Fish catchability and comparison of four electrofishing crews in Mediterranean streams
dc.contributor.author
dc.date.accessioned
2016-05-06T11:40:24Z
dc.date.available
2016-05-06T11:40:24Z
dc.date.issued
2012
dc.identifier.issn
0165-7836
dc.identifier.uri
dc.description.abstract
The knowledge of capture efficiency and side effects of electrofishing is essential for research and monitoring of stream fish populations. Differences amongst electrofishing crews have hardly been investigated and are particularly important given the on-going implementation of the Water Framework Directive and wide-ranging exchange of data worldwide. We aimed to assess fish catchability in Mediterranean streams and to compare four electrofishing crews (with minor differences in gears used) and their short-term effects on fish populations. In eight different sites, we compared two adjacent stations, one sampled with conventional single-pass catch-effort data and the other closed with block nets and with four-pass removal estimates. We used a Williams' cross-over design to estimate the independent effects of repeated sampling in four consecutive days, site and crew and also to assess a potential carry-over effect. We modelled capture probability and estimated population size using program MARK and an information-theoretic framework. Our results show that electrofishing was generally efficient in these reaches, with 50-100% of the species and of 40-60% of the individuals captured in a single pass. The CPUE was significantly higher at sites blocked with nets than at open sites, but observed richness was not significantly different. Capture probability was generally not constant along removal passes and increased with fish size. Observed fish richness and species composition did not depend on electrofishing crew and fishing day and there was no significant carryover effect. There were, however, significant differences in single-pass CPUE estimates amongst electrofishing crews, after accounting for other sources of variation. There was also a significant carry-over effect, surprisingly with increasing fish captured after fishing by specific crews. Overall, our results suggest that although capture probability depends heavily on a number of factors (such as species, size, and sampling site) and needs careful consideration, the effect of electrofishing crew is negligible for assessment of species richness and composition but considerable for fish abundance
dc.description.sponsorship
This study was financially supported by the Catalan Water Agency (project Ibicat2) and the Spanish Ministry of Science (projects
CGL2009-12877-C02-01 and Consolider-Ingenio 2010 CSD2009-00065)
dc.format.mimetype
application/pdf
dc.language.iso
eng
dc.publisher
Elsevier
dc.relation
MICINN/PN 2010-2012/CGL2009-12877-C02-01
info:eu-repo/grantAgreement/MICINN//CSD2009-00065/ES/Evaluación y predicción de los efectos del cambio global en la cantidad y la calidad del agua en ríos ibéricos/
dc.relation.isformatof
Reproducció digital del document publicat a: http://dx.doi.org/10.1016/j.fishres.2011.11.022
dc.relation.ispartof
© Fisheries Research, 2012, vol. 123-124, p. 9-15
dc.relation.ispartofseries
Articles publicats (D-CCAA)
dc.rights
Tots els drets reservats
dc.subject
dc.title
Fish catchability and comparison of four electrofishing crews in Mediterranean streams
dc.type
info:eu-repo/semantics/article
dc.rights.accessRights
info:eu-repo/semantics/embargoedAccess
dc.embargo.terms
Cap
dc.date.embargoEndDate
info:eu-repo/date/embargoEnd/2026-01-01
dc.type.version
info:eu-repo/semantics/publishedVersion
dc.identifier.doi
dc.identifier.idgrec
017259
dc.contributor.funder
dc.relation.ProjectAcronym