The National Institute for Research and Development inEnvironmental Protection Bucharest (INCDPM) attended between 10-15 of September 2017 at the 8th International Symposium on Sturgeon (ISS8) held at the University of Natural Resources and Life Sciences (BOKU), Vienna, Austria. This symposium has a history of 28 years being one of major importance, both in the number of participating countries (over 30 countries) and the novelty of addressed subjects.
The paper “Actual status, pressures and preserving perspectives of species of sturgeon on the Lower Danube” presented by team INCDPM started from the following hypothesis: If Lower Danube sturgeon species are endangered, there should be determined the real pressures that led to their actual status through intensifying monitoring actions and forming multidisciplinary international teams with open-minded researchers, not narrow”.. Thus, were presented the unique results obtained by INCDPM over the last six years of intensive monitoring using DKTB and DKMR-01T systems (internationally recognised) showing that on the lower Danube can be found only 4 species of sturgeon (beluga sturgeon , stellate sturgeon, sterlet sturgeon and russian sturgeon), the first three being in continuous decrease, and the fourth being threatened with critical extinction (as reported on the scale of extinction, Deak et al., 2017).
The research shows that the main pressures on sturgeon species are poaching, irrational fishing and hydrotechnical constructions. Thus, Dr. Eng. DEÁK György, general manager of INCDPM, stressed the attention to the following aspects:
- Nowadays, poaching is the most visible threat on the species of sturgeon from the Lower Danube – amplifyed by the lack of involvement of the regulator authority (National Agency for Fisheries and Aquaculture), which INCDPM seeks to quantify by ultrasonic tagging and to hamper by anti-poaching tagging and by cooperating with supervision and strength authorities of the Romanian state.
- Sturgeon have the ability to adapt to new conditions created by hydrotechnical constructions, if the longitudinal connectivity is not interrupted, a fact demonstrated by the case of the bottom sill built (up to level 0 MNC) on Bala branch wich sturgeon were able to pass (both during construction and after completion).
- Impact of the Iron Gates constructions is not as significant for the decline of sturgeon as is considered because: i) a drastic reduction of the sturgeon number occurred since 1940; ii) longitudinal connectivity have been interrupted (as INCDPM estimated was reduced by about 60% of the possible migration routes), but migratory species of sturgeon reproduced with higher frequency far downstream of the Iron Gates, thus, the few specimens for which migration was interrupted can find new breeding habitats.
It should be noted that specimens that arrived in southern Bavaria, Germany were very rare(Reinartz, 2002), but very large observation sustained by the INCDPM results regarding scarcity of specimens of Huso-huso caught and tagged (only 5% are larger than 2.5 m). INCDPM’s priority is finding the real causes that led to the decline of sturgeon in the Lower Danube since it public attracted attention that, opposite other researchers opinions, the causality of this disastrous aspect is not entirely due to Iron Gates because remains the question: Why starlet sturgeon (potamodromous) is missing upstream of the construction?, besides the fact that it was found a sturgeon population decline before the construction of Iron Gates.
The paper presented by INCDPM team was acknowledged by researchers from other countries (Great Britain, Georgia, Canada, USA, and Russia), this occasion fostering new collaboration opportunities for the conservation of the Lower Danube sturgeon species.