are sequential hermaphrodites - they all start out as females and as they grow some develop into males - the scientists would like to get back the sex organs of any tagged dead fish.

"We'd like to see if they're males or females," Kendall said.

Look out for tagged fish

Beginning this month, scientists at Gray's Reef will be tagging snapper and grouper with small internal tags that emit a unique "ping" audible only to receivers that will be placed around Gray's Reef.

The scientists ask fishermen who catch any of these fish, identifiable by a small tag attached to its dorsal fin, to return it to the water.

Note the tag number and location of capture/return and call 598-2345 to report the information. If the fish is dead, note the location of capture and return the internal tag found in the abdominal cavity along with the fish's gonads if possible.

Anyone who accidentally pulls up a receiver is asked to call 598-2345. Scientists will retrieve the unit and return it to the water in the appropriate location to continue tracking fish.