Jon C. Svendsen's research while affiliated with Technical University of Denmark and other places

... In addition, double-tagging enables to assess tag retention and effect (Brownscombe et al., 2019;Verhelst et al., 2022). Although limitedly studied , double-tagging comes with reasonable concern over an increased impact of the tagged fish' welfare and movement behaviour. ...

... Next, to obtain probabilistic inference on the effect of reef restoration, we computed BACI ratios via Markov Chain Monte Carlo (MCMC) sampling following the protocol described in and the equations from Wilms et al (2021). Briefly, "before" ratios are calculated for each MCMC iteration by extracting the fitted values (on the response scale) for impact (i.e. ...

... This proliferation of barriers to fish movement disrupts ecological connectivity, reducing the quantity of available suitable habitat necessary for lifehistory processes or dispersal (Fraik et al. 2021;Perkin et al. 2015;Nunn et al. 2008;Roni et al. 2002). This reduction in river connectivity alters fish assemblages, reduces population resilience to environmental disturbances and reduces genetic mixing (Jones et al. 2021;Rolls et al. 2013;Nunn and Cowx 2012). To understand the effect of cumulative impacts of barriers in river ecosystems, managers require an evidence-based, scientific approach. ...

... The increased availability of low-cost and high-quality image underwater cameras in recent years (Madsen et al., 2021) has enabled fishing gear technologists to qualitatively assess fish behavior with the aim of understanding the mechanics behind selection processes (Queirolo et al., 2010;Grimaldo et al., 2018;Larsen et al., 2018c). Even further, many studies have quantitatively analyzed the data gathered from underwater video to assess the selective device or fishing gear performance and species behavior (Bayse et al., 2014;Underwood et al., 2015;Bayse et al., 2016;Queirolo et al., 2019;Santos et al., 2020;Ahumada el al., 2021;Araya-Schmidt et al., 2021;Chladek et al., 2021a;Chladek et al., 2021b). The observed fish behaviors are usually tracked from the first detection to the final outcome of the selection process and categorized in stages. ...

... DCI P considers that all barriers are 'impassable' (Cote et al., 2009). Although this may seem overly restrictive for some fish species, all planned dams will reduce stream connectivity and by 'impassable' we really mean 'impactful', as we acknowledge that all barriers have selective effects on river-resident fish (Jones et al., 2020b;Jones et al., 2021a) as well as wider impacts on taxa other than fish (Jones et al., 2020a;Jones et al., 2021b). BFL and I Max are measured in km, are scale-dependent and increase with basin size for a given number of barriers. ...

... The increased availability of low-cost and high-quality image underwater cameras in recent years (Madsen et al., 2021) has enabled fishing gear technologists to qualitatively assess fish behavior with the aim of understanding the mechanics behind selection processes (Queirolo et al., 2010;Grimaldo et al., 2018;Larsen et al., 2018c). Even further, many studies have quantitatively analyzed the data gathered from underwater video to assess the selective device or fishing gear performance and species behavior (Bayse et al., 2014;Underwood et al., 2015;Bayse et al., 2016;Queirolo et al., 2019;Santos et al., 2020;Ahumada el al., 2021;Araya-Schmidt et al., 2021;Chladek et al., 2021a;Chladek et al., 2021b). The observed fish behaviors are usually tracked from the first detection to the final outcome of the selection process and categorized in stages. ...