LARGE AND DEEP PERIALPINE LAKES Fish assemblages in deep Italian subalpine lakes: history and present status with an emphasis on non-native species Pietro Volta . Erik Jeppesen . Paolo Sala . Silvia Galafassi . Claudio Foglini . Cesare Puzzi . Ian J. Winfield Received: 10 July 2017 / Revised: 1 April 2018 / Accepted: 9 April 2018 Ó Springer International Publishing AG, part of Springer Nature 2018 Abstract We provide a comprehensive overview of the status of fish assemblages in eight Italian subalpine lakes using multiple data sources: historical records, standardised sampling and fishery catch statistics. Thirty-four fish species were recorded, twenty of which are native, seven introduced historically and another seven introduced recently. The number of fish species in individual lakes has increased by between 25 and 65% from 1855 to the present, with the increase being higher in the larger lakes. Non-native species contributed between 4.0 and 71.5% to standardised catches by numbers and between 4.8 and 65.1% by biomass. Roach Rutilus rutilus and pumpkinseed Lepomis gibbosus dominated electrofishing and ben- thic catches by number, while open-water catches were dominated by the coregonids European whitefish Coregonus lavaretus and gangfish Coregonus macrophthalmus. In terms of biomass, electrofishing catches were dominated by crucian carp Carassius carassius, largemouth bass Micropterus salmoides and wels catfish Silurus glanis, benthic catches were dominated by roach, European whitefish and crucian carp, and open-water catches by coregonids. Com- mercial fisheries are important ecosystem services provided by subalpine lakes, with their harvests now dominated by non-native species. To deliver effective biodiversity conservation and ecosystem services provision, the prioritisation of targets and interven- tions of management of non-native species is needed. Guest editors: Nico Salmaso, Orlane Anneville, Dietmar Straile & Pierluigi Viaroli / Large and deep perialpine lakes: ecological functions and resource management Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10750-018-3621-0) con- tains supplementary material, which is available to authorized users. P. Volta (&) Á P. Sala Á S. Galafassi Á C. Foglini CNR-Institute of Ecosystem Study, L.go Tonolli 50, 28922 Verbania Pallanza, Italy e-mail: p.volta@ise.cnr.it E. Jeppesen Department of Bioscience, Aarhus University, Vejlsøvej 25, 8600 Silkeborg, Denmark E. Jeppesen Sino Danish Centre for Education and Research, Beijing, China C. Puzzi GRAIA srl – Gestione e Ricerca Ambientale Ittica Acque, Via Repubblica, 1, 21020 Varano Borghi, Varese, Italy I. J. Winfield Lake Ecosystems Group, Centre for Ecology & Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, Lancashire LA1 4AP, UK 123 Hydrobiologia https://doi.org/10.1007/s10750-018-3621-0