Quantifying and reducing the cost of tagging : combining computational fluid dynamics and diving experiments to reduce impact from animal-borne tags

Animal-borne instruments are essential research tools for ecologists and physiologists. An increasing number of studies have shown impacts of carrying a tag on behaviour and energetics, which can have implications for animal welfare and data validity. Such impacts are a result of the additional mass and/or drag loads, with the latter requiring empirical measurements or computational fluid dynamics (CFD) to estimate. To quantify and effectively minimize tag impacts from drag, a novel combined empirical and CFD approach is required. Here, we demonstrate such an approach using captive phocid seals and the widely used Sea Mammal Research Unit (SMRU) Instrumentation Group GPS/GSM tag. We (i) show a significant change in the behaviour of grey seals when carrying a tag (gen 1; associated with 16.4% additional drag); (ii) redesigned the tag (gen 2) resulting in a lower additional drag of 8.6%; (iii) show significant differences in behaviour when carrying a gen 2 compared to gen 1 tag, demonstrating that the redesign successfully reduced impact; and (iv) observed changes in the swim speed of seals that were consistent with predictions from CFD estimates of drag. The gen 2 instrument is now commercially available. This non-trivial case study should pave the way for similar studies in other taxa and species.

Bibliographic Details

Main Authors:	McKnight, J.C., Pass, Chris, Thompson, Dave, Balfour, Steve, Brasseur, Sophie M.J.M., Embling, Clare, Hastie, Gordon, Milne, Ryan, Kyte, Adam, Moss, Simon E.W., Pemberton, Richard, Russell, Debbie J.F.
Format:	Article/Letter to editor biblioteca
Language:	English
Subjects:	3 Rs, CFD, biologging, diving animals, tag effects, telemetry,
Online Access:	https://research.wur.nl/en/publications/quantifying-and-reducing-the-cost-of-tagging-combining-computatio
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