Dataset of Acoustic Recordings of Bottlenose Dolphins Collected During Boat-Based Encounters Using HydroMoth Devices, Event 006 (2024-12-01)

Data Records

The data in this sampling event resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 1 records.

3 extension data tables also exist. An extension record supplies extra information about a core record. The number of records in each extension data table is illustrated below.

This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.

Versions

The table below shows only published versions of the resource that are publicly accessible.

How to cite

Researchers should cite this work as follows:

Chaparro Elias, L., Rodero, C., EMBIMOS research group (ICM-CSIC) & Associació Cetàcea. (2025). Dataset of Acoustic Recordings of Bottlenose Dolphins Collected During Boat-Based Encounters Using HydroMoth Devices, Event 006 (2024-12-01) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.15658353

Rights

Researchers should respect the following rights statement:

The publisher and rights holder of this work is Institut de Ciències del Mar (CSIC). This work is licensed under a Creative Commons Attribution Non Commercial (CC-BY-NC 4.0) License.

GBIF Registration

This resource has been registered with GBIF, and assigned the following GBIF UUID: 203112b0-8279-48c1-8bad-7e119bf64171.  Institut de Ciències del Mar (CSIC) publishes this resource, and is itself registered in GBIF as a data publisher endorsed by GBIF Spain.

Keywords

HydroMoth; Cetacean sound recording; Passive acoustic monitoring; PAMGuard; Citizen science; Participatory science; Marine mammals; Underwater acoustics;; Samplingevent

Contacts

Geographic Coverage

Approximately 5.3 nautical miles off the coast of Vilanova i la Geltrú, Spain, in the northwestern Mediterranean Sea (41° 8'13.18"N 1°45'3.22"E)

Taxonomic Coverage

scientificName: Tursiops truncatus taxonRank: species kingdom: Animalia phylum: Chordata class: Mammalia order: Cetacea family: Delphinidae genus: Tursiops species: Tursiops truncatus

Temporal Coverage

Project Data

Although the ROCCA model is capable of extracting up to 50 distinct acoustic features (see Oswald & Oswald, 2013, ROCCA User’s Manual), and the additional PAMGuard modules employed can generate over 300 supplementary acoustic parameters, only a targeted subset of variables relevant to this analysis has been retained in the final dataset published here. These selected variables focus on key click-related metrics (e.g., number of clicks, amplitude, and click type) and whistle-related characteristics (e.g., number of whistles, duration, mean frequency, and classification score). The variables were chosen based on their relevance to the study objectives and their suitability for downstream analyses. In total, the final subset comprises 15 variables, alongside standard metadata describing the sampling event and species occurrence, formatted according to the Darwin Core standard using the ExtendedMeasurementsAndFacts extension. These key data are provided alongside the audio files in WAV format, which are published at https://doi.org/10.5281/zenodo.15658353. Consequently, the acoustic recordings and their associated metadata are publicly available on Zenodo, while the complete set of over 300 measured variables, as well as all files containing the PAMGuard configuration—stored in the SQLite Databases and Binary Storage folders—are available upon request.

The personnel involved in the project:

Sampling Methods

The HydroMoth device was configured to capture high-frequency sounds at a sampling rate of 250 kHz, with medium gain. A band-pass filter ranging from 0.5 kHz to 125 kHz was applied. No amplitude threshold settings were enabled during the recording session. Upon sighting cetaceans and approaching them, the vessel’s engine was turned off to minimise acoustic disturbance, and the recorder was deployed at a depth of approximately 5 to 7 metres. The device remained submerged until the encounter was considered concluded—typically after several minutes without visual or acoustic detections, or when the animals were observed to be moving away or not returning. The recorder was then retrieved. Due to the high data volume generated by the recording settings (approximately 143 MB per 5 minutes at a 250 kHz sampling rate), the audio files were segmented into 1-minute clips prior to processing. This was done to reduce individual file sizes and enable their upload to open repositories—particularly those linked to citizen science initiatives—which often impose a maximum file size limit of 20 MB.

Method step description:

1. All acoustic data recorded during the deployments were analysed both aurally and visually using the open-source software PAMGuard (version 2.02.16; DOI: 10.5281/zenodo.15056259) by biologists from the EMBIMOS research group at the Institut de Ciències del Mar (ICM-CSIC). The Whistle and Moan Detector and Click Detector modules were used to detect tonal and pulsed vocalisations, respectively. The ROCCA module (Real-time Odontocete Call Classification Algorithm) was employed to measure whistle contours, which were manually extracted using the contour-extraction graphical interface (see Oswald & Oswald, 2013, ROCCA User’s Manual). Spectrograms were visualised with the following settings: FFT length = 2048, hop size = 1024, and a Hann window with 50% overlap, resulting in a temporal resolution of approximately 8.19 ms. Additional modules and visualisation tools were configured to assist in the inspection of low-frequency acoustic events. For a complete description of the analysis workflow and parameters, refer to the PAMGuard Configuration Overview included with the dataset, which enables interpretation and replication of the study.

Bibliographic Citations

1. Gillespie, D., Caillat, M., Gordon, J., & McHugh, R. (2020). PAMGuard: Open Source Software for Real-time Acoustic Detection and Localisation of Cetaceans (Version 2.02.16) [Computer software]. Zenodo. https://doi.org/10.5281/zenodo.15056259 https://doi.org/10.5281/zenodo.15056259
2. Oswald, J. N., & Oswald, M. (2013). ROCCA (Real-time Odontocete Call Classification Algorithm) User's Manual. Submitted to HDR Environmental, Operations and Construction, Inc. Norfolk, Virginia under Contract No. CON005-4394-009, Subproject 164744, Task Order 03, Agreement # 105067. Prepared by Bio-Waves, Inc., Encinitas, California.
3. Open Acoustic Devices. (2024, June 6). AudioMoth Operation Manual. [Online]. Available: https://www.openacousticdevices.info/s/AudioMoth-Operation-Manual.pdf

Additional Metadata