Project summary
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 research focuses on with the development of a new lighting technology based on Cold Cathode Light Tubes, and then appropriate lighting protocols for the systems application in cod mariculture. 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) setup [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 in relation to lighting regimes. As a whole this proposal represents a number of key fundamental developments.
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 research focuses on with the development of a new lighting technology based on Cold Cathode Light Tubes, and then appropriate lighting protocols for the systems application in cod mariculture. 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) setup [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 in relation to lighting regimes. As a whole this proposal represents a number of key fundamental developments.
