Introduction
Worldwide, several sturgeon species are facing the threat of becoming extinct in the wild, and in Europe some are only surviving because of the success of ongoing recovery programs that include last resort measures such as ex situ conservation. Ex situ conservation involves captive rearing and propagation under controlled conditions and can serve as a stop gap measure while other recovery actions are implemented. It is critical that these programs preserve the different components of genetic diversity, on the one hand the differentiation between populations, which could reflect adaptations to different environmental conditions, on the other hand, the genetic diversity within populations which represents their adaptive potential. This attention to the genetic integrity will increase the chances of long-term population persistence even after the cessation of ex situ measures.
Discussion
In many cases, small population sizes or ex situ programs that were initiated long after population declines began result in difficulties to meet genetic diversity goals. Accordingly, programs must ensure an approach that maximizes genetic outcomes, through the integration of all suitable resources. While Recommendation 22 of the Vienna Declaration on Global Sturgeon Conservation by global sturgeon experts (Rosenthal et al., eds. 2018) stated that “Commercial farms, culturing sturgeons for consumer markets, may be important partners in conservation programs to bridge the time-window until the required public infrastructure for ex situ conservation is in place...” it has become that, despite numerous biodiversity programs and funding tools, the implementation or long-term maintenance of such public facilities in Europe has not been feasible in most cases. It is therefore mandatory to search for practical alternatives for species recovery.
Several sturgeon species are in the unique condition that while being threatened in the wild, they are raised successfully and economically in large quantities in private companies. This opens opportunities to explore private-public partnerships for the benefit of these species at risk. In this presentation we will outline prerequisites to implement such collaborations as well as the limitations. This will include the importance of maintaining genetic differentiation and diversity of subpopulations; as well as the separation of commercial and conservation rearing facilities to prevent disease transfer and to meet the criteria for fitness for release of juveniles.
Outlook
In the Conservation Session, it is anticipated to build on the discussion that has started at the EAS 22 in Rimini in 2022. In order to guide the discussion to a target oriented output, it is foreseen to focus on the following questions in the round table discussion:
Reference
Rosenthal, H., Gessner, J. Bronzi, P. 2018. Vienna Declaration on Global Sturgeon Conservation, WWF and WSCS, Vienna and Neu Wulmstorf, 16 pp.