Design and development of a geothermal temperature control system for broodstock management of channel catfish Ictalurus punctatus

Document Type

Article

Publication Date

11-1-2002

Abstract

A control system was designed to raise and maintain water temperatures within ∼0.03-ha earthen ponds to a range conducive for spawning (24-30°C) channel catfish Ictalurus punctatus. Heating was done during February 2001 to April 2001, when temperatures would have otherwise prohibited spawning (<24°C). Temperature was increased from ∼ 10°C (ambient) by ∼ 2°C per day, and maintained at ∼ 27°C, by the addition of geothermally warmed water (∼ 36°C). The control system substantially increased the controllability and precision of heating ponds compared to manual operation. Systems were designed to control sets of four ponds. In designing this control system, consideration of biological constraints was essential. Reproduction in channel catfish is most strongly influenced by temperature. Because cold fronts are common during the winter and early spring (January-March), it was essential to ensure that pond temperatures did not fall below the range for spawning. Constraints on the heating rate and temperature variability to maintain fish health and stimulate spawning behavior were considered. Components of the control system included temperature measurement devices (type-T thermocouples), a central electronic control unit, electronic switches and electrically actuated ball valves. In response to the temperature sensed by each thermocouple, the controller sent a message to close or open the valve. When the valve was opened, warm water was added to the pond to increase the average pond temperature. Hardware and algorithm design and initial system testing were the major components of this project. The final design incorporated information on relevant biological parameters and safety features including peak pond temperature, independent aeration and water pressure control mechanisms. Initial results indicate successful control of this biological system, and ongoing studies suggest similar mechanisms may be used for additional control objectives. In particular, this system could be used to vary pond temperatures to study biological responses and to cool ponds by addition of well water during summer months. © 2002 Elsevier Science B.V. All rights reserved.

Publication Source (Journal or Book title)

Aquacultural Engineering

First Page

277

Last Page

289

This document is currently not available here.

Share

COinS