This record provides an overview of the NESP Marine and Coastal Hub bridging study - "Aerial survey of the Southern Right Whale ‘western’ sub-population off southern Australia". For specific data outputs from this project, please see child records associated with this metadata. -------------------- Aerial surveys of Southern Right Whales have been conducted across the southern Australian coast from Perth, WA to Ceduna, SA since 1993, as part of a long-term program to monitor their recovery. The surveys data provide a long-term population trend for this ‘western’ population, and provide an understanding of connectivity with the ‘eastern’ population as part of a national population assessment. The NESP Marine Biodiversity Hub funded the aerial surveys in 2015–2020 and the Marine and Coastal Hub funded the survey in 2021. (See Project 1.26: https://catalogue.aodn.org.au/geonetwork/srv/eng/catalog.search#/metadata/b85b2c7d-4631-477a-9217-2cae65f9cf0a) The 2022 survey ensures an uninterrupted time series in the long-term population trend data for this Endangered species. This is particularly important given the non-annual breeding cycle (typically every three years), such that annual surveys are essential to maintain an acceptable level of precision in estimating population trends and key life history parameters (calving intervals) to track the recovery of the species. Continued monitoring of the population is needed to evaluate whether there is a longer term and continuous change (in population size and calving intervals) in the population as indicated by recent sightings and population trend data. Outputs • Estimate of relative abundance and population trend compared to long-term aerial survey sightings [dataset] • Individual whale photo-identification data - 2021-22 season [imagery - published to ARWPIC] • Final technical report detailing overall numbers of southern right whales observed within the survey region, their gender (and life stage where possible) and spatial distribution of individuals [written]

This record provides an overview of the NESP Marine and Coastal Hub bridging study - "A photo-identification study of southern right whales to update aggregation area classification in the southwest of Australia". For specific data outputs from this project, please see child records associated with this metadata. -------------------- The southern right whale (Eubalaena australis) is listed as Endangered under the Environmental Protection and Biodiversity Conservation Act 1999 (EPBC Act) and is subject to conservation listings in five Australian states due to severe population declines caused by historical whaling. The Southern Right Whale Conservation Management Plan 2011–2021 outlines the current status of, and threats to, the southern right whale in Australian waters and prioritises recovery actions during this period. The long-term vision for the recovery of this species in Australian waters is to increase the population size to a level that the conservation status improves, and the species no longer qualifies for listing as threatened under any of the EPBC Act listing criteria. The plan must be periodically updated to reflect new knowledge and prioritise the research needed to monitor population recovery and predict the impacts of threats such as climate change. Aerial surveys of southern right whales have been conducted across the southern Australian coast from Perth (W.A.) to Ceduna (S.A.) since 1993, as part of a long-term program to monitor the recovery, and inform the Conservation Management Plan (2011-2021), for this Endangered species. In Australia’s south-east, there has been little sign of recovery in southern right whale numbers following intense commercial whaling. A working hypothesis assumes separation between the ‘western’ and ‘eastern’ populations, largely due to loss of ‘cultural memory’ of whales migrating to the eastern range breeding areas. Given the relative paucity of animals that visit the southern Australian coast in areas other than south-west Australia, the western population is considered to represent the majority of the ‘Australian’ southern right whale population. The count data from these aerial surveys provide data on population trend and estimates of population size for the ‘western’ population, and hence the majority of the Australian southern right whales. Associated photo-identification data provide life history information (such as calving intervals) and connectivity between the ‘western’ and ‘eastern’ populations and contribute to the national southern right whale photo-id database: the Australasian Right Whale Photo-Identification Catalogue (ARWPIC). The 2020 aerial survey program recorded substantially lower numbers of whales than in the previous 13 years, and the lowest number of non-calving whales since the program started. This project conducted new aerial surveying in August 2021 to provide a relative estimate of annual population size for determining longer term population trends and contribute to determining if 2020 was an anomalous year or an indicator of some longer-term change to recent recovery rates and the female breeding cycle. Outputs • Aerial whale survey data (counts by size class, number, and location) - 2021-22 season [dataset] • Individual whale photo-identification data - 2021-22 season [imagery - published to ARWPIC] • Final Project Report including a short summary of recommendations for policy makers of key findings [written]

Aerial surveys of southern right whales (Eubalaena australis) were undertaken off the southern Australian coast to monitor the recovery of this endangered species following extreme 19th and 20th Century commercial whaling. The aerial survey was undertaken in the coastal waters from Perth (Western Australia) to Ceduna (South Australia) between the 12th and 19th August 2022, to maintain the annual series of surveys and inform the long-term population trend. The survey resulted in a total 526 whales sighted, consisting of 247 cow-calf pairs, 31 unaccompanied adults and 1 yearling. The ‘western’ population of southern right whales in Australian waters is increasing in size (~5.3% per year based on female/calf pairs and a population estimate of 2675 whales) based on the long-term population trend data from the annual aerial surveys. This represents the majority of the Australian population given the very low numbers in the ‘eastern’ population. The 2022 surveys recorded the lowest number of unaccompanied animals (i.e. males and females without a calf) ever throughout the time-series of the annual aerial surveys since 1993 when survey coverage between Cape Leeuwin and Ceduna first began. Across this time series, there is a particularly notable decline in sightings of unaccompanied animals over the past five years. It is currently unclear what factors account for the decline in these sightings or may influence the variation in numbers of unaccompanied animals on the southern Australian coast. Lower than expected counts in the long-term data may provide evidence of a slowing population growth rate, which can only be assessed by continued annual population surveys to assess population trend data.

Aerial surveys of southern right whales (Eubalaena australis) were undertaken off the southern Australian coast to monitor the recovery of this endangered species following extreme 19th and 20th Century commercial whaling. The aerial survey was undertaken in the coastal waters from Perth (Western Australia) to Ceduna (South Australia) between the 12th and 17th August 2021, to maintain the annual series of surveys and inform the long-term population trend. The maximum whale counts for each leg of the survey flights between Cape Leeuwin and Ceduna, and consisted of a total 643 southern right whales sighted across the survey area (270 cow-calf pairs and 103 unaccompanied whales). The subsequent population estimate for the Australian ‘south-western’ population is 2,549 whales, which represents the majority of the Australian population given the very low numbers in the ‘south-eastern’ subpopulation. The population long-term trend data is indicating recent years (from 2007) are showing greater inter-annual variation in whale counts. To evaluate the recovery of the southern right whale population, it will be critical to collect long-term data on the annual variability in whale numbers related to the non-annual female breeding cycle and identify possible impacts on this by short-term climate dynamics, longer-term climate change and/or anthropogenic threats.

This record provides an overview of the NESP Marine and Coastal Hub Research Plan 2023 project "Informing southern right whale management through continued monitoring, determination of aggregation areas and development of approaches to increase data flow efficiencies and utility". For specific data outputs from this project, please see child records associated with this metadata. -------------------- This project will deliver priority information on southern right whales to address key knowledge gaps through: (i) updating long-term population abundance trends via aerial surveys of the western population and testing of platforms for improving photo-identification data flow efficiencies; (ii) the collection and utilisation of photos of the western population to identify biologically important reproductive areas and inform the estimation of population parameters;(iii) development of integrative methods for combining opportunistic and more formally collected observations, to expand the utility of datasets and (iv) collection of movement and genetic data to assess the connectivity and population identity of whales at the boundary of the eastern and western subpopulations. It will also conduct a consultative process for prioritising future work for informing future NESP work. Outputs • Updated southern right whale population assessments [dataset] • Individual whale photo-identifications in aggregation areas [image catalogue] • Updated SPRAT and BIA distributions [dataset] • Whale movement tracking [dataset] • Genetic data (for estimates of population connectivity) [dataset] • Final project report [written]