Continental-scale animal tracking reveals functional movement classes across marine taxa

TLDR

Acoustic telemetry is a key tool for observing aquatic animals, yet large‑scale coverage remains a challenge. The study aims to evaluate the utility of a continental‑scale acoustic network for monitoring animal movement ecology and to identify the spatial scales over which it operates. Australia’s Integrated Marine Observing System’s Animal Tracking Facility uses a continental‑scale hydrophone array and coordinated data repository to connect localized projects and monitor multiple species across scales from hundreds of meters to thousands of kilometers. Cluster analyses of 2181 individuals from 92 species identified four functional movement classes based on individual movement metrics, revealing plasticity across populations and species, while network analyses showed multiple spatial scales of connectivity driven by receiver positioning, highlighting the network’s importance for uncovering intra‑specific movement differences and informing management.

Abstract

Abstract Acoustic telemetry is a principle tool for observing aquatic animals, but coverage over large spatial scales remains a challenge. To resolve this, Australia has implemented the Integrated Marine Observing System’s Animal Tracking Facility which comprises a continental-scale hydrophone array and coordinated data repository. This national acoustic network connects localized projects, enabling simultaneous monitoring of multiple species over scales ranging from 100 s of meters to 1000 s of kilometers. There is a need to evaluate the utility of this national network in monitoring animal movement ecology, and to identify the spatial scales that the network effectively operates over. Cluster analyses assessed movements and residency of 2181 individuals from 92 species, and identified four functional movement classes apparent only through aggregating data across the entire national network. These functional movement classes described movement metrics of individuals rather than species, and highlighted the plasticity of movement patterns across and within populations and species. Network analyses assessed the utility and redundancy of each component of the national network, revealing multiple spatial scales of connectivity influenced by the geographic positioning of acoustic receivers. We demonstrate the significance of this nationally coordinated network of receivers to better reveal intra-specific differences in movement profiles and discuss implications for effective management.