Shellfish production conditions have generally become more difficult due to disturbance of the environment, such as through climate change and pollution, competition for available space with other activities, such as tourism and coastal area protection and infectious diseases, which cause serious mortalities, especially in Pacific oyster, flat oyster and Manila clam.

To maintain shellfish production, which is an important industry on the coast, at its present level, a vital element is a supply of good quality seed in sufficient quantity and at the correct periods of the year.  Because seed capture or collection in the wild has become unreliable, bivalve mollusc hatchery-nurseries have developed in several European countries. However, their methods often remain empirical and their output low, except for the Pacific oyster. Knowledge on hatchery procedures is still only partial for most species. This hatchery production is not intended to replace traditional methods of seed supply, but can complement it and should provide the means to select bivalve resistant to infectious diseases in the future.

The objectives of the REPROSEED program are to gain new knowledge on shellfish physiology though the optimisation of rearing techniques and to carry out technology transfer to the industry.