An automated feeding system for intensive hatcheries

The continuous on-line meeting of metabolic demand via feed supply is an important factor for successful aquaculture. This factor is more acute for small larvae, which have a relatively high metabolism, implicating a long photophase and continuous feeding. Such requirements can not be easily met using classic manual feeding methods due to logistic problems. A computerized system has been developed for feed management in intensive hatcheries. The daily plankton requirements of larvae, organized in feeding tables together with a distribution pattern, was used for the development of the required hardware and software to control feeding. The system computes the food required (plankton organisms) and activates a peristaltic pump and solenoid valves for distribution to tanks. The system offers the option of feeding either according to tables or manually, depending on the concentration of plankton in the rearing tanks. Feeding is programmable for 24-h periods. A pilot scale application gave comparable results from a biological perspective and improved management when compared with standard methodologies. Four populations of sea bream (Sparus aurata) were reared with the pseudo-green water intensive method using the automated feeding system and two were reared using a standard technique, Larvae in both cases reached a total length of 10.73 +/- 0.77 mm in 30 days post hatching with survival varying between 41 and 51% without differences between the conditions tested. In terms of management, the labor requirement for feeding was reduced by 30-40% with the use of the automated feeding system while the utilization of Artemia nauplii was reduced by 40%. Feeding data as well as information concerning growth of the larvae and the evolution of the rearing were collected in a database. The system is compatible with other software packages for data collection and retrieval. (C) 2002 Elsevier Science B.V. All rights reserved.