Oceanic telemetry detections using the Live hydrophone and the unmanned surface vehicle AutoNaut

Photo: 3D model of the AutoNaut USV (Dallolio et al., 2022)

Written by: Hilde Johannesen

Fish telemetry has been an essential contribution to the remote study of fish behaviour for the past decades. Combining the acoustic telemetry approach with unmanned surface and underwater vehicles, an early-stage energy-autonomous robotic fish telemetry platform was set up for a possible extended detection range for acoustic signals. The unmanned surface vehicle AutoNaut (as pictured), together with payload control, navigation and communication systems from the University of Science and Technology (NTNU) and an integrated Live hydrophone delivered from Thelma Biotel, make up the energy-autonomous robotic fish telemetry platform. Currently, fish movement studies suffer limitations due to stationary receiver range as well as the challenge of deploying receiver grids in open ocean environments. Deploying a Live receiver to an unmanned vehicle introduces a promising approach with the possibility to expand on the limitations faced in acoustic telemetry studies.

Introducing an energy-autonomous robotic fish telemetry platform

NTNU AMOS – Centre for Autonomous Marine Operations and Systems, The Faculty of Biosciences and Aquaculture – Nord University and INAQ AS, Trondheim presents an article where Thelma Biotel’s Live is integrated on an alternative surface glider platform to create an energy-autonomous robotic fish telemetry platform.

To test the theory, the platform was deployed in and on the outskirts of a Norwegian fjord during the seaward migration of Atlantic salmon post-smolts to observe if it was possible to detect tagged individuals past the stationary receiver grid.   

Primary functionality trial in outer regions of a fjord in western Norway

A trial of the concept was tested both theoretically and experimentally by range testing and assessment at sea. In the trials, the vehicle was found to have a detection ability such as regular stationary receivers when propelled by waves.

Atlantic salmon post-smolt detection in the open ocean, past the fjord’s stationary receiver grid

The main finding of this study was the ability of the energy-autonomous robotic fish telemetry platform to detect a migrating Atlantic post-smolt as it migrated out into the ocean. Further evolvement of the platform can possibly widen the range of standard, passive receiver grids and their experimental designs.

This article was published in Frontiers in Marine Science and can be accessed here.