Using simulated escape events to assess the annual numbers and destinies of escaped farmed Atlantic salmon of different life stages from farm sites in Norway

11493 7 77207 2 213328 document 77207 SkilbreiEtAl2014-IIASA version.pdf application/pdf 373c2b45cddecb5237188b6b7b697c26 MD5 1034424 2017-04-27 10:56:24 https://pure.iiasa.ac.at/id/eprint/11493/1/SkilbreiEtAl2014-IIASA%20version.pdf 11493 1 1 application/pdf text en public cc_by

SkilbreiEtAl2014-IIASA version.pdf

accepted 77208 2 213331 document 77208 lightbox.jpg image/png 8e4cc4f0b29bb6c4e08868aa3da5edce MD5 50967 2017-04-27 11:06:53 https://pure.iiasa.ac.at/id/eprint/11493/2/lightbox.jpg 11493 2 2 image/png other Thumbnails conversion from text to thumbnail_lightbox en public

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http://eprints.org/relation/isVersionOf https://pure.iiasa.ac.at/id/document/77207 http://eprints.org/relation/isVolatileVersionOf https://pure.iiasa.ac.at/id/document/77207 http://eprints.org/relation/isIndexCodesVersionOf https://pure.iiasa.ac.at/id/document/77207 archive 351 disk0/00/01/14/93 2016-01-15 08:53:29 2021-08-27 17:25:11 2016-01-15 08:53:29 article show Skilbrei O.T. Heino M. 7602 0000-0003-2928-3940 Svasand T. Using simulated escape events to assess the annual numbers and destinies of escaped farmed Atlantic salmon of different life stages from farm sites in Norway pub iis_ecl prog_eep environmental risks; escapements; farmed Atlantic salmon; fish farms; recapture To improve assessments of the environmental risks of aquaculture, a series of simulated escapes of farmed Atlantic salmon (Salmo salar L.) from seawater netpens were performed. Individually tagged post-smolts and adult Atlantic salmon were released from various locations at different times of the year. Post-smolts that escaped during their first summer were capable of rapid migration towards the open sea. A small fraction returned to spawn and were recaptured after 1.3 years at sea (0.4%, range 0.0.1.1%). A total of 13% of the post-smolts that escaped during autumn were reported in nearby fisheries during subsequent months, partly because they had grown large enough to be caught in the gillnets used, but more importantly because migratory behaviour diminished towards the end of the year. The mean recapture rate of adult salmon was high after releases in fjords (7.33%), lower after coastal releases (4.7%), and zero on the outer coast. Most of these recaptures were immature fish recaptured in sea relatively close to the release site during their first months post-release. Recaptures of adult escapees after 1.2 years in the wild were very rare (0.09%), probably because of their low survival. A Monte-Carlo method was developed to estimate the annual numbers of escapees from Norwegian fish farms based on reported catches of escaped farmed salmon in te sea and in rivers and the recapture probabilities reported here. The model provides a tool to estimate numbers of escapees independently from the reported numbers. Importantly, our analysis suggests that the total numbers of post-smolt and adult escapees have been two- to fourfold as high as the numbers reported to the authorities by fish farmers, depending on whether the incomplete sea fishery statistics are compensated for. 2015-02 published Oxford University Press 10.1093/icesjms/fsu133 XJ-15-069 ICES journal of Marine Science; 72(2):670-685 (Febraury 2015) (Published online 9 August 2014) [doi:10.1093/icesjms/fsu133] 122 public ICES journal of Marine Science 72 2 670-685 TRUE 1095-9289 FALSE info:eu-repo/semantics/article