Birds & fishes: Monitoring strategies to identify and assess impacts of submarine and aerial power cables

The BirdSentinel system, a video device with semi-automated recognition of bird species, was tested in 2019 in the south of France at two electrical substations during the spring bird migration. The number of intrusions, their duration and their distribution over time in the vicinity of power lines were recorded. Eight groups of birds were analysed, including Larids, small, medium and large raptors, Ciconiidae, Ardeidae and Anatidae. The use of video equipment makes it possible to analyse the behaviour of birds close to power lines and to estimate the collision rate.

The current VADE RETRO project aims at characterising the flight behaviour of birds nearby electricity transmission networks (high or very high voltage power lines) and assess the effectiveness of wire marking devices deployed on cables to increase their visibility to birds and thus reduce the risk of collision. The project is based on high-frequency GPS tracking data collected on golden eagles (Aquila chrysaetos) during the refurbishment of three powerlines in

South-East France, which will enable the high-resolution quantification of any cable avoidance behaviour and its spatial scale, according to a Before-After Control-Impact protocol.

In the marine environment, we will present the FISHOWF project, which has developed a methodology for fine-scale monitoring by acoustic telemetry of elasmobranch fish known to be electrosensitive. Passive acoustic telemetry provides data with high temporal and spatial resolution on the behaviour and movements of species, as monitoring can be carried out continuously and simultaneously at several locations/habitats, over long periods and on several individuals. Passive acoustic telemetry makes it therefore possible to develop a more complete picture of individuals' habitat use and occupancy on a continuous 24 h basis.

Taken together, these projects will enable the power transmission industry to envisage innovative environmental monitoring methods on mobile species, improving the characterisation of impacts in both environments, assessing the effectiveness of mitigation measures implemented during the construction or refurbishment of high-voltage power lines, and fostering new positive contributions.