The impact of lighting conditions on growth and development of larval haddock (Melanogrammus aeglefinus) in culture

Development of new candidate species for mariculture improves the stability, growth, and global competitiveness of the Canadian aquaculture industry. Faced with the challenge of maximizing production to meet projected demand, aquaculture scientists have extensively studied environmental effects on growth and survival of cultured fish species. Understanding the constraints imposed on developing larvae by these physical factors is critical for creating protocols to optimize survival and growth.; Haddock culture has attracted attention along the East Coast of North America because of the species' existing markets and potential for high product value. Research efforts, particularly within New Brunswick, have been directed towards developing standardized protocols for haddock culture, especially with respect to the role of physical parameters during early life history stages.; Light has been shown to be an important ecological factor for a number of commercially important fish, influencing development and behaviours from egg to sexually mature adult. In this thesis, a series of studies was employed to determine the impact of different physical properties of light [quantity (intensity), quality (spectral composition), and periodicity] on development of haddock embryos, and on growth, survival and first feeding of haddock larvae.; Significant effects of light on the early life history stages of haddock were shown. However, the effects varied with developmental stage. Time to hatch and size-at-hatch of embryos was influenced by photoperiod. Light intensity and its interaction with tank colour significantly influenced growth and survival of larvae. Successful initiation of first feeding by larvae was greatest under a blue light comparable to that encountered in the ocean. Differences both between the light requirements of larval haddock versus other teleosts, and between those of the different early life history stages of haddock can be explained with reference to the species' natural ecology in the open ocean nursery waters, and the visual conditions within this environment.; This thesis serves as a contribution to the advancement of the aquaculture of haddock in Atlantic Canada.