Southern right whales (Eubalaena australis) return to a former wintering calving ground: Fowlers Bay, South Australia
Marine Mammal Science
Centre for Marine Ecosystems Research
Research funding and Ph.D. scholarship stipend was provided by Murphy Australia Oil Pty. Ltd. and Santos Ltd. for 2014–2016 under project number RES-58756. Scholarships for Ph.D. student Claire Charlton were granted through Commonwealth Australian Postgraduate Award (APA) and Curtin University Postgraduate Scholarship (CUPS). The Australian Marine Mammal Centre (AMMC) provided funding for desk-based study to assess southern right whale population dynamics in Fowlers Bay (2012/2013) under grant number 12/21.
Southern right whales (SRW), Eubalaena australis, have reoccupied historically important winter habitat ranges (calving grounds) in recent years along the southern Australian coast. Here we present findings of increased abundance of SRW at Fowlers Bay, South Australia, a previous shore‐based whaling station. This study investigates: SRW inter‐ and intraseasonal trends in relative abundance; changes to the relative proportion of the southwestern subpopulation represented by SRW at Fowlers Bay; distribution; and occupancy. Sighting and photo identification data were collected during annual aerial (1993–2016) and vessel surveys (2014–2016). The total number of female and calf pairs was 3 during 1993–2003 and 63 during 2004–2014. Despite high variability in annual relative abundance, the rate of mean increase from 1993 to 2016 (29.0%/yr, 95% CI = 0, 54.2) exceeded the maximum biological rate for the species (6%–7%/yr). Peak relative abundance was recorded in July and August. SRW at Fowlers Bay represent an increasing proportion of the southwestern subpopulation (range = 0.9%–7.4%). Mean occupancy was 23 d (range = 1–75) for female and calf pairs and 2 d (range = 1–15) for unaccompanied adults. Reduced sightings in 2015 and 2016 demonstrate plasticity in SRW abundance at Fowlers Bay. Research into the movement and connectivity of SRW is needed to understand drivers of habitat dispersal in Australia.