Data from randomized control trials released hatchery salmon treated with anti-parasitic treatment

• Main Authors: Bjørn Torgeir Barlaup, Knut Wiik Vollset, Robert J Lennox, Helge Skolgund, Ørjan Karlsen, Eirik Straume Normann, Tore Wiers, Lisa Stöger
• Format: Dataset
• Language: English
• Published: 2022
• Subjects: Atlantic salmon; salmon louse; Randomized control trials; emamectin benzoate; Manger
• Online Access: https://zenodo.org/record/7081739; https://doi.org/10.5281/zenodo.7081739

Data used in the article "Parasite spillback from fish farms reduce return rate of wild salmon" Each release group has been used as a randomized control trials (RCT) of hatchery reared salmon smolts where half of the fish has been treated with an antiparasitic drug. Description of this method has been given in various other publications (Vollset et al. 2014, Vollset et al 2016, Skilbrei et al. 2013). The method involves rearing salmon eggs originating from the national Gene Bank to smolt size in hatchery facilities during one year, and then treating the salmon smolts with fish feed pellets coated with emamectin benzoate (SLICE®). These fish are then released into the river or transported in tanks or mobile net pens further out in the fjord before release. The fish are tagged with either coded-wire-tags (CWT; years 2000-2017) or Passive Integrated Transponders (PIT; 2015-2019) so that it is possible to identify them as they are recaptured or registered on an antenna upon their return as adults. In a few trials, another antiparasitic treatment (Substance EX) has been used, but in most cases the EB has been the only available treatment. Releases of hatchery reared salmon in freshwater have not been successful in this system, i.e. very few fish have returned from any group released in the river, lakes or estuary of Vosso. Since the release groups are also a part of a restoration effort of the Vosso salmon, some years fish have only been released in the fjord. There has been some variation in the release sites in the fjords, but for the purpose of this study we group the release groups in either group that has been released in the outer fjord (70-105 km from the river mouth) and the inner fjord (15-70 km from the river mouth), and freshwater (approx -10 to 15 km from the river mouth). The two most prevalent locations are at Manger (WGS84; 60.63918, 4.92149) and Arna (WGS84; 60.50812, 5.37777). Sea lice surveillance Sea lice surveillance on sea trout has been conducted at Herdla, the northern peninsula of the island ...