Management applications of genetic structure of anadromous sturgeon populations in the Lower Danube River (LDR), Romania

During the last decades, the over-exploitation of sturgeon stocks for caviar production simultaneously with severe habitat deteriorations has led to drastic declines in the natural populations of the Danube River. As a result of (i) decrease of sturgeon catches from 37.5 tons in year 2002 to 11.8 tons in year 2005, (ii) disrupted age class structure of sturgeon adult cohorts in years 2003 and 2004, and (iii) lack or low recruitment in the period 2001 – 2004, in 2005 the Romanian Government started the Supportive Stocking Program of Lower Danube River with hatchery-produced young sturgeons in Romania. Subsequently, in 2006 the commercial sturgeon fishing in Romania was banned for a 10-year period. Genetic investigations were undertaken as an attempt to assess the genetic variability of the sturgeon brood fish, captured from the wild, used in two aquaculture facilities in Romania for obtaining juveniles for supportive stocking of LDR with young sturgeons produced by artificial propagation in year 2007. Our data indicate strong genetic diversity in case of stellate sturgeon and lack of diversity within the batch of beluga sturgeon brood fish captured in 2007, analyzed in the current study. Specific measures that could improve the management plan of sturgeon brood fish in the Romanian part of LDR in the light of recent FAO guidelines regarding the sturgeon hatchery practices and management for release were suggested