Biomass management in recirculating aquaculture systems using queuing networks.

摘要

Queuing network contains a series of service facilities (in our case, culture tanks or ponds), at some or all of which, a customer (fish) must receive service; it is, therefore, necessary to study the entire network. A culture tank or pond can be seen as a queuing system in which neither a queue ("over-holding" of fish in tank A before being moved to tank B), nor an idle pond is allowed, and arrival and departure rates are equal. The entire farm can be seen as a queuing network. A queuing model for optimizing the management parameters of a recirculating aquaculture system was developed. The model validity was statistically tested and was not rejected within the 95% confidence level, therefore, the model can be useful for both research and practical applications. The model aims to optimize: (1) the system layout, (2) the fish batch arrival frequency, (3) the number of fingerlings in a batch, (4) the number of days in each culture tank, and (5) grading criteria along the production lines. Under our local farm conditions we found that: the "2, 4, 8 layout" was a superior layout; the optimal operating parameters were: arrival of a batch every 36 days; 72 days at the nursery stage (up to 25 g); followed by 144 days (up to 200 g) at each successive growth phase. The optimal values maintain biomass density criterion of 80 kg m-3 and tank utilization criterion of never below 99%..