Review of Bycatch Prevention and Mitigation Measures for Sturgeons

Produced with contributions from a working group on sturgeon bycatch in the frame of the EU Service Contract 09.0201/2022/885601/SER/D.3:

英语. The eight native sturgeons found in Europe are under massive threat of extinction. Anthropogenic pressures such as historic overexploitation and in some regionscontinued illegal fishing are primary reasons steep population declines. Damming, navigation, water abstraction, pollution and climate change also continue to impact thesuitability of their habitats. Historically, the presence of sturgeon has been documented so far in at least 78 river systems throughout the European continent but today theirpresence is limited to approximately 15 river systems with almost all populations depending on active recovery measures. Bycatch of sturgeon in a variety of marine,estuarine and freshwater fisheries poses a significant and so far often neglected threat to the recovery of critically endangered populations in Europe, as it removes rareindividuals from already very small remaining populations. This impact is especially pronounced in late maturing ad long lived species such as sturgeons while the exactdimension of the impact is unknown due to the fact that, similar to other protected and endangered species, the real numbers of individual sturgeons accidentally caught inthe diverse fisheries and their fate remains unknown. Despite existing obligations under the Habitats Directive to establish a system to monitor the incidental capture andkilling of the animal species listed in Annex IV, there are no official records on accidental captures available. Voluntary declarations by fishers that are collected in thedifferent sturgeon recovery projects at best provide patchy data and are known to massively underestimate the extent of the impact. In the frame of the EC Service Contract(09.0201/2022/885601/SER/D.3 “Supporting Conservation and Protection Actions to implement the Pan-European Action Plan for Sturgeons”), this report summarizes theavailable information on sturgeon bycatch in Europe supplemented by experience from North-America. Thereby, it contributes to the implementation of the PANEUAP aiming to “reduce accidental removal to levels allowing population recovery” (Result 1.2). It furthermore, outlines available approaches at hand for the prevention, themitigation or the improved knowledge base on the impact of commercial and recreational fisheries. Among the options discussed are the reduction of fishing pressurethrough temporal or spatial closures, gear alterations, technical surveillance systems or awareness raising and involvement of fishers.