Effects of surgically implanted tags and translocation on the movements of common bream Abramis brama (L.)

<p>Data collected from wildlife telemetry studies relies on tagging and attachment having minimal impactson behaviour. Though a widespread technique, relatively few studies evaluate the impacts of differingtagging methods on both welfare and behaviour. Here we use tracking data, collected for other aims, toinvestigate the impact of inter-peritoneal surgical implantation of acoustic transmitters on the healthand behaviour of common bream, Abramis brama (L.). In five separate capture events, the behaviour interms of distances moved and linear range of newly tagged fish (n = 61) were compared to previouslytagged fish (n = 55) present in the same river at the same time. In the first 5 days post-tagging, newlytagged fish moved significantly further than previously tagged fish. Despite this difference, the linearranges moved by the two groups of fish were equivalent. During 6–10 days post tagging there was nosignificant differences between the two groups. Thus, the tagging procedure had short term, but not longterm behavioural impacts. In addition, a number of tagged fish were recaptured between 51 and 461days post-surgery. Recaptured fish appeared to have clean, well-healed incisions and exhibited ‘normal’behaviour in that they were caught alongside a large number of conspecifics. Three recaptured taggedfish were translocated ?35 km downstream, to ascertain how translocation would affect their behaviour.The translocated fish had a greater linear range than control fish, with all three fish returning to the siteof capture within 6 to 24 days, suggesting that common bream can exhibit site fidelity.</p>