Marine Ecoacoustics and Informatics Lab

Studying the dynamics of marine ecosystems through informatics

Welcome to the MEIL based in Biodiversity Research Center, Academia Sinica. Led by Dr. Tzu-Hao Lin, the MEIL investigates the applications of ecological informatics in biodiversity monitoring and conservation management.

Ocean sound is one of our primary subjects. We integrate passive acoustics and machine learning to track the spatial-temporal changes of biotic and abiotic sounds. By characterizing soundscapes, we seek to understand the mutual impacts among marine ecosystems, climate change, and anthropogenic activities.

We also interest in other non-acoustic techniques that can visualize the dynamics of marine ecosystems. Our goal is to generate open data and reusable models that can facilitate the retrieval of ecological information and increase the efficiency of decision making.

Topics

Mini-symposium on cetacean ecology

December 2, 2020 (Wednesday)

Biodiversity Research Center, Academia Sinica

Taiwan features a rich diversity of cetaceans. Studies on cetacean ecology are rapidly growing in recent years. This mini-symposium will review past studies on cetacean ecology in Taiwan and discuss future research directions.

Visualizing coral reef soundscapes using Soundscape Viewer and Plotly

Ever wonder how a coral reef sounds like? Ecoacoustics researchers generally use a long-term spectrogram to investigate the variation of long-duration recordings in spectral, temporal, and spatial domains. If you are interested in this technique, we have created a tutorial of using Soundscape Viewer and Plotly to visualize coral reef soundscapes.

Check our deep-sea soundscape project featured in the New York Times !

The Ocean Biodiversity Listening Project is now supported by the Ministry of Science and Technology, Taiwan!

Using Soundscapes to Assess the Interactions between Soniferous Animals and Anthropogenic Activities in Coral Reefs and Seagrass Beds

Conservation of marine biodiversity is crucial for maintaining sustainable marine ecosystem services. To efficiently investigate the potential interference of anthropogenic activities on marine biodiversity, a remote-sensing network that can characterize marine biodiversity's temporal-spatial variability is necessary. The recent development of underwater technology has allowed researchers to evaluate marine ecosystem change by using autonomous audio recorders to detect underwater sounds of marine soniferous animals, geophysical events, and anthropogenic activities. Until now, the analysis of marine soundscapes remains challenging because a comprehensive audio recognition database is not available. Moreover, the analysis reliability may be lowered when an audio clip records multiple sound sources simultaneously. This study will collaborate with scientists from Japan and the Philippines to initiate Ocean Biodiversity Listening Project and collect underwater sounds from coral reefs and seagrass beds via long-term recording stations and transect line surveys. New models of audio source separation and source localization will be developed by integrating domain knowledge from bioacoustics, signal processing, and machine learning. The techniques developed in this study will enable the automatic separation of biological, environmental, and anthropogenic sounds. The acoustic diversity observed in this study will enrich the audio library of coral reefs and seagrass beds, and improve the evaluation of how marine soniferous animals vary among habitats with different levels of anthropogenic activities. This study will also characterize the marine soundscapes during the COVID-19 pandemic in order to understand changes of marine biodiversity in response to the COVID-19 induced lockdown restrictions.

An online GIS of mass stranding events of Taiwan

This interactive map is created via CARTO. We hope such an interactive map can help stakeholders and citizens understand the history of mass stranding events happened in Taiwan and the species-specific stranding hot spots. We also published a short article (in Chinese) to comment on the recent event of a group of pygmy killer whales lost their way in Kaohsiung Harbor.

Visualizing soundscapes by using the Soundscape Viewer

In 2019, we published the Python version of Soundscape Viewer in Github. The Soundscape Viewer is an open toolbox of soundscape information retrieval that can assist in the visualization of long-duration recordings, source separation, and event identification. The toolbox features unsupervised learning models, which can greatly reduce the time needed in recognition of various sound sources. The Python version also allows users to access audio data from cloud-based platforms (e.g., Google Drive). We invite you to try the Soundscape Viewer in Google Colab, and start your ecoacoustics projects!

Recent Outcomes

Joseph Heard, Wei-chen Tung, Yu-de Pei, Tzu-Hao Lin, Chien-Hsiang Lin, Tomonari Akamatsu, Colin KC Wen (2020) Coastal development threatens area supporting greatest fish diversity at Taoyuan Algal Reef, NW Taiwan. Aquatic Conservation: Marine and Freshwater Ecosystems, early view.

Taoyuan Algal Reef is a biodiverse coralline algal reef in north‐west Taiwan, that is currently threatened by coastal development and industrial waste runoff. As the reef lies in an exposed area that is frequently disturbed by monsoons, it is difficult to survey using traditional methods. Knowledge of the reef is therefore limited, and has until recently, long been regarded as a barren environment.

We applied soundscapes to assess the quality of algal reef habitats. Our result revealed a positive relationship between the intensity of crustacean sounds and the abundance of tidal pool fishes. The observed soundscapes suggest that there are abundant prey resources for the fish community of algal reef. This study also demonstrated the effectiveness of using soundscapes in the monitoring of marine biodiversity at a challenging environment like algal reefs.

T. Aran Mooney, Lucia Di Iorio, Marc Lammers, Tzu-Hao Lin, Sophie Nedelec, Miles Parsons, Craig Radford, Ed Urban, Jenni Stanley (2020) Listening forward: Approaching marine biodiversity assessments using acoustic methods. Royal Society Open Science, 7: 201287.

Passive acoustics has been widely employed in the monitoring of marine soniferous animals. Here, we provide a summary of the brief history of using passive acoustics to assess marine biodiversity and community structure, a critical assessment of the challenges faced, and outline recommended practices and considerations for acoustic biodiversity measurements.

Important considerations for the acoustical biodiversity assessments should include: (i) replication and site-selection, (ii) recording over sufficient timescales, (iii) evaluation of detectability, (iv) evaluation of propagation-related aspects, (v) making concurrent measurements of complementary variables, (vi) collection of pilot data and making those data available, and (vii) seeking to reduce acoustic noise.

Tzu-Hao Lin, Chong Chen, Hiromi Kayama Watanabe, Shinsuke Kawagucci, Tetsuya Miwa, Hiroyuki Yamamoto, Shinji Tsuchida, Yoshihiro Fujiwara (2020) Characterizing habitat-specific soundscapes in deep-sea benthic ecosystems. eDSBS.

Deep-sea environments are highly dynamic through space and time, but continuous observation over extended periods remains challenging. The monitoring of underwater soundscapes has been proposed as a rapid and cost-effective way to assess the community structure and population dynamics of marine soniferous animals. This passive sensing technology can also produce information associated with the surrounding geophysical environment and anthropogenic activities.

From July 2019 to March 2020, we deployed autonomous sound recorders on baited cameras, the Edokko MARK I, and other seafloor observation platforms of JAMSTEC to collect underwater sounds from multiple deep-sea habitat types with a bathymetric range between 250 m to 5500 m deep.

The spectral characteristics of deep-sea soundscapes significantly varied among habitats. In coastal regions, soundscapes at Tohoku waters (250 – 1011 m) and Sagami Bay (1700 m) were dominated by shipping noise. At the 1385 m deep Suiyo Seamount vent field, soundscapes were characterized by low-frequency sounds (<100 Hz) from venting orifices. Even at 5500 m deep, we could still detect sounds produced from soniferous fish and cetaceans.

Habitat-specific soundscapes are likely important for the dispersal and settlement of deep-sea larvae and should be carefully monitored, especially in habitats attracting mining interests such as vents. To further utilize soundscapes as a tool of deep-sea conservation, we urge for an international collaboration that aims to acquire long-duration recordings from both healthy ecosystems and those disturbed by anthropogenic activities.

Tzu-Hao Lin, Yu Tsao (2019) Source separation in ecoacoustics: A roadmap toward versatile soundscape information retrieval. Remote Sensing in Ecology and Conservation, 6: 236-247.

Interested in using source separation to advance the analysis of acoustic data? In this article, we reviewed techniques of monoaural audio source separation with the fundamental theories and assumptions behind them.

Tzu-Hao Lin, Chong Chen, Hiromi Kayama Watanabe, Shinsuke Kawagucci, Hiroyuki Yamamoto, Tomonari Akamatsu (2019) Using soundscapes to assess deep-sea benthic ecosystems. Trends in Ecology & Evolution, 34: 1066-1069.

Have you ever listened to the deep ocean? The bathyal zone is never a silent world, and deep-sea animals may rely on soundscapes as the acoustic signpost for dispersal and settlement. However, mining, shipping, and various anthropogenic activities will alter the habitat-specific soundscapes. Such impacts may reduce the resilience of deep-sea ecosystems, and we urge for a global collaborative effort in using soundscapes as a new conservation tool.