This record provides an overview of the scope and research output of NESP Marine Biodiversity Hub Emerging Priorities project - "Spatial distribution of marine wildlife in the Bremer Bay region". For specific data outputs from this project, please see child records associated with this metadata.
The Bremer Canyon system is a recognised aggregation area for marine wildlife and predictable aggregations of the orca (Orcinus orca) underpin local ecotourism. Additionally, the value of the region has been recognised in the establishment of the Bremer Commonwealth Marine Reserve (CMR) (https://www.environment.gov.au/topics/marine/marine-reserves/south-west/bremer) and the identification of the Albany canyon group and adjacent shelf break as a Key Ecological Feature in the South-West Marine Bioregional Plan (https://www.environment.gov.au/sprat-public/action/kef/view/23;jsessionid=01AD87551D0DE1B0248C8722BE137004).
Little is known about the shelf and canyon region given its remote location and the relatively high cost of conducting offshore research. However, citizen-driven science has documented a stable aggregation of marine wildlife including orcas, sperm whales (Physeter microcephalus), and giant squid (Architeuthis sp.) occurring to the west of the established CMR. There is also speculation that this stable wildlife aggregation may be driven by seabed oil seeps with a hydrocarbon-based food chain although this is unsubstantiated.
The potential uniqueness of this wildlife aggregation within the region and what drives its presence remains unknown. There is a significant need to determine the regional importance of this aggregation and its relation to the existing protection afforded by the Bremer CMR.
The objective of this project is to improve the understanding of the importance of the Bremer CMR and surrounding region to marine wildlife. The project will determine the distribution of key wildlife of interest across the recognised pelagic aggregation and the Bremer CMR in order to inform Australian Government decision-making to protect the environment, conserve biodiversity and allow for sustainable use. The project will also improve understanding about the likely causes for wildlife aggregations and provide recommendations for future research options.
Planned Outputs
• A workshop of key experts, managers and external stakeholders to build on the literature review, identify additional data sources and recommend research priorities;
• A workshop report including a literature review to synthesise existing information, data and publications on the region in relation to wildlife aggregations, general ecology, oceanography and productivity;
• Marine wildlife survey – given the need to cover a large spatial area (i.e. the CMR and the known aggregation area in a single day), the preferred method is for an aerial survey with two observers. We propose that the team mobilises from Esperance given proximity to the CMR and ability to refuel etc. A team of two (2) scientific observers will be included plus an opportunity for an additional observer. The research will involve five (5) days of aerial surveying over no more than a seven (7) day period. The project will investigate the occurrence and distribution of orcas both inside and outside the known aggregation area (including the Bremer CMR).
• Analysis of existing acoustic data – Curtin University holds data from acoustic surveys and will interpret these data in the context of distinguishing the presence and distribution of orcas, other cetaceans and other biota.
• Analysis of existing orca distribution data within the aggregation – Curtin University has previously collected data on visual sightings of orcas at the aggregation. These data will be the spatial and temporal distribution of orcas at the aggregation site. This has the capacity to identify key patterns in orca behaviour within the known aggregation area.
• Collation of orca observations held by ecotourism operator Naturaliste Charter – this collation will provide the opportunity to determine how best to use these data and generate communication products given the collection of imagery.
• Pelagic fish survey – an existing planned survey to the Bremer CMR will be extended to include the aggregation area to allow the diversity, abundance and biomass of pelagic sharks and fishes in the CMR and the aggregation area to be compared. This will allow a comparison of the relative richness of the known aggregation area to the CMR with respect to pelagic shark and fish abundance.
• Hydrocarbon signals in squid - Preliminary investigation into whether hydrocarbon signals can be detected in squid as a first step in determining whether the wildlife aggregation may be supported by hydrocarbon seeps. Murdoch University hold squid samples from the aggregation area that form the basis of this analysis.
• Movement data to determine how adult orcas use the Bremer CMR and the aggregation area - tags will also be placed on at least three (3) adult orcas from the known aggregation site to clarify if those individual orcas are also transiting or using the Bremer CMR.
• Knowledge exchange and communication outputs – each component of the project will produce materials for use by Parks Australia. Likely considerations are 3D fly-thru, animations, infographics, brochure, videos, articles.
• Reporting outputs – a progress report focussing on completed field work and preliminary results will be produced followed by a final synthesis report.
