AN INTEGRATED SYSTEM FOR MICROALGAL AND NURSERY SEED CLAM CULTURE
T.J. Pfeiffer, K.A. Rusch-2000
Aquacultural Engineering, 24 (1): 15-31
Abstract:
A PC-controlled integrated system for the production of algae and culture of northern quahog seed was constructed. The diatom, Chaetoceros muelleri, was cultured in covered 550 l tanks. The harvested alga was the food source for the land-based nursery seed clam system. The nursery clam system consisted of six culture units constructed of clear PVC tubing, a 400 l feed reservoir, a solids separator, and a bead filter (0.03 m3). The culture units were 5 cm in diameter and 76 cm in height. The total system volume was 450 l and the recirculation flow rate was 40 lpm. Components of the computer control system include a laptop computer, a multiport connector, analog to digital converter (ADC) boards, and solid-state relays for each control output. Sampling, harvesting, refilling, and redosing of the algal chambers, seed clam feeding operations, cleaning of the seed bed by increased fluid flow, purging of the separator wastes, and backflushing of the bead filter were all computer controlled. The integrated system was tested using Mercenaria seed clams. The initial shell length of the seed clams were 2.5 (±0.5) mm, and were stocked at a density of 3.0 g whole wet weight cm-2. During 83 days of culture using the system the seed clams were sorted twice and reached an average shell length of 7.9 (±0.8) mm. The percentage of survival percent was determined at different stages of growth during the culture period and ranged from 67.3 to 88.0%.
(Shellfish Aquaculture Laboratory, University of Georgia Marine
Extension Service, 20 Ocean Science Circle, Savannah, GA 31411-1011, USA)
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