Using sun to stretch 

 The aquaculture season 



The problem : developing a year-round 

 aquaculture industry based on species that are 

 feasible and economical to grow 



Aquaculture, like farming, is a seasonal business in 

 North Carolina. But if year-round fish farming were 

 possible, the way would be open for a new aquaculture 

 industry here. 



Although the state has numerous sites where aquatic 

 farms could locate, so far only a limited amount of 

 private capital has been invested in aquaculture. With a 

 growing-season of only seven to eight months in outdoor 

 pools and ponds, aquaculturists face the possibility of 

 shutting down during the winter months. Moving culture 

 operations inside is one solution but the cost of heating 

 large volumes of water is generally prohibitive. 



And, not all species are economical to culture. 

 Aquaculturists need to know what species to culture and 

 how to produce those species with the lowest possible 

 costs. 



The research: studies into developing a passive 

 solar greenhouse for year-round culture, develop- 

 ing hardier species of fish for culture and creating 

 low-cost nutritional feeds for fish 



Because of the advantage of culturing fish year-round, 

 Sea Grant is developing a passive solar greenhouse that 

 will store the heat it collects during the day. "We want to 

 demonstrate that it will work and that we can have year- 

 round aquaculture in a temperate area like North 

 Carolina," says Ron Hodson, project director. 



Herbert Eckerlin will design and construct the 

 greenhouse at the Sea Grant Aquaculture Research and 

 Demonstration Center near Aurora, N. C. 



Since water serves as the main heat sink for the 

 greenhouse, Albert Rubin will design a recirculation 

 system to maintain water quality and to reduce heat loss. 

 Once the greenhouse is completed, Sea Grant will stock it 

 with striped bass hybrids or American eels to test its ef- 

 ficiency. Larry Giardina will provide advice for making 

 an economic analysis for the greenhouse. 



But, even a greenhouse isn't enough to make 

 aquaculture into an industry. Now, you need a crop. This 

 year, Howard Kerby and Mel Huish continue their work 

 with a striped bass hybrid. The striped bass is a prized 

 sport fish as well as a highly desirable commercial 

 species, but its populations have declined in recent years. 

 Previous studies showed the hybrids were hardier than 



the striped bass and raised the possibility of growing the 

 fish for commercial sale. 



The establishment of an aquaculture industry will also 

 depend on a low-cost nutritional feed for the fish. Margie 

 Gallagher will study the effects of protein-energy ratios 

 in the diets of cultured fish. By finding out what kind of 

 use the fish make of their food, Gallagher will determine 

 which foods can best support the growth of fish raised 

 commercially. 



The researchers: 



Ronald Hodson, Associate Director, UNC Sea Grant 



College Program 

 Albert Rubin, Department of Biological and Agricultural 



Engineering, North Carolina State University 

 Larry Giardina, Marine Advisory Services agent, UNC 



Sea Grant College Program 

 Howard Kerby, Department of Zoology, North Carolina 



State University 

 Melvin Huish, Department of Zoology, North Carolina 



State University 

 Margie Gallagher, Department of Home Economics and 



the Institute for Coastal and Marine Resources, East 



Carolina University 



Photo by Howard Kerby 



Curry Woods samples striped-bass hybrids in 

 pools at Aurora lab 



