Stocking Efficiency of the Sterlet (Acipenser ruthenus, Linneaus 1758) in the Slovak – Hungarian Danube Stretch

Kubala, Maroš; Farský, Martin; Pekárik, Ladislav

doi:10.31262/2585-8556/2017/1/1/25-31

Cited by 2 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A sample of the stocked individuals consisting of 1270 individuals was tagged with FLOY tags during 2013-2016. The ratio of recaptures was very low, two individuals were recaptured few weeks after stocking and one tag was found in the stomach of the wels (Silurus glanis, L.) about 1 month after stocking (Kubala et al, 2017). Furthermore, ageing of the sterlet population seems apparent in recent years.…”

Section: Introductionmentioning

confidence: 99%

Current stocking program of the sterlet (Acipenser ruthenus, L.) can negatively shape its genetic variability in the Middle Danube

Pekárik

Čiamporová‐Zaťovičová²,

Arendt³

et al. 2019

Knowl. Manag. Aquat. Ecosyst.

Self Cite

View full text Add to dashboard Cite

The Danube River was originally inhabited by six native sturgeon species, but currently, the sterlet (Acipenser ruthenus L.) is the only native sturgeon species still occupying the Slovak–Hungarian stretch of the Middle Danube. All sturgeon species are facing extinction, suffering from overfishing, water pollution, illegal fishing, poaching or other negative impacts. Urgent and proper actions are needed to prevent their extinction, and evaluating its genetic diversity is one of the essential tools of conservation programs. Since the management actions are primarily local in nature, we first focused on comparing and analysing local sources of fish for population recovery and natural (wild) population in the adjacent stretch of the Danube River. We used 2 fragments of mitochondrial DNA and 12 microsatellites to analyse the genotype of the three groups of sterlets, i.e. wild, broodstock and stocked individuals from Slovak part of the Danube. Mitochondrial markers of all groups were diversified similarly to populations from other parts of the Danube. This confirmed that broodstock and stocked fish belong to the original Danube population. Microsatellites revealed very similar patterns among groups compared, but we detected possible negative trends reflected in losing polymorphism in a few loci in broodstock and stocked individuals.

show abstract

Section: Introductionmentioning

confidence: 99%

Current stocking program of the sterlet (Acipenser ruthenus, L.) can negatively shape its genetic variability in the Middle Danube

Pekárik

Čiamporová‐Zaťovičová²,

Arendt³

et al. 2019

Knowl. Manag. Aquat. Ecosyst.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The restocking efficiency is usually drastically low. For example, of 1,270 tagged sterlet released in 2013–2016 in Slovakia only two were recaptured (Kubala, Farský & Pekárik, 2017). Although these individuals were in better condition than when released, the number is still extremely low.…”

Section: Discussionmentioning

confidence: 99%

“…Catfish ( Silurus glanis , Linnaeus 1758) were identified, however, as species with the highest risk of predation for young sturgeons. Interestingly, an angler reported finding a tag from a stocked sterlet found in the intestines of a captured catfish in Slovakia, suggesting predation (Kubala, Farský & Pekárik, 2017). Restocking is usually carried out by releasing high numbers of fish into one area, which might increase the risk of predation, thus decreasing the effectiveness of the action.…”

Section: Discussionmentioning

confidence: 99%

Bayesian modelling suggests that the sterlet (Acipenser ruthenus, Linnaeus 1758) population is ageing in the middle Danube River

Kubala

Farský²,

Krajč³

et al. 2021

Aquatic Conservation

Self Cite

View full text Add to dashboard Cite

In the past, sturgeons played an important role in commercial and recreational fisheries in the Danube River and its tributaries. Human impacts in the Danube River Basin coupled with exploitation of sturgeon stocks led to all species being either locally extinct, critically endangered or of unknown status. Sterlet (Acipenser ruthenus, Linnaeus 1758) is the last known sturgeon species occurring in the upper and middle Danube; however, the population of this species is considered unbalanced and decreasing since the beginning of the twenty‐first century. The decline of sturgeon stocks has been noted before owing to their economic importance. With commercial fisheries being forbidden in the Slovak section of the Danube River, there is generally no information available about the status of what is considered a local population. Databases containing recreational catch of sterlet (2003–2018) and historical records of commercial harvest (1961–1990) were used to describe the trend in the weight and number of sterlet caught over the following years. Modelling indicated that the number of fish caught each year appears to be lower, while the average weight of each individual is increasing. This might suggest that the population is ageing. Although older individuals can contribute a great deal more to spawning because they produce a greater number of eggs, several problems are apparent. The number of spawners might be decreasing as a result of bycatch or fishing, their ability to spawn might be obstructed, or annual recruitment may fail owing to unpredictable events. Although restocking programmes are in place to help maintain the sterlet population in the Danube River, their efficiency seems to be drastically low. In fact, restocking could be of little value unless studies on the availability of key habitats are conducted and their protection and restoration are ensured.

show abstract

Stocking Efficiency of the Sterlet (Acipenser ruthenus, Linneaus 1758) in the Slovak – Hungarian Danube Stretch

Cited by 2 publications

References 0 publications

Current stocking program of the sterlet (Acipenser ruthenus, L.) can negatively shape its genetic variability in the Middle Danube

Current stocking program of the sterlet (Acipenser ruthenus, L.) can negatively shape its genetic variability in the Middle Danube

Bayesian modelling suggests that the sterlet (Acipenser ruthenus, Linnaeus 1758) population is ageing in the middle Danube River

Contact Info

Product

Resources

About