Aquaculture Europe 2021

October 4 - 7, 2021

Funchal, Madeira

Add To Calendar 05/10/2021 16:50:0005/10/2021 17:10:00Europe/LisbonAquaculture Europe 2021HOW DOES TAG IMPLANTATION AFFECT THE BEHAVIOUR OF EUROPEAN SEABASS Dicentrarchus labrax?Lisboa-HotelThe European Aquaculture Societyalistair@aquaeas.eufalseanrl65yqlzh3g1q0dme13067DD/MM/YYYY


Dimitra G. Georgopoulou1  *, Orestis Stavrakidis-Zachou1,2, Nikos Mitrizakis1, Nikos Papandroulakis1

 1. Institute of Aquaculture, Hellenic Centre for Marine Research, AquaLabs , 71500, Gournes , Heraklion, Greece

2. Department of Biology, University of Crete, 71003 Heraklion, Greece




The usefulness of ultrasonic telemetry on behavioral studies has been proven by a large number of field and laboratory studies (i.e. Abecasis et al, 2018; Schwinghamer, 2019). However, telemetry tags may have an effect on the physiological, behavioral and the performance attributes of the fish (Frank et al, 2009, McKenna et al, 2021) and could be permanent or temporal. These potential negative effects are still unknown for a number of species and tagging methods. Recent studies exist and focus mainly on the physiological and anatomical consequences of tag-implantation (Tsitrin, 2020; Justin et al, 2021). It is, thus, crucial to determine the behavioral attributes that are affected by the tag implantation, and the time needed for recovery. Here, we investigated the effect of body-implanted tags on the swimming behavior of adult European seabass (Dicentrarchus labrax). Three main behavioral aspects were studied, including the synchronization/polarized motion, the group cohesion and the group exploratory behavior.

Materials and methods

45 individuals were captured and transferred from sea cages to a rectangular tank (3.0x3.0x1.2m) 30 days prior to the experiment to allow for adaptation. Polyacetal (POM) cylinders (similar in size and shape with telemetry tags) were implanted into the peritoneal cavity of 20 fish following an experimental protocol that was approved by the ethical committee (Ref: 32257 09-02-2021). The remained fish were used as the control group. After the surgery, fish returned to the tanks and were being recorded from above using fixed IP cameras (HIKVISION DS-2CD1623G0-IZS) for a total period of 15 days. During this period feeding was realized once per day at 12:00. The treated fish returned to normal appetite levels four days after the surgery.

From the video recordings, four main variables were extracted using custom-made computer vision routines based on Python/OpenCV. Group directionality and speed were extracted using optical flow analysis. Group cohesion was determined as the normalized tank area covered by the group at each time frame. Last, the exploratory tendency showed the spatial preference of the group and was expressed as the frequency each tank site was covered by the fish.


Preliminary results indicate that E. seabass exploratory behavior is temporally affected by the tag implantation but achieves recovery 10 days after surgery (figure 1A). In contrast, the group cohesion of the treated group remains high during the experiment as the group never covers more than the 40% of the tank area (figure 1B). Although the treated group becomes less cohesive as time progresses, the significant difference between the two groups remains, even 15 days after surgery. Further investigation is required to determine the time needed for recovery of this behavioural atrribute. 


Abecasis, D., Steckenreuter, A., Reubens, J. et al (2018) A review of acoustic telemetry in Europe and the need for a regional aquatic telemetry network. Anim Biotelemetry 6, 12.

Frank H.J., Mather M.E., Smith J.M. (2009) What is “fallback”?: metrics needed to assess telemetry tag effects on anadromous fish behavior. Hydrobiologia 635, 237–249.

James E. McKenna, Suresh A. Sethi, Grant M. Scholten, Jeremy Kraus, Marc Chalupnicki (2021) Acoustic tag retention and tagging mortality of juvenile cisco Coregonus artedi. Journal of Great Lakes Research,

Justin A.G. Hubbard, Brendan E. Hickie, Jeff Bowman, Lee E. Hrenchuk, Paul J. Blanchfield, and Michael D. Rennie (2021) No long-term effect of intracoelomic acoustic transmitter implantation on survival, growth, and body condition of a long-lived stenotherm in the wild. Canadian Journal of Fisheries and Aquatic Sciences. 78(2): 173-183.

Tsitrin E, McLean MF, Gibson AJF, Hardie DC, Stokesbury MJW (2020) Feasibility of using surgical implantation methods for acoustically tagging alewife (Alosa pseudoharengus) with V5 acoustic transmitters. PLOS ONE 15(11): e0241118.

Schwinghamer, C.W., Tripp, S. and Phelps, Q.E. (2019) Using Ultrasonic Telemetry to Evaluate Paddlefish Spawning Behavior in Harry S. Truman Reservoir, Missouri. North Am J Fish Manage, 39: 231-239.