Acoustic telemetry for marine animal and environmental monitoring: Technologies, challenges, and emerging trends.

Acoustic telemetry is a fundamental tool for tracking marine animals, providing long-term data that support fisheries management, conservation, and ecosystem-based monitoring. Advances in acoustic tags, receiver arrays, and sensor-integrated transmitters have expanded the ability to quantify animal movement, habitat use, and physiological responses across diverse marine environments. However, the long-term deployment of telemetry systems remains constrained by limited power supply, device size, detection performance in complex habitats, and environmental interference. This review provides an in-depth analysis of the fundamental principles and system architectures of acoustic telemetry, with emphasis on tag design, sensing capabilities, positioning approaches, and data workflows. It further highlights major marine monitoring applications, including pollution impact assessment, climate change response, marine protected area (MPA) design, and combating illegal, unreported, and unregulated (IUU) fishing. To address persistent energy and durability limitations, the review synthesizes emerging advances in sustainable power strategies, including flexible, self-healing, stretchable, and biodegradable energy-harvesting and storage materials, as well as ocean-wave energy-harvesting technologies for autonomous, long-term deployment. By linking recent progress in acoustic telemetry with sustainable energy solutions, this paper identifies current challenges and future directions for resilient, environmentally responsible, next-generation marine observation platforms.