PRIN-SEAmPhonia

Programme: PRIN: PROGETTI DI RICERCA DI RILEVANTE INTERESSE NAZIONALE – Bando 2022

Project title: SEAmPhonia – An innovative enlightening approach to enable the modelling of marine ecosystems by the acoustic 3D field – 2022AWXT3K

Acronym: SEAmPhonia

Duration: dal 28/09/2023 al 28/02/2026

Project budget: € 273.540,00

ISMAR budget: € 161.357,00

Web site: https://www.ismar.cnr.it/seamphonia/

Contact person in ISMAR: angela.pomaro@cnr.it (Principal Investigator)

Partnership:

Consiglio Nazionale delle Ricerche (Italy)
Sapienza Università di Roma (Italy)
Università degli Studi di Padova (Italy)

Summary:

The marine environment is shaped by complex interactions between physical, chemical and biological variables, in addition to the influence of human activities. While advanced physical models and data assimilation techniques are available, comprehensive ecosystem models remain limited by the difficulty of integrating heterogeneous variables and multiple interconnected processes.

SEAmPhonia proposes a new observational approach, based on the analysis of the 3D underwater acoustic field, inspired by breakthrough methodologies in helioseismology. By deploying a matrix of sensors at sea and widening the analysis from classical frequency spectra to cross‑spectral methods (phase, coherence, wavelets), the project aims to identify the contributions of sea‑state dynamics, biological activity and anthropogenic noise.

This methodology is tested in a well‑known basin using a rare observing configuration not commonly available elsewhere. It allows linking local acoustic variability to large‑scale environmental processes.Questa metodologia viene testata in un bacino ben caratterizzato utilizzando una configurazione osservativa rara e difficilmente disponibile altrove. Ciò consente di collegare la variabilità acustica locale a processi ambientali su scala più ampia.

Project goals include:

Transferring knowledge from solar physics to marine acoustics to identify processes coupling physical, biological and anthropogenic components.
SviluppaTailoring fibre‑optic technology for marine applications.
Equipping and testing a long‑term observing platform in the Adriatic Sea.
Acquiring and comparing data across different geometries and ecosystem regimes.
Opening a new research line based on regime‑shift analysis in the 3D acoustic field.
Designing an efficient and cost‑effective marine observing strategy based on acoustics.

Why SEAmPhonia

L’oceano è un ambiente dinamico in cui numerose variabili interagiscono su molteplici scale. Nonostante i progressi della modellistica fisica, le previsioni su scala ecosistemica risultano ancora incomplete a causa della difficoltà di assimilare dati molto diversi tra loro e di rappresentare processi accoppiati.

SEAmPhonia addresses this challenge by using the 3D underwater acoustic field as a holistic environmental descriptor, leveraging the continuous, information‑rich nature of underwater sound.
This approach is inspired by helioseismology, which infers solar interior dynamics from surface oscillations. By analogy, underwater acoustics provides a window into otherwise hidden marine processes.

What We Do

Deploy a matrix of hydrophones at the Acqua Alta Oceanographic Platform (Northern Adriatic).
Extend acoustic analysis from traditional power spectra to cross‑spectral tools (phase, coherence, wavelets).
Develop and tailor fibre‑optic sensing technology for 3D marine acoustics.
Test long‑term observing strategies in a well‑characterised basin.

Workstreams & Outcomes

1. Science

Within the scientific work package, SEAmPhonia carried out a structured experimental programme to assess how the underwater acoustic field can reveal key marine processes. Six dedicated at‑sea experiments were conducted at the Acqua Alta Oceanographic Tower, supported by high‑resolution multi‑hydrophone measurements collected at sampling frequencies up to 128 kHz. These datasets underwent extensive processing to extract robust acoustic indicators.

The analysis led to two main results. A system‑state indicator was identified from the power spectrum of high‑frequency acoustic signals, hypothesising a connection with biological activity. In parallel, a sea‑state indicator was derived by recognising acoustic signatures linked to air–sea interaction processes.

Findings were presented at major conferences, including MetroSea 2024 (Portorož), Euronoise 2025 (Málaga) and MetroSea 2025 (Genova), with several manuscripts submitted and others in preparation. The project also gained visibility within the national acoustics community through participation at the AIA Conference in Taormina, followed by an invitation to present at a dedicated session on 17 March 2026. SEAmPhonia further contributed to the field by serving as special session chair at MetroSea 2025 (Genova).

2. Technology

The technological work package focused on two main objectives: test synchronisation procedures for multiple hydrophones, calibrate commercial hydrophones, and co-design a low‑noise sensor with an industrial partner; and develop a new fibre‑optic system for 3D acoustic field acquisition. To this end, the team conducted a series of synchronisation tests using identifiable acoustic tones and carried out comprehensive calibrations in the CNR‑INM acoustics laboratory and at sea. These activities were supported by multi‑instrument data analysis and by ongoing laboratory validation of emerging fibre‑optic components, followed by initial tests in the field.

The work led to several important outcomes. Synchronisation tones were reliably detected across sensors, but the experiments also revealed time‑base drift in remote hydrophones and long‑term instability in certain acoustic emitters, linked to mechanical membrane limitations. These findings informed the recommendation to employ multiple emission sources to improve synchronisation robustness. The team also produced and compared detailed calibration curves, strengthening the reliability of the sensor network.

Results were presented at major events, including Euronoise 2025 (Málaga) and MetroSea 2025 (Genova), and contributed to the delivery of the project’s technical milestones. Additional exploratory activities included the proposal to use atomic force microscopes as cell‑scale hydrophones and the execution of a dedicated field experiment at Lake Bracciano to test emerging sensor technologies. Patent procedures have also been initiated in relation to the fibre‑optic developments.

3. Science‑to‑Policy Support

The science‑to‑policy component of SEAmPhonia aimed to strengthen the European contribution to the Marine Strategy Framework Directive (MSFD), with a specific focus on the Underwater Noise Descriptor. Activities included continuous engagement with key JPI Oceans initiatives—Science for Good Environmental Status (S4GES) and Underwater Noise in the Marine Environment—as well as participation in dedicated workshops with EU institutions and experts in marine acoustics. The project contributed to discussions on the integration of descriptors and the identification of emergent ecosystem properties.

Questo lavoro è stato presentato a livello europeo. L’approccio metodologico di SEAmPhonia è stato riconosciuto come innovativo, facilitando l’ingresso del team in reti strategiche di esperti. Il progetto ha proposto un cambio di paradigma nel monitoraggio del rumore sottomarino, promuovendo l’uso delle dinamiche relative in sostituzione dei tradizionali SPL fissi a 63–125 Hz, e l’inclusione di bande ad alta frequenza più sensibili ai segnali biologici. Tali contributi hanno portato a un invited talk alla conferenza JPI Oceans sul rumore sottomarino ad Alicante (2025), e i membri del team sono stati successivamente nominati advisor nel progetto JPI Oceans BluEcho.

The project also delivered several high‑visibility outputs, including the organisation of an international workshop in Gaeta (2024) involving MSFD TG Noise, JPI Oceans, industry stakeholders and scientists. Results were presented at S4GES in Brussels (2025) and at the Underwater Noise Conference in Alicante (2025), and were disseminated through a publication at MetroSea 2025 (Genova) titled “Acoustic Underwater Noise: the Segregation of Frequency Bands for Science‑to‑Policy Advise”.

Deliverables:

D1_PHYSICS_SPACE-TIME-DIAGRAM-TRADITIONAL: Space-time diagram from traditional hydrophones
D2_INSTRUMENT_FBG-DESIGN: Fibre-optic hydrophone design and implementation
D3_INSTRUMENT_FBG-MTF: Modulation transfer function of the fibre-optic hydrophone
D4_PHYSICS-SPACE-TIME-DIAGRAM-FBG: Space-time diagram from fibre-optic multiple-hydrophone station developed within the project
D5_INSTRUMENT_COMPARATIVE-ANALYSYS: Comparative analysis of data acquired with different sensors and configurations
D6_INSTRUMENT_ANCILLARY: Analysis of acquired data for different regimes with support of ancillary measurements
D7_MANAGEMENT_FEASIBILITY-STUDY: Feasibility study for an observational system with fibre-optic sensors and cost-benefit analysis
DN1_PHYSICS_TL: Transmission Loss Model
DN2_PHYSICS_NANO: Hydrophones calibration: an experimental approach to study the underwater acoustic field

Pubblicazioni:

P. F. Moretti, A. Pomaro and S. Buogo, “Metrology for Underwater Acoustics: Rethinking Measurement Strategies for the Assessment of the Environmental Status,” 2024 IEEE International Workshop on Metrology for the Sea; Learning to Measure Sea Health Parameters (MetroSea), Portorose, Slovenia, 2024, pp. 546-551, doi: 10.1109/MetroSea62823.2024.10765621
A. Pomaro, and P. F. Moretti, “Acoustic indicators of ecosystems’ and energy dynamics in marine environments,” in Proceedings of Forum Acusticum Euronoise 2025, Malaga, 2025
D. Nazarpour, P. F. Moretti, S. Buogo, & A. Pomaro, “Time synchronization of long-term underwater acoustic observations: the challenge of autonomous hydrophones without global clock baseline”, in Proceedings of Forum Acusticum Euronoise 2025, Malaga, 2025
A. Pomaro et al., “SEAmPhonia: a 3D acoustic field approach to marine ecosystem modelling,” 2025 IEEE International Workshop on Metrology for the Sea; Learning to Measure Sea Health Parameters (MetroSea), Genoa, Italy, 2025, pp. 442-447, doi: 10.1109/MetroSea66681.2025.11245768
P. F. Moretti and A. Pomaro, “Acoustic underwater noise: the segregation of frequency bands for science-to-policy advise,” 2025 IEEE International Workshop on Metrology for the Sea; Learning to Measure Sea Health Parameters (MetroSea), Genoa, Italy, 2025, pp. 448-453, doi: 10.1109/MetroSea66681.2025.11245668
P. F. Moretti, S. Buogo, and A. Pomaro, “Scale Invariance in the High-Frequency Marine Soundscape: Diel Oscillations as a Proxy for Ecosystem State,” Frontiers in Marine Science, (submitted)

Acnkowledgements:

The activities have been carried out in the framework of the PRIN 2022 Project “SEAmPhonia – An innovative enlightening approach to enable the modelling of marine ecosystems by the acoustic 3D field” (project code: 2022AWXT3K) funded by the European Union – Next Generation EU. We thank Nucleo Sommozzatori della Polizia di Stato of Venice for all underwater experimental installations at the AAOT and Istituto Nautico “G. Caboto” of Gaeta for their support under the project “Sustainable and Innovative Green Laboratories,” funded by ERDF PON 13.1.4A-LA-2022-28.