Identification and tracking of sturgeons and paddlefish products in trade: Implications for trade control and biodiversity management

Despite strict protection of natural populations and CITES restrictions on international trade of caviar, sturgeons are increasingly at risk of extinction. The latest assessment released in July 2022 by the IUCN confirms sturgeons and paddlefish as the most endangered group of species on the planet. In this context, poaching and the illegal trade of caviar and meat have a significant weight and it is, therefore, necessary to support control activities by identifying diagnostic and reliable methods for the identification of species, interspecific hybrids, aquaculture or natural origin and geographical provenance of commercial samples. The technical approaches used for this purpose now include biochemical, isotopic, and genetic marker analyses, and are constantly evolving with remarkable developments proposed in recent years. Among these, particularly relevant are the numerous nuclear genetic markers, which allow the identification not only of pure sturgeon species but also of interspecific hybrids and the approaches based on the analysis of fatty acids which allow to distinguish feed-fed animals from fed with natural food. Additionally, the use of multi-isotopic fingerprint analyzes to determine the geographical area of origin is rapidly developing and is proving to be extremely useful for commercial controls and for the protection of natural sturgeon populations.This synthesis arises from the need of providing an exhaustive picture of the available technical approaches and to evaluate their potential and limits, focusing mainly on the innovations proposed in the last 10 years which have significantly improved our diagnostic power.