Location and capture of suitable wild broodstock frequently is 

 difficult and expensive. Legal restrictions in many cases prevent 

 commercial fish farmers from capturing broodstock. In other cases, 

 permits or licenses are required. The aquaculturist usually has 

 little expertise in the use of hormones or manipulation of 

 temperature and light for controlled reproduction. The techniques 

 of seed production for some species are known, but a supply of seed 

 or broodstock may be unavailable. Ideally, domesticated broodstock 

 should be available for each cultured species. In addition, a 

 major problem in some species is the lack of immunological and 

 other procedures to prevent disease during the f ry-to-f ingerling 

 rearing period. Another problem is the cost and availability of 

 natural foods for those finfish that produce eggs and larvae for 

 which no adequate formulated feed exists. Solutions to these 

 problems are needed, since a dependable supply of seed and 

 fingerlings is vital to the operation of the industry. 



Predation and Mortality 



Predation is an especially serious problem in the culture of 

 various marine molluscs and some freshwater species. Lack of 

 suitable techniques for the control of predators represents a major 

 constraint to production. 



Mortality is also directly related to other factors such as poor 

 water quality, disease, and the lack of appropriate food, 

 particularly in larval stages. Water contaminated by various 

 chemicals and pesticides can also be a cause of death. 



Harvesting, Processing, and Distribution 



Technical knowledge in these areas is lacking for some species. 

 Even for some successfully cultured species, mechanized harvesting 

 methods have not been developed. Also, differential growth 

 necessitates harvesting larger animals without injuring the smaller 

 ones being kept for further growth. 



Technological advances must be made to improve water quality, 

 oxygen supply, water cooling, and waste removal in long-haul 

 trucks, ships, and planes, for the live-market trade. Also, there 

 is a need for improved flash-freezing and storage techniques to 

 lengthen shelf life. 



Product Quality Control 



Growing organisms in wastewater effluents and using nonregistered 

 drugs for disease control may contaminate the final product with 

 chemicals or harmful pathogens. 



Off-flavor is sometimes a problem with cultured products. This can 

 be caused by poorly formulated feeds, substandard water quality, 



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