m a r i n e advice 



Summit Seeks Solutions to Sagging Oyster Production 



Used to be. along Lockwood Folly 

 River at autumn low tides, only one thing 

 eclipsed the bounty of oysters protruding 

 from the exposed mud and rock. That 

 was the strong backs of ov stermen bend- 

 ing to handpick or rake the harvest of the 

 succulent shellfish. Nearby, the town of 

 Yamum would prepare for its commu- 

 nity oyster roast to showcase the indig- 

 enous harvest and celebrate its heritage. 

 There and in similar settings throughout 

 eastern North Carolina, you couldn't 

 steam enough oysters to satisfy the 

 hordes that came to sample this local 

 delicacy. 



Today, a different picture has 

 emerged throughout the sounds and 

 embayments of coastal North Carolina. 

 The local oyster is seldom the center of 

 community gatherings. The shellfish 

 served at Tar Heel oyster roasts today 

 likely traveled from Louisiana or Wash- 

 ington. Fewer bodies bend in silhouette 

 to gather a shrinking harvest of C. 

 virginica. Recruitment, or new popula- 

 tion of oysters each season, is languish- 

 ing. Disease and polluted waters, com- 

 bined w ith poor management and over- 

 exploitation of the oyster fishery, have 

 tainted this once prolific resource. 



At the turn of the century. North 

 Carolina produced around 5 million 

 pounds of oysters each year. By the 

 1920s and '30s. annual production had 

 declined to about 2 million pounds. Dur- 

 ing the past three years, the state's feeble 

 producdon has barely reached 300.000 

 pounds, according to the N.C. Division 

 of Marine Fisheries. 



N.C. Sea Grant, the N.C. Division of 

 Marine Fisheries and other partners spon- 

 sored a summit in April to discuss direc- 

 tions for boosting the sagging oyster in- 

 dustry. Experts from other states shared 

 their experiences w ith participants. 



Our state has much company in its 

 oyster w oes. The oyster harv est in Man - 

 land and Virginia, which traditionally has 

 been much higher than North Carolina's, 

 has declined in recent years to about the 

 same level. Total U.S. production in 



1992 w as almost 30 million pounds, w ith 

 about 25 percent from the West Coast, 

 mainly Washington: 30 percent from 

 Louisiana: 20 percent from Connecticut: 

 and the remainder from the East Coast 

 and Gulf of Mexico. 



North Carolina embraces a large area 

 — about 1.8 million acres — available for 

 oyster production. But North Carolina has 

 less "oyster rock" or reef area than Vir- 

 ginia and Maryland. Also, the shellfish 

 leased acreage in North Carolina is com- 

 paratively low — about 2.600 acres. Most 

 states and countries that have increased 

 oyster production have developed some 

 type of culture/lease system. 



Management of oyster production in 

 North Carolina has lagged behind that of 

 other states. Oyster seed beds under state 

 management are very small. Individuals 

 who lease shellfish bottom from the state 

 are given little protection from poachers, 

 which limits private investment. Oyster 

 rock is on a very thin foundation: the ad- 

 dition of cultch — the hard substrate to 

 which young oysters attach — has been 

 limited. 



And during the past five years, the 

 ubiquitous oyster diseases Dermo and 

 MSX have hurt viability. These ravenous 

 protozoan or one-celled parasites first 

 appeared in North Carolina's estuarine 

 landscape in the late 1980s. Both Dermo 

 and MSX thrive in warm, salt}' waters 

 typical of tidal creeks and sounds during 

 drought conditions. Harmless to humans, 

 the parasites attack and eventually kill 

 oysters. In 1989. the diseases ravaged 

 North Carolina's oyster harvest, and ac- 

 cording to scientists, are here to stay. 



Research on oyster diseases has 

 gained some momentum in the past few 

 years with revived funding. With scien- 

 tists at the Virginia Institute of Marine 

 Science now able to culture Dermo in a 

 laboratory, they can tr\ to leam how to 

 control the disease and circumvent it. 



The disease infection cycle raises the 

 possibility for innovative management to 

 avoid mortality from Dermo. which com- 

 pared to MSX. is a slow killer. Dermo 



will cause near total mortality in a crop of 

 oysters infected for two summers. Where 

 oysters reach market size in 18 months, 

 some culturists have reversed the tradi- 

 tional planting cycle to limit exposure to 

 Dermo. which is mostly a warm season 

 phenomenon. Spat planted in the fall gets 

 its first growth period as the water is 

 cooling and Dermo is declining. The fol- 

 lowing spring, oysters pick up Dermo but 

 aren't killed. The oysters are harvested at 

 the onset of the second spring and spared 

 lethal exposure. 



Aquaculture. another focus of the 

 summit, can substantially increase oyster 

 production. North Carolina has devel- 

 oped its own innovativ e method of cul- 

 turing oysters off the bottom with a 

 grow-out system that resembles a floating 

 ladder. The "chub ladder" method, devel- 

 oped by N.C. Sea Grant specialist Skip 

 Kemp and a metal clip manufacturer, has 

 been enhanced by cooperation of the 

 N.C. Division of Marine Fisheries and 30 

 priv ate oyster grow ers. The oysters grow 

 at the surface in indiv idual mesh bags 

 sealed at both ends until harvest. This 

 "Jiffy Pop" method of culturing oysters 

 offers the advantages of low labor re- 

 quirements: the system is mobile and eas- 

 ily retrievable. 



Chub oysters reach market size in 

 about 18 months, nearly half the time it 

 takes in the wild. .And because they grow 

 near the water's surface, where oxygen 

 and food are more plentiful, they tend to 

 be healthier and less susceptible to dis- 

 eases. 



From the summit came a proposal 

 for a '"blue-ribbon committee" appointed 

 by the Legislature to address the issues of 

 rehabilitation and restoration, leasing and 

 water access, seed availability, disease 

 and aquaculture research, improved man- 

 agement and public image, and market- 

 ing. Sea Grant has produced a six-page 

 summary of the Oyster Summit with 

 recommendations. For a free copy, write 

 Sea Grant at Box 8605. NCSU. Raleigh. 

 NC 27695. Or call 919/515-2454. 



Carlo Burgess 



22 JULY/AUGUST 1994 



