From a quick Google, the import of the two manatees by DWA was in 1997 when they were about a year old, so they (or at least the surviving one if the other has since died) would be about 28 years old now. I couldn't find anything on reproductive senility in manatees, other than some statements that it isn't known, but given that they can live much longer than 30 years old I doubt the DWA one(s) would be too old to breed.
