Session B8: Swimming Behaviour of Beluga and Stellate Sturgeons During Their Migration in the Lower Danube River

Abstract: The Lower Danube River (LDR) still supports three naturally self-sustaining species of anadromous sturgeons. Beluga sturgeons (Huso huso) and stellate sturgeons (A. stellatus) are still common while Russian sturgeons (Acipenser gueldenstaedti) became very rare. Studying their swimming behaviour is essential for understanding (i) the impact of construction works aiming to improve conditions for navigation; (ii) sturgeon behaviour in relation to Iron Gate hydropower and navigation systems; (iii) behaviour of young sturgeons during downstream migration towards the Black Sea. A significant number of wild adult sturgeons (N= 103; 39 beluga, 1 Russian and 63 stellate) was implanted with acoustic transmitters, with depth and temperature sensors, and their movements were tracked using arrays of submerged automatic receivers installed in the LDR (R Km 60 – 863) during 2009 – 2014. For some of these fish additional swimming depth data were obtained by manual tracking. Wild born young of the year (YOY) beluga sturgeons (N=27) were captured in the LDR (R Km 123), implanted with acoustic transmitters and released during routine monitoring (June 2010). YOY beluga sturgeons of hatchery origin (N=33) were implanted with acoustic transmitters and stocked in the LDR at R Km 300 and R Km 102 (August 2010). Their movements were tracked and recorded by arrays of submerged acoustic receivers installed on the main Danube (R Km 101) and the three branches of the delta. This paper analyses for the first time on the LDR consistent data (over 70,000 recordings) on swimming speed (upstream and downstream) and swimming depth behaviour of adult sturgeons (beluga and stellate), during spring and autumn migration season, and YOY beluga sturgeons of wild and hatchery origin

Long Distance Migration of Beluga (Huso huso) and Stellate Sturgeon (Acipenser stellatus) in Lower Danube River in Relation with Iron Gate II Dam

Construction of the dams in Lower Danube River (LDR- rkm 0 Sulina – rkm 1075 Baziasi) without fish passages, as well as illegal fishery and river bottom modification due to navigation had negative impact on sturgeon’s populations. Beluga Sturgeon, Stellate Sturgeon and Russian Sturgeon still migrate to spawn in LDR but there is lack of information relating to sturgeons long distance migration in this area. Tagging with Vemco V16 TP acoustic tags, equipped with temperature and depth sensors involved 36 adult Beluga and 44 Stellate Sturgeons provide new data about sturgeon migration. Their migrations are monitored by VR2W receivers, deployed on between rkm 71 and rkm 864. Analysis of data showed that 17% of Beluga and 30% of Stellate Sturgeon never recorded and 30% and 11% of Beluga and Stellate Sturgeon recorded in period more than 30 days after tagging. Only 5% of Beluga and 7% of Stellate Sturgeon have been recorded after a period of more than 1 year. During 2013-2016 4 adult Beluga and 1 adult Stellate Sturgeon were recorded in the IGII Dam area. Results of this investigation showed that sturgeons still approached the IG2 dam and construction of fish passage on this dam is needed

The analyse of the antioxidant effect of natural peloidotherapy in aging process

Medical research has developed remarkably in recent years, including the involvement of the glutathione peroxidase (GPx) family of enzymes in the course of human aging, with numerous clinical studies published in the literature reporting this particular fact. Thus, mud therapy and its effect on biological aging have been represented in papers that have been published to date. Papers published in the literature analyzing GPx vari-ation during sapropelic mud therapy suggest the beneficial effect of this family of en-zymes in diseases with an important inflammatory component, mainly monitored in patients with osteoarthritis. This study investigated the effects of sapropelic mud treat-ment on GPx values in patients receiving treatment with sapropelic mud at the Balneal and Rehabilitation Sanatorium of Techirghiol, Romania. We included 52 patients, split into two groups, who received treatment with cold mud baths and warm mud baths. Values close to statistical significance were found in patients who received treatment with cold mud baths in terms of mean GPx values at the four-time points studied. Fur-ther studies evaluating GPx in patients receiving sapropelic mud treatment are needed

Researches considering the effect of the gradual insertion of fodder in alimentation for the growth rhythm of Siberian sturgeon larvae (Acipenser baerii – Brandt, 1869) reared in superintensive system

The experiment was made inside of private sturgeon rearing farm S.C. “Beluga Farm Group” S.R.L. from Calarasi County. The rearing system is flow-through and is emplaced into an enclosure as halltype. Sturgeon larvae were reared in spun glass troughs of a 0.167 m3 capacity. Experiment duration was 20 days. Biological material, Siberian sturgeon larvae (Acipenser baerii – Brandt, 1869), was gained by artificial breeding of breeders imported from Germany. The experiment was going off with two variants and three replications each. The rearing density was the same in both experimental variants, 500 ex/tank respectively. The diet of larvae from each variant was different as follows: in variant I, the larvae were fed exclusively on live diet represented by Tubifex species; in variant II, the larvae were gradually carried over from a diet consisting of Tubifex species to a diet represented only by Perla Larva fodder with a protean content of 62.0 %. On both experimental variants, fed delivery was achieved in the same way, namely the same number of daily intakes, dispensed at the same time. At the end of theexperiment, the results were as follows: in variant I, the survival rate was 75 % and the final average body mass of larvae 2.69 g/ex, in variant II, the survival rate was 66 % and the final average body mass2.38 g/ex

Studies Regarding the Biological Parameters of Azov Shad (Alosa tanaica, Grimm, 1901) from the Romanian Black Sea Coast

Azov shad (Alosa tanaica, Grimm 1901) is a marine anadromous species, which migrates for spawning from sea into fresh water lakes and rivers. It winters in the sea and appears close to shore in spring when the water temperature reaches the value of approximately 6 degrees Celsius. The paper presents the biological parameters such as length and weight class structure, age, sex ratio and degree of maturation of the commercial fish Azov shad belonging  to  the  family Clupeidae.  The  investigations were  performed  during  2014 on  fish  caught  along  the entire Romanian coast  from  Sulina  to  Vama Veche. The study of the behaviour of Azov shad (reproduction, migration, feeding) is important to understand the impact on populations and to find sustainable solutions to manage these aspects. The preference for certain areas of distribution, for feeding and breeding was determined by analysing samples collected by passive fishing (shad gillnets set in all fishing points across the Romanian Coast). The main aim of this research is to identify the current state of Azov shad population along the Black Sea Coast considering that its biology and conservation are less known