Global population structure of the great sturgeon (Huso huso) in the southern part of the Caspian Sea with emphasis on the Golestan Province

Report of the project entitled "determination of the global population structure of the great sturgeon (Huso huso) with emphasis on the Golestan Province" is in front of your attention. Outcome is the results of study on the samples collected from the total catch in the landing sites namely Bandar-e-Anzali, Babolsar, and Ashooradeh, in the three Northern provinces. 224 specimens were collected according to the sampling manual during the fishing seasons in 2005 and 2006. Three methods were applied in this study to find out the population structure of the great sturgeon in the southern Caspian Sea. These were as follows: Morpho-metric meristic Population dynamics Population genetics (microsatellite loci) Results indicate that the range of different age groups of the great sturgeon in the Golestan Province is larger than the other two provinces. Results show that the older age groups are found in the samples from the Golestan Province rather than the other two provinces. Results demonstrate that the sample size for the two methods (morpho-metric meristic and population dynamics) is not enough. In order to obtain precise results with less uncertainty one needs to collect more specimens. Therefore, according to the few number of the great sturgeon in the total sturgeon landing, it is recommended that researchers apply methods other than the two methods which are mentioned above in order to make sure that the results are most reliable. Population genetics methods including microsatellite loci are among the methods which could produce good results with minimum bias in this regard. Results indicate that there are two distinguishable populations of the great sturgeon (Huso huso) in the southern part of the Caspian Sea off the shores of the three Northern provinces. Results also show that these two populations are scattered in the two east end (Golestan Province) and west end (Guilan Province) of the southern Caspian Sea. The two populations have overlapped each other in the Mazandaran Province