RT info:eu-repo/semantics/article
T1 Effects of whale-watching activities on southern right whales in Encounter Bay, South Australia
A1 Arranz Alonso, Patricia
A1 Sprogis, Kate R.
A1 Holman, Dirk
A1 Christiansen, Fredrik
A2 Biología Animal y Edafología y Geología
K1 Eubalaena australis
K1 Behavioural response
K1 Drone
K1 Environmental impact assessment
K1 Focal follows
K1 Vessel noise
AB Southern right whales (Eubalaena australis) are listed as Endangered under the Australian EPBC Act 1999. They migrate to shallow, coastal waters during the winter to mate, calve and nurse their young. During this time, theyare easily accessible to the boat-based whale-watching industry. The aim of the study was to determine if whalewatchingat 300 m distance affects the behaviour of southern right whales. To achieve this, behavioural focalfollows on mother-calf pairs were conducted using unmanned aerial vehicles (UAVs) in the presence and absenceof a commercial whale-watching vessel. There was no significant effect of phase (control, before, during, after) onthe whales’ respiration rate, swim speed, nursing rate and duration, maternal rate of active behaviours, tactilecontact or calf pectoral fin contact. There was a significant reduction in resting between control and after phases,for both mothers (from 62% to 30%) and calves (from 16% to 1%). At 300 m distance and slow speed, vesselnoise was measured to be slightly above ambient noise at the lower TOL0.25 kHz band, however, vessel noise wasmasked by ambient noise within the higher frequency TOL2–10 kHz bands. A factor which may have contributed toa decline in resting after whale-watch approaches, was an increase in vessel speed upon departure, whichconsequently increased vessel noise. Based on this, we recommend that vessels maintain a slow speed (e.g., ≤10knots) within 1 km distance from the whales whilst conducting whale-watch activities.
SN 0308-597X
YR 2023
FD 2023
LK http://riull.ull.es/xmlui/handle/915/40772
UL http://riull.ull.es/xmlui/handle/915/40772
LA Inglés
DS Repositorio institucional de la Universidad de La Laguna
RD 17-nov-2025