AQUA20: A Benchmark Dataset for Underwater Species Classification under Challenging Conditions
摘要
Robust visual recognition remains a significant challenge in underwater environments due to complex distortions such as turbidity, low illumination, and occlusion, which severely degrade the performance of standard vision systems. This study introduces AQUA20, a dataset comprising 8,171 images of 20 ecologically significant marine species. AQUA20 provides greater multi-species diversity and real-world variability than other public datasets, such as Fish4Knowledge and WildFish, which are limited in terms of taxonomic scope or environmental complexity. We benchmarked this dataset by evaluating models ranging from lightweight CNNs suitable for edge deployment (e.g., SqueezeNet and MobileNetV2) to modern vision transformers (e.g., ViT and ConvNeXt) for marine species classification under challenging conditions. ConvNeXt achieved the best performance, with a Top-3 accuracy of 98.82% and Top-1 accuracy of 90.69%, as well as the highest overall F1-score of 88.92%. The results include the trade-offs between complexity and performance. We also provide an extensive explainability analysis using GRAD-CAM and LIME to interpret the strengths and pitfalls of the models, which further reveals that high-performing models focus on biologically relevant features, whereas lower-performing models are distracted by background noise, providing a clear pathway for future improvements in the model architectures. The dataset is publicly available at: https://huggingface.co/datasets/taufiktrf/AQUA20.