Evaluation of Au to mated Aer ation Con trol in Shrimp Ponds

Abstract

The fea si bil ity and en ergy ef fi ciency of man ag ing aer ation in shrimp cul ture ponds with au to mated aer a tion tech nol ogy were eval u ated. Nine 0.1-ha ponds at the Claude Peteet Mari cul ture Cen ter, Gulf Shores, Al a bama were stocked with white shrimp, Penaeus setiferus, at a rate of 42 post-lar vae/m 2. All ponds were equipped with one 1-hp (7.1 kW aer a tion/ha) as pi ra tor pump aer a tors that were ac ti vated man ually, with tim ers, or with au to mated ox y gen sens ing de vices. Au to mated aer a tion was ini ti ated when dis solved ox y gen (DO) con cen tra tion dropped be low 3.2 mg/L (45% sat u ra tion) and ter mi nated when DO con cen tra tion rose above 4.2 mg/L. Timers were pre-set to ini ti ate aer a tion af ter nightfall when DO con cen tra tion fell be low 3.2 mg/L. Man ual op er a tion of aer a tion in volved ac ti vat ing aer a tors at sun down and ter mi nat ing op er ation at about 0800. At har vest there were no sig nif i cant dif fer ences among treat ments for gross shrimp yield, mean weight or sur vival (P > 0.05). Mean power con sump tion, mea sured in ki lo watt-hours, was signif i cantly dif fer ent among treat ments (P > 0.05). Au to mated aer a tion con trol ponds used 62% less power than timer-op er ated ponds and 80% less power than man u ally op er ated ponds. Timed op er a tion of aer a tors used 42% less power than man u ally op er ated treat ments. The au to mated con trol sys tem and timer sys tem re duced power costs over man ual op era tions. The au to mated sys tem pro vided the pro ducer with real-time infor ma tion about DO and tem per a ture reg i mens. Un der more in ten sive sys tems as aer a tion needs in crease, ex pected en ergy sav ings from automated con trol would likely de crease. Ini ti a tion of aer a tion by tim ers is a good, low-cost al ter na tive to au to mated con trols but with out the ben e fits of au to mated mea sure ment and real-time view ing of DO.