IUU fishing in the Caspian Sea threatens the sturgeon populations

IUU Fishing in the Caspian Sea threatens the sturgeon populations

During the Panel Discussion the 8th International Symposium on Sturgeons (ISS 8) held in Vienna  (Austria) in September 2017, various critical conservation issues on the highly endangered sturgeons have been discussed. During the Panel Discussion in Vienna participants from the Caspian range states have raised the issue of the ineffectiveness of the measures taken to combat illegal harvest and it was emphasized that the insufficient enforcement will lead to the extinction of the species in question in the near future considering the current population trends. 

As was shown in 2012 by Ye and Valbo-Jörgensen (2012) already the recovery of the stellate sturgeon population in the Caspian Sea depends upon the elimination of IUU fishing which was considered the main driver or the ongoing decline of the species. This was determined in a “Depletion-Based Stock Reduction Analysis”. The authors concluded that according to the model output population recovery to a Biomass level of Maximum Sustainable Yield (MSY) would take until 2035 (50% confidence interval between 2026 and 2058) with all removals of fish being  immediately stopped.  Supportive stocking at a level as observed in 2010 would shorten the timespan to reach this level of Biomass by only five years. If IUU fishing continues the population would never be able to recover, the authors concluded.

A recent study in the Northern Caspian Sea by Ermolin & Svolkinas (2018), carried out a quantitative assessment of sturgeon catches and related Caspian seals’ by-catches of the illegal sturgeon fishery in the region of Dagestan and the Volga River Delta in Russia. Based upon semi structured interviews, direct observations and informal conversations the study concludes that both IUU sturgeon catch and the rate of seals-bycatch have not undergone any significant change since 2013. 


As such, it remains to conclude that significant efforts and a drastic change in enforcement activities are urgently required to prevent the extinction of sturgeons and other emblematic animals form the Caspian Sea! A joint Action Plan of the range states with legally binding activities has to be put in place that also addresses the livelihood issues of the local inhabitants (e.g. fishermen) to ensure that the unique Caspian Sea fauna has a chance to recover. 

Unfortunately, the situation does not differ much from that in the Black Sea, where catches of sturgeons are not effectively prevented and stringent enforcement measures in wide areas are lacking. The topics to be covered in an effective conservation strategy were outlined already in the RAMSAR DECLARATION (Rosenthal et al. 2005). 


Since long lead times are required for effective protection there must be a paradigm-change to overcome the presently insufficient support for actions in the range states. The lack of solid commitment adversely affects any targets set under international agreements. It becomes high time for the policy level to accept their responsibility for the loss of biodiversity and instead of half-hearted and mislead counter-measures and disappointing compromises when it comes to identify and allocate the required resources.



Ermolin, I.; Svolkinas, L. (2018) Assessment of the sturgeon catches and seal bycatches in an IUU fishery in the Caspian Sea. Marine Policy 87 (2018) 284–290. Available as preprint.


Rosenthal, H.; Pourkazemi, M., Bruch, R.M. (2005). The 5th International Symposium on Sturgeons, a conference e with major emphasis on conservation, environmental mitigation and sustainable use of the sturgeon resources. JAI 22(Supplement  1): 1-5.


Ye, Y; Valbo-Jørgensen, J.  (2012) Effects of IUU fishing and stock enhancement on and restoration strategies for the stellate sturgeon fishery in the Caspian Sea. Fisheries Research 131– 133 (2012) 21– 29