The power of integrating genetic and otolith analytical approaches into the spatial management of exploited marine fishes

Marine exploited populations exhibit various degrees of discreteness, ranging from historical evolutionary to contemporary ecological levels of differentiation. An integrated approach combining complementary population discrimination tools such as otolith microchemistry and genetics may capitalize on these different time scales to improve the discrimination and traceability power in management applications. Here, I discuss the most recent integrated results obtained from genetic markers (microsatellites and SNPs) and otoliths (microchemistry and shape data) on juvenile/adult sole (Solea solea) populations in the North-East Atlantic Ocean. While genetic markers provide a clear regional differentiation and local adaptation pattern, otoliths data often provide an improved small scale geographical resolution. Our results highlight the power of a multi-marker approach depending on the required spatial resolution scale in future management scenarios. Monitoring efficiently the resilience of marine harvested populations hence requires interdisciplinarity in research priorities, covering both the evolutionary and ecological components of population connectivity. Such information is pivotal to reliably develop, validate and later apply integrated traceability tools for fisheries enforcement.