It is not out of the question that by-catches made in river, estuary or estuary mouth contribute to the supply of mature spawners that may be used in a reproduction operation under controlled conditions.  It is therefore necessary that logistical means be set up in order to ensure the safe transfer of the individuals to the Cemagref or IGB facilities.  This goes from informing fishermen, who might catch a sturgeon, to the availability of means by which sturgeons may be recovered.  Thought should be given as to when and where the spawners should be taken and the characteristics of the specimens (size, sex) that could be used in this operation.