LEFT: Joanne Harcke, conservation and research coordinator at the Roanoke Island aquairum, checks out a basin of zooplankton called 

 rotifers that are food for blue crab larvae. RIGHT: Harcke's algae buffet forms another part of the diet for developing crab larvae. 



"One problem," Harcke says, "is how do 

 you tell hatchery-reared from wild crabs." 

 They look the same, she explains, and tagging 

 would be difficult because they go through 

 frequent molts. 



Marc Turano, who oversees the Blue 

 Crab Research Program for Sea Grant, says 

 that while the issue of stock enhancement is 

 debated among researchers, fisheries managers 

 and others, he is enthusiastic about the success 

 Harcke has had with raising crabs in the lab. 



"Through her work, we have learned a lot 

 about the life cycle — and we have learned a 

 lot about the food preferences — of blue 

 crabs," he says. 



People who enjoy visiting the Roanoke 

 Island facility may be surprised to learn the 

 aquarium is more than a nice place to visit. 



"As members of the American Zoo and 

 Aquarium Association, the North Carolina 

 Aquariums are encouraged to conduct original 

 research and collaborate with other researchers 

 on both in situ and ex situ projects. We're 

 committed to establishing field conservation 

 programs in North Carolina," Harcke explains. 



As to collaboration with others, this 

 project gets a little help from crabbers as well. 



Endurance and the Crab 



Murray Bridges is one of the crabbers 

 who supplies Harcke with sponge crabs. 



On the dock at his company. Endurance 

 Seafood, near Colington, Bridges points out a 

 crab beginning to shed. An opening has 



formed between top and bottom shells at the 

 back end. Slowly, the peeler slides out of its 

 former self — delicate legs last. 



Now it is vulnerable — a soft-shell crab 

 — and a more valuable commodity with an 

 edible shell. Before long, its shell would 

 harden in the wild, but this one will stay soft 

 as it is packed in ice and readied for shipment 

 to the Fulton Fish Market in New York. 



Soft-shell crabs bring good money. If 

 they didn't, Bridges says, there wouldn't be 

 many soft-shell crabbers. 



Tending peeler crabs is an around-the- 

 clock job, indeed requiring endurance. In 

 early spring, Bridges says, everybody's still 

 smiling, but when business picks up, moods 

 change with the workload. In a busy season, 

 he can have 100 shedding boxes going. 



Bridges is skeptical about reports of a 

 decline in crab abundance. He has been 

 crabbing for 30 years now and says, "I really, 

 in this area here, haven't seen that much of a 

 decline in crabs." 



"There are those that holler about a 

 decrease in crabs, and I say 'come out with 

 me.' " 



Bridges and other crabbers who supply 

 Harcke with sponge crabs know how to 

 handle them gingerly. "Careful handling of 

 female crabs from the time the crabbers 

 remove them from the pots until they enter 

 the hatchery is critical for the success of the 

 project," Harcke explains. 



"They are carefully hand-selected to cut 



down on mortality," she says. If sponge crabs 

 become stressed, they can tear the eggs off 

 prematurely, Harcke attests. 



Even though he hasn't seen a decrease 

 in crab numbers, Bridges says, "I really 

 support what she's doing. I think it's a great 

 thing to start raising them." 



It's not that Bridges doesn't see 

 fluctuations in crab catches — he just sees 

 them as natural. He says 2002 saw a "big 

 change" in harvests, but he attributes this to 

 the drought, which caused salinity to go up to 

 18 to 20 parts per thousand. Normal is 12 for 

 his location, he explains. 



Then there was the year of the hurri- 

 canes, when fresh water flooded the estuaries 

 and. Bridges says, the crabs were pushed out 

 by salinity changes. 



As temperatures warm each spring, 

 female peelers are targeted by crabbers. 



Female blue crabs about to undergo a 

 final molt seek out mature males, called 

 jimmies, for mating and protection. A jimmy 

 cradles the female, protecting her until she 

 sheds. 



Soft-shell crabbers capitalize on this 

 process by using jimmies as bait. Bridges 

 usually catches 10 to 15 per pot — some- 

 times many more with a good jimmy. 



This is the only time in the female's life 

 that she is capable of reproduction and the 

 last time she will molt. She holds the sperm 

 until conditions are right for forming the 

 sponge, or egg mass. 



14 HIGH SEASON 2003 



