Cod held in intensive culture mature within 2 years from hatching loses somatic growth rate decreases condition deteriorate flesh composition and loses at least 25 of wet weight. A delay or cessation of maturation during on growing is therefore crucial for profitable farming. Seasonally changing day length photoperiod is the natural time keeping mechanism used by finfish from temperate latitudes to entrain a number of important physiological processes including sexual maturation and overlaying of artificial illumination on the natural day night cycle in day length masks this seasonally changing signal. Such techniques have been shown to successfully regulate maturation in a number of tank-based studies in Atlantic cod in which a complete cessation of maturation and up to a subsequent 60 improvement in growth have been observed.
When such test photoperiods are applied at a commercial scale in open floating cage systems it is believed that ambient light can has a major regulatory influence and as such the results reported have not been consistently reproducible. The current research proposal deals with a new lighting development Cold Cathode Light Tubes. This project intends to test and demonstrate the efficacy of a this technology with an improved light intensity output of 240 compared to the first generation systems and more importantly a production price estimated to be in the region of only 10 15 of a Light emitting diode LED set-up. The only possible comparable technology. This new technology will thus be tested in a range of commercial cod farms reflecting the diverse nature latitude and systems of the EU cod farming industry. A simple analytical maturation detection kit will be developed allowing real time detection of sexual maturation activity on farm. Also a comparison of standard manual assessment length weight and the use of passive measuring system for growth assessment and the development of a basic standardised flesh quality scheme.
Call for proposal
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