Enhancing monitoring approaches to evaluate the abundance, life history and critical habitats of the endangered Australian sea lion

A better understanding of Australian sea lion abundance, life history and critical habitats is needed to evaluate these threats, and guide and evaluate recovery actions. Acquiring this knowledge is challenging due to the species’ unique life-history and breeding biology, longevity, seafloor foraging behaviour and remote breeding habitat.

This project will support the management and recovery of Australian sea lions by:

• improving methods for acquiring abundance data from under-surveyed regions impacted by fisheries bycatch and other pressures;
• using drones to enhance monitoring at breeding and haul-out sites;
• developing efficient techniques to process and analyse demographic data; and
• continuing to deploy underwater cameras on sea lions to identify and understand critical habitats and risks.

The project has been developed and co-designed with three Indigenous partners who will be responsible for delivering different components. They are Yalata Anangu Aboriginal Corporation, Far West Coast Aboriginal Corporation and Esperance Tjaltjraak Native Title Aboriginal Corporation (ETNTAC).

Approach

The project will cover four priority areas.

Survey of the Recherche Archipelago (WA)

The Recherche Archipelago represents ~35% of breeding colonies in WA, yet there is a lack of current data on abundance, and the timing of breeding at known breeding sites. This has made it difficult to evaluate trends for this sector of the population and the population as a whole. Contemporary abundance data is integral to evaluating and managing the impact of demersal gillnet fishing and other major threats. Helicopter surveys will assess the status of breeding sites, identify new breeding sites, and determine the breeding chronology at each site. At least one static camera with the ability to continuously record and transmit data remotely will be installed at a key site to identify breeding status and plan surveys that inform the timing of pup counts.

Drone surveys of key ASL breeding and haul-out sites (WA and SA)

Drones will provide baseline abundance data at suitable haul-out and breeding sites. This is particularly important in WA to identify sites where drones can be applied for ongoing monitoring of pup abundance, given the distances and difficult access at some sites. Drone surveys will be validated by on-ground counts. Different sensors will be trialled depending on site selection, habitat (vegetation, island topography) and animal abundance. These include photogrammetry, forward scanning infra-red (FLIR), thermal imaging and 3D-ranging (LiDAR). Methodologies will be tested to ensure adequate image resolution to differentiate between age classes and species, as fur seals are common at some sea lion breeding sites. ETNTAC rangers will be flying the DJI Matrice (drone) which ETNTAC is providing in-kind to this project.

Streamline Seal Bay demographic analysis (SA)

The long-term microchipping program at Seal Bay provides the only source of demographic data for Australian sea lions. The program provides basic knowledge about the species’ population demography (survival, age of first breeding, breeding success, longevity) essential to informing conservation actions. While these data have been collected for 20 years, survival and reproductive success analyses are complex and time consuming to undertake, and consequently, have been undertaken infrequently. We propose to streamline data extraction, checking, filtering, formatting, and analytical steps to facilitate regular reporting and analysis, to update population models needed to evaluate risk, cumulative impacts, and recovery actions. 

Deploy sea lion cameras to determine key habitats

This component will build on Project 2.6 which showcased the diversity of Australian sea lion habitat use. Underwater cameras will be further deployed at Seal Bay and other island sites off the western Eyre Peninsula, in Warungu Country, to broaden inter-colony comparisons and further develop First Nations engagement opportunities. Deployments at Seal Bay will explore the level of within-colony, inter-individual variability in habitat use and foraging strategies. Deployments off the western Eyre Peninsula will explore variability of habitat use and foraging behaviour among colonies.

Expected outcomes

This project will contribute essential data and insights for conservation decision-making and on-ground actions including:

• priorities identified by the Department of Climate Change, Energy, the Environment and Water Recovery Plan for the Australian Sea Lion;
• long-term monitoring and management of the Australian sea lion by state government departments;
• healthy Country management, and awareness of cultural connections with sea lions and sea Country; and
• Indigenous participants will be provided with opportunities to take leadership roles when monitoring sea lions using new technologies.

Project location