Type-2 Fuzzy Deep Learning Framework for Robust Marine Species Identification Under Underwater Environmental Uncertainty

Authors

  • Masakapalli Chitti Naga Lakshmi
  • Dontula Kavya Latha Harshini
  • Manas Kumar Yogi

Keywords:

Deep learning, Karnik-Mendel type reduction, Marine species identification, Robust classification, Type-2 fuzzy logic, Underwater image uncertainty

Abstract

Underwater imagery is characterized by non-stationary optical noise, unpredictable turbidity, and inconsistent illumination that severely undermine the reliability of conventional deep learning classifiers used for marine species identification. This study proposes IT2F-AquaNet, an interval type-2 fuzzy deep learning framework that embeds a second layer of uncertainty modeling, termed the footprint of uncertainty, directly within a convolutional-transformer hybrid backbone to explicitly represent both aleatoric image noise and epistemic labeling ambiguity. The framework couples an adaptive preprocessing stage, an Interval Type-2 Fuzzy Logic System (IT2FLS) uncertainty module, a fuzzy feature-fusion layer employing Karnik-Mendel type reduction, and an uncertainty-aware attention classifier that outputs both a species label and a calibrated confidence band. The framework was evaluated on a composite benchmark built from multiple public underwater datasets augmented with simulated turbidity, illumination drift, and motion blur. Experimental results demonstrate that IT2F-AquaNet attains 93.8% classification accuracy and a macro F1-score of 92.9%, outperforming six state-of-the-art baselines by margins of 5.4 to 9.6 percentage points under degraded visual conditions. Ablation analysis confirms that the fuzzy uncertainty module contributes the largest performance gain among all architectural components. These findings position type-2 fuzzy-augmented deep architectures as a viable direction for dependable marine biodiversity monitoring systems.

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Published

2026-09-17