Seabass and gilthead seabream are the two marine fish species, which have characterized the development of marine aquaculture in the Mediterranean basin in the last two decades. The substantial increase in production levels of these two high value species has been possible thanks to the progressive improvement in the technologies involved in the production of fry in hatcheries. As a result of this technological progress more than one hundred hatcheries have been built in the Mediterranean basin, working on these and other similar species. At present the farmed production of these two species that is derived from hatchery produced fry is far greater than the supply coming from the wild. The development of these techniques, based originally on Japanese hatchery techniques has followed its own evolution and has resulted in what could be called a Mediterranean hatchery technology that is still evolving to provide higher quality animals and to reduce cost of production. This is a dynamic sector but it can be judged that it has reached a level of maturity that merits the production of a manual for hatchery personnel. The preparation of the manual has taken several years, also due to the progress of the sector that led to substantial revisions of sections. This has lengthened its preparation beyond what was originally expected. The manual is not intended to be the final word on hatchery production but rather a publication on how the industry produces in the late nineties. We preferred to include proven procedures rather than orient this publication to research on hatchery produced fry, as there is plenty of academic literature on this subject.The main advantages of these filters consist in the possibility of modifying the duration of the contact between water and bacteria colonizing the substrate, simply by changing the speed of the water flow. ... The bacterial film, which is not constantly submerged, is exposed to the air. ln this type of filter, water is well oxygenated, thus favouring the process of oxidation of ammonia and nitrites, the removal ofanbsp;...
|Title||:||Manual on Hatchery Production of Seabass and Gilthead Seabream|
|Author||:||Alessandro Moretti, Food and Agriculture Organization of the United Nations|
|Publisher||:||Food & Agriculture Org. - 2005|