Dear MARMAM subscribers, We are pleased to announce the publication of the following paper in "Ecological Indicators": Ruth Esteban, Phililppe Verborgh, Pauline Gauffier, Joan Giménez, Vidal Martin, Mónica Pérez, Marisa Tejedor, Javier Almunia, Paul D. Jepson, Susana García-Tíscar, Lance G. Barret-Lennard, Christophe Guinet, Andrew D. Foote, Renaud de Stephanis. *Using a multi-disciplinary approach to identify a critically endangered killer whale management unit.* *Abstract* A key goal for wildlife managers is identifying discrete, demographically independent conservation units.Previous genetic work assigned killer whales that occur seasonally in the Strait of Gibraltar (SoG) andkiller whales sampled off the Canary Islands (CI) to the same population. Here we present new analy-ses of photo-identification and individual genotypes to assess the level of contemporary gene flow andmigration between study areas, and analyses of biomarkers to assess ecological differences. We identi-fied 47 different individuals from 5 pods in the SoG and 16 individuals in the CI, with no matches foundbetween the areas. Mitochondrial DNA control region haplotype was shared by all individuals sampledwithin each pod, suggesting that pods have a matrifocal social structure typical of this species, whilstthe lack of shared mitogenome haplotypes between the CI and SoG individuals suggests that there waslittle or no female migration between groups. Kinship analysis detected no close kin between CI and SoGindividuals, and low to zero contemporary gene flow. Isotopic values and organochlorine pollutant loadsalso suggest ecological differences between study areas. We further found that one individual from a podwithin the SoG not seen in association with the other four pods and identified as belonging to a poten-tial migrant lineage by genetic analyses, had intermediate isotopic values and contaminant between thetwo study areas. Overall our results suggest a complex pattern of social and genetic structuring corre-lated with ecological variation. Consequently at least CI and SoG should be considered as two differentmanagement units. Understanding this complexity appears to be an important consideration when mon-itoring and understanding the viability of these management units. Understand the viability will helpthe conservation of these threatened management units. You can downloaded at this link: http://www.sciencedirect.com/science/article/pii/S1470160X16000571 Kind Regards, Ruth Esteban Ruth Esteban, PhD. CIRCE ( ​​ Conservation Information and Research on Cetaceans) C/Cabeza de Manzaneda 3 C.P. Pelayo-Algeciras (Cádiz) Spain +34675837508