Hello all, My co-authors and I are pleased to announce the publication of our open-access paper - Quantifying and reducing the cost of tagging: combining computational fluid dynamics and diving experiments to reduce impact from animal-borne tags. J. Chris McKnight, Chris Pass, Dave Thompson, Steve Balfour, Sophie M. J. M. Brasseur, Clare Embling, Gordon Hastie, Ryan Milne, Adam Kyte, Simon E. W. Moss, Richard Pemberton and Debbie J. F. Russell. https://doi.org/10.1098/rspb.2024.1441 Abstract: 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. The paper can be obtained at the following link: https://royalsocietypublishing.org/doi/full/10.1098/rspb.2024.1441 Kind Regards, Chris