title: Rising from the ashes: Changes in salmonid fish assemblages after 30 months of the Puyehue-Cordon Caulle volcanic eruption.
abstract: Events such as volcanic eruptions may act as disturbance agents modifying the landscape spatial diversity and increasing environmental instability. On June 4, 2011 the Puyehue-Cordon Caulle volcanic complex located on Chile (2236 m.a.s.l., 40° 02' 24" S- 70° 14' 26" W) experience a rift zone eruption ejecting during the first day 950 million metric tons into the atmosphere. Due to the westerly winds predominance, ash fell differentially upon 24 million ha of Patagonia Argentinean, been thicker deposits accumulated towards the West. In order to analyze changes on stream fish assemblages we studied seven streams 8, 19 and 30 months after the eruption along the ash deposition gradient, and compare those data to pre eruption ones. Habitat features and structure of the benthic macroinvertebrate food base of fish was studied. After the eruption, substantial environmental changes were observed in association with the large amount of ash fallout. In western sites, habitat loss due to ash accumulation, changes in the riparian zone and morphology of the main channels were observed. Turbidity was the water quality variable which reflected the most changes throughout time, with NTU values decreasing sharply from West to East sites. In west sites, increased Chironomid densities were recorded 8 months after the initial eruption as well as low EPT index values. These relationships were reversed in the less affected streams farther away from the volcano. Fish assemblages were greatly influenced both by habitat and macroinvertebrate changes. The eruption brought about an initial sharp decline in fish densities and the almost total loss of young of the year in the most western streams affecting recruitment. This effect diminished rapidly with distance from the emission center. Thirty months after the eruption, environmental changes are still occurring as a consequence of basin wide ash remobilization and transport.
authors.affiliation: Instituto de Investigaciones en Biodiversidad y Medioambiente, CONICET - Universidad Nacional del Comahue, Quintral 1250, Bariloche, Río Negro 8400, Argentina. Electronic address: maylallement@gmail.com.
authors.forename: Mailén
authors.initials: M
authors.lastname: Lallement
authors.affiliation: Instituto de Investigaciones en Biodiversidad y Medioambiente, CONICET - Universidad Nacional del Comahue, Quintral 1250, Bariloche, Río Negro 8400, Argentina. Electronic address: patriciomacchi@yahoo.com.ar.
authors.forename: Patricio J
authors.initials: PJ
authors.lastname: Macchi
authors.affiliation: Instituto de Investigaciones en Biodiversidad y Medioambiente, CONICET - Universidad Nacional del Comahue, Quintral 1250, Bariloche, Río Negro 8400, Argentina. Electronic address: pablo.vigliano@gmail.com.
authors.forename: Pablo
authors.initials: P
authors.lastname: Vigliano
authors.affiliation: Instituto de Investigaciones en Biodiversidad y Medioambiente, CONICET - Universidad Nacional del Comahue, Quintral 1250, Bariloche, Río Negro 8400, Argentina. Electronic address: santiagomartinjuarez@gmail.com.
authors.forename: Santiago
authors.initials: S
authors.lastname: Juarez
authors.affiliation: Instituto de Investigaciones en Biodiversidad y Medioambiente, CONICET - Universidad Nacional del Comahue, Quintral 1250, Bariloche, Río Negro 8400, Argentina. Electronic address: magalirechencq@gmail.com.
authors.forename: Magalí
authors.initials: M
authors.lastname: Rechencq
authors.affiliation: University of Maryland Baltimore County, Baltimore, MD 21250, USA. Electronic address: mbaker@umbc.edu.
authors.forename: Matthew
authors.initials: M
authors.lastname: Baker
authors.affiliation: Eco Logical Research, Inc., PO Box 706, Providence, UT 84332, USA. Electronic address: nbouwes@gmail.com.
authors.forename: Nicolaas
authors.initials: N
authors.lastname: Bouwes
authors.affiliation: Department of Watershed Sciences and The Ecology Center, Utah State University, Logan, UT, USA. Electronic address: facrowl@gmail.com.
authors.forename: Todd
authors.initials: T
authors.lastname: Crowl
mesh_terms: D000818:Animals; D002677:Chile; D017753:Ecosystem; D004784:Environmental Monitoring; D045483:Rivers / Q000737:chemistry*; D012487:Salmonidae / Q000145:classification* / Q000254:growth & development; D018707:Volcanic Eruptions
keywords: Ashes; Disturbance; Fish assemblages; Macroinvertebrates; Volcanic eruption