Power Efficiency and Data Management with the icListen Hydrophone

To learn about the Barrow Strait project in the Arctic, we spoke with Jinshan Xu, an acoustics expert with Fisheries and Oceans Canada (DFO) who brings over 10 years of experience working with the icListen hydrophone.

Challenge

What does it take to deploy a hydrophone in the Arctic?

Ongoing in situ monitoring in Barrow Strait, located in the Northwest Passage, by Fisheries and Oceans Canada scientists at the Bedford Institute of Oceanography has been crucial in establishing a baseline of the ocean’s environment. This baseline is essential for assessing Arctic ocean sea-ice freeze-up and break-up on ecosystem dynamics, and predicting sea-ice processes based on water property measurements. However, the changing climate in Canada’s Arctic presents both challenges and opportunities. As the region warms faster than the global average, there is an urgent need to monitor these environmental changes and mitigate their impacts. Additionally, with the Arctic becoming more accessible due to ice melt, accurate, real-time data is essential to support increased maritime activity and responsible development.

In response to these needs, an ocean observatory was installed at the eastern end of the Northwest Passage in 2009, designed to provide hourly updates on ocean and ice conditions for mariners and climate modelers. Despite this advancement, the extreme Arctic environment presented significant challenges, particularly in selecting a hydrophone that could operate efficiently year-round. The primary challenge was to find a hydrophone that could minimize power consumption while ensuring the collection of only the most relevant data, avoiding system overload and maintaining continuous, reliable monitoring in such a harsh and remote location.

Solution

To meet the challenges of Arctic monitoring, the icListen hydrophone was selected for its high performance, dynamic range, and duty cycling capabilities—features that are crucial for operations in such a remote and harsh environment. The hydrophone’s ability to conserve power was particularly important given the extreme conditions and the need for long-term deployments.

A key advantage of the icListen is its on-board spectral processing, which reduces the volume of data the observatory system needs to handle. This capability was essential given the limitations of the submarine cable and Iridium satellite system for data transmission. The hydrophone was configured to sample for 60 seconds every two hours, which provided a balance between capturing necessary data and conserving power. The acoustic data, sampled at 2 kHz, is processed into a spectrum (from 0 to 800 Hz) every second and written to a compact 60 KB plain text file. This file is then transmitted up the cable with other data, ensuring efficient data management without overwhelming the system.

The hydrophone’s low power consumption enabled continuous operation throughout the year, even during the long Arctic winters, while its dynamic range captured high-quality acoustic data. The duty cycling feature was particularly beneficial, allowing the system to collect data only during specific periods, preventing data overload, and optimizing storage and transmission capacities.

Result

The integration of the icListen hydrophone into the Barrow Strait underwater observatory significantly enhanced the capabilities of Fisheries and Oceans Canada scientists in monitoring the Arctic environment. The hydrophone’s efficiency and reliability ensured the continuous collection of vital acoustic data, contributing to a deeper understanding of the rapidly changing Arctic environment.

This data has been instrumental in supporting predictions of sea-ice freeze-up and break-up, assessing ecosystem dynamics, and informing maritime and climate models. Furthermore, the ability to provide timely, relevant data has supported increased activity in the Arctic, enabling responsible development and safer navigation through the Northwest Passage. The icListen hydrophone has become a cornerstone of the Barrow Strait real-time observatory, playing a key role in both scientific research and practical applications in one of the most challenging environments on the planet.

Learn more about this project DFO’s Real Time Arctic Ocean Observatory