Real-Time Dolphin Whistle Detection on Raspberry Pi Zero 2 W with a TFLite Convolutional Neural Network

The escalating conflict between cetaceans and fisheries underscores the need for efficient mitigation strategies that balance conservation priorities with economic viability. This study presents a TinyML-driven approach deploying an optimized Convolutional Neural Network (CNN) on a Raspberry Pi Zero...

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Main Authors: Rocco De Marco, Francesco Di Nardo, Alessandro Rongoni, Laura Screpanti, David Scaradozzi
Format: Article
Language:English
Published: MDPI AG 2025-05-01
Series:Robotics
Subjects:
Online Access:https://www.mdpi.com/2218-6581/14/5/67
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author Rocco De Marco
Francesco Di Nardo
Alessandro Rongoni
Laura Screpanti
David Scaradozzi
author_facet Rocco De Marco
Francesco Di Nardo
Alessandro Rongoni
Laura Screpanti
David Scaradozzi
author_sort Rocco De Marco
collection DOAJ
description The escalating conflict between cetaceans and fisheries underscores the need for efficient mitigation strategies that balance conservation priorities with economic viability. This study presents a TinyML-driven approach deploying an optimized Convolutional Neural Network (CNN) on a Raspberry Pi Zero 2 W for real-time detection of bottlenose dolphin whistles, leveraging spectrogram analysis to address acoustic monitoring challenges. Specifically, a CNN model previously developed for classifying dolphins’ vocalizations and originally implemented with TensorFlow was converted to TensorFlow Lite (TFLite) with architectural optimizations, reducing the model size by 76%. Both TensorFlow and TFLite models were trained on 22 h of underwater recordings taken in controlled environments and processed into 0.8 s spectrogram segments (300 × 150 pixels). Despite reducing model size, TFLite models maintained the same accuracy as the original TensorFlow model (87.8% vs. 87.0%). Throughput and latency were evaluated by varying the thread allocation (1–8 threads), revealing the best performance at 4 threads (quad-core alignment), achieving an inference latency of 120 ms and sustained throughput of 8 spectrograms/second. The system demonstrated robustness in 120 h of continuous stress tests without failure, underscoring its reliability in marine environments. This work achieved a critical balance between computational efficiency and detection fidelity (F1-score: 86.9%) by leveraging quantized, multithreaded inference. These advancements enable low-cost devices for real-time cetacean presence detection, offering transformative potential for bycatch reduction and adaptive deterrence systems. This study bridges artificial intelligence innovation with ecological stewardship, providing a scalable framework for deploying machine learning in resource-constrained settings while addressing urgent conservation challenges.
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spelling doaj-art-11515f4ebc2d42e78f564b05135ef1d42025-08-20T01:56:39ZengMDPI AGRobotics2218-65812025-05-011456710.3390/robotics14050067Real-Time Dolphin Whistle Detection on Raspberry Pi Zero 2 W with a TFLite Convolutional Neural NetworkRocco De Marco0Francesco Di Nardo1Alessandro Rongoni2Laura Screpanti3David Scaradozzi4Institute of Biological Resources and Marine Biotechnology (IRBIM), National Research Council (CNR), 60125 Ancona, ItalyDipartimento di Ingegneria Dell’Informazione, Università Politecnica delle Marche, 60131 Ancona, ItalyDipartimento di Ingegneria Dell’Informazione, Università Politecnica delle Marche, 60131 Ancona, ItalyDipartimento di Ingegneria Dell’Informazione, Università Politecnica delle Marche, 60131 Ancona, ItalyDipartimento di Ingegneria Dell’Informazione, Università Politecnica delle Marche, 60131 Ancona, ItalyThe escalating conflict between cetaceans and fisheries underscores the need for efficient mitigation strategies that balance conservation priorities with economic viability. This study presents a TinyML-driven approach deploying an optimized Convolutional Neural Network (CNN) on a Raspberry Pi Zero 2 W for real-time detection of bottlenose dolphin whistles, leveraging spectrogram analysis to address acoustic monitoring challenges. Specifically, a CNN model previously developed for classifying dolphins’ vocalizations and originally implemented with TensorFlow was converted to TensorFlow Lite (TFLite) with architectural optimizations, reducing the model size by 76%. Both TensorFlow and TFLite models were trained on 22 h of underwater recordings taken in controlled environments and processed into 0.8 s spectrogram segments (300 × 150 pixels). Despite reducing model size, TFLite models maintained the same accuracy as the original TensorFlow model (87.8% vs. 87.0%). Throughput and latency were evaluated by varying the thread allocation (1–8 threads), revealing the best performance at 4 threads (quad-core alignment), achieving an inference latency of 120 ms and sustained throughput of 8 spectrograms/second. The system demonstrated robustness in 120 h of continuous stress tests without failure, underscoring its reliability in marine environments. This work achieved a critical balance between computational efficiency and detection fidelity (F1-score: 86.9%) by leveraging quantized, multithreaded inference. These advancements enable low-cost devices for real-time cetacean presence detection, offering transformative potential for bycatch reduction and adaptive deterrence systems. This study bridges artificial intelligence innovation with ecological stewardship, providing a scalable framework for deploying machine learning in resource-constrained settings while addressing urgent conservation challenges.https://www.mdpi.com/2218-6581/14/5/67TinyMLdolphin whistle detectionconvolutional neural network (CNN)TensorFlow LiteRaspberry Pi
spellingShingle Rocco De Marco
Francesco Di Nardo
Alessandro Rongoni
Laura Screpanti
David Scaradozzi
Real-Time Dolphin Whistle Detection on Raspberry Pi Zero 2 W with a TFLite Convolutional Neural Network
Robotics
TinyML
dolphin whistle detection
convolutional neural network (CNN)
TensorFlow Lite
Raspberry Pi
title Real-Time Dolphin Whistle Detection on Raspberry Pi Zero 2 W with a TFLite Convolutional Neural Network
title_full Real-Time Dolphin Whistle Detection on Raspberry Pi Zero 2 W with a TFLite Convolutional Neural Network
title_fullStr Real-Time Dolphin Whistle Detection on Raspberry Pi Zero 2 W with a TFLite Convolutional Neural Network
title_full_unstemmed Real-Time Dolphin Whistle Detection on Raspberry Pi Zero 2 W with a TFLite Convolutional Neural Network
title_short Real-Time Dolphin Whistle Detection on Raspberry Pi Zero 2 W with a TFLite Convolutional Neural Network
title_sort real time dolphin whistle detection on raspberry pi zero 2 w with a tflite convolutional neural network
topic TinyML
dolphin whistle detection
convolutional neural network (CNN)
TensorFlow Lite
Raspberry Pi
url https://www.mdpi.com/2218-6581/14/5/67
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