title: Do small barriers affect the movement of freshwater fish by increasing residency?
abstract: River fragmentation due to artificial barriers directly impacts fish communities by limiting migratory movements. This work aims to understand how small barriers affect the movements of a potamodromous cyprinid species - the Iberian barbel (Luciobarbus bocagei (Steindachner, 1864)) - in a 5.6km upstream segment of a stream impacted only by the presence of physical barriers. Fish were marked with Visible Implant Elastomer tags (VIE), and barriers were seasonally characterized. A total of 683 fish were tagged, with 104 recaptures, during five sampling seasons (spring 2012 - early summer 2013). Eleven of the recaptured fish moved past a barrier, without any preference in terms of direction of movement. There were no differences in length, either between migrants and residents, or between upstream and downstream migrants. The results show that although barbel are able to negotiate small barriers, part of the population did not move between fragmented reaches - an indication that under such conditions, fish species populations may adjust their life-history strategy to augment residency as it was hypothesized from the results.
authors.affiliation: CEF - Forest Research Centre, Instituto Superior de Agronomia, Universidade de Lisboa, Lisboa, Portugal; CEris - Civil Engineering for Research and Innovation for Sustainability, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal. Electronic address: pjbranco@isa.ulisboa.pt.
authors.forename: Paulo
authors.initials: P
authors.lastname: Branco
authors.affiliation: CEF - Forest Research Centre, Instituto Superior de Agronomia, Universidade de Lisboa, Lisboa, Portugal.
authors.forename: Susana D
authors.initials: SD
authors.lastname: Amaral
authors.affiliation: CEF - Forest Research Centre, Instituto Superior de Agronomia, Universidade de Lisboa, Lisboa, Portugal.
authors.forename: Maria T
authors.initials: MT
authors.lastname: Ferreira
authors.affiliation: CEF - Forest Research Centre, Instituto Superior de Agronomia, Universidade de Lisboa, Lisboa, Portugal.
authors.forename: José M
authors.initials: JM
authors.lastname: Santos
mesh_terms: D025041:Animal Migration; D000818:Animals; D003530:Cyprinidae; D045483:Rivers; D012621:Seasons
keywords: Barrier negotiation; Fish migration; Partial migration; Potamodromous fish; VIE-tags