WADE: A Reasoning-Annotated Benchmark for Multi-Instance Floating-Waste Grounding with Compact Vision-Language Models
Organizations: United International University
Abstract
Floating waste in inland waterways threatens aquatic ecosystems and requires timely monitoring under cluttered, multi-object conditions. Existing aquatic-waste datasets provide limited geographic coverage, sparse multi-instance annotations, and little supervision beyond boxes and labels. Compact vision-language models (VLMs) therefore remain insufficiently evaluated for jointly localizing, classifying, counting, and explaining floating waste. We introduce WADE, a reasoning-annotated benchmark containing 2,167 images from rural Bangladesh, 13,608 bounding boxes, and ten waste categories. Each annotation is associated with class-level recognition rules covering visual cues, likely confusions, and discriminative features. We evaluate six VLMs under zero-shot, two-shot, reasoning-guided, and fine-tuned settings using detection, counting, and hallucination metrics. For resource-efficient adaptation, we jointly fine-tune Qwen3-VL-2B on boxes, labels, and reasoning chains using QLoRA. Fine-tuning increases recall from 0.0248 to 0.2339 and F1 from 0.0257 to 0.2163, while reducing image-level hallucination from 0.6836 to 0.0883. However, over three-quarters of instances remain undetected, establishing WADE as a challenging benchmark for dense floating-waste grounding with compact VLMs.
Figures & tables
| Class | N | % | Class | N | % |
| Water hyacinth | 2,137 | 15.7 | Algal bloom | 1,110 | 8.2 |
| Plastic bottle | 1,933 | 14.2 | Solid waste | 1,008 | 7.4 |
| Organic waste | 1,605 | 11.8 | Fabric waste | 976 | 7.2 |
| Industrial waste | 1,563 | 11.5 | Wood debris | 887 | 6.5 |
| Polythene | 1,525 | 11.2 | Foam waste | 864 | 6.3 |
| Images: 2,167 | Mean: 6.28 instances/image | ||||
| Grounding | Hallucination | Counting Error | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Regime | Model | ||||||||||
| Zero-shot | LLaMA-3.2-11B | .0070 | .0066 | .0068 | .0123 | .0027 | .94 | .7621 | .9839 | 2.187 | 3.610 |
| Zero-shot | InternVL2-2B | .0022 | .0046 | .0030 | .0043 | .0000 | 2.09 | .8639 | .9960 | 4.325 | 5.232 |
| Zero-shot | Qwen3-VL-2B | .0267 | .0248 | .0257 | .0347 | .0107 | .93 | .6722 | .6836 | 2.540 | 3.889 |
| Zero-shot | LFM2.5-VL-1.6B | .0031 | .0048 | .0043 | .0110 | .0019 | 1.55 | .8374 | .5291 | 3.430 | 5.739 |
| Zero-shot | GPT-4o-mini | .0339 | .0153 | .0211 | .0293 | .0013 | .45 | .5817 | .4679 | 1.954 | 3.597 |
Appendix figures & tables3 assets
Supplementary material from the paper’s appendix.
Appendix
| Hyperparameter | Value |
|---|---|
| Base model | Qwen3-VL-2B-Instruct |
| Quantization | 4-bit NF4 |
| LoRA rank | 16 |
| LoRA | 32 |
| LoRA dropout | 0.05 |
| Epochs | 3 |
| Regime | Model | Box | Reason. | Halluc. |
|---|---|---|---|---|
| Zero-shot | InternVL2-2B | 2.1 | 4.0 | 2.5 |
| Zero-shot | LLaMA-3.2-11B | 3.0 | 5.5 | 2.6 |
| Zero-shot | Qwen3-VL-2B | 3.6 | 6.5 | 3.8 |
| Zero-shot | GPT-4o-mini | 3.9 | 7.0 | 5.1 |
| Zero-shot | Gemini-2.5-Flash | 4.1 | 7.8 | 4.2 |
| Reasoning | Qwen3-VL-2B | 4.3 | 8.0 | 5.8 |
| Regime | Model | Box | Reason. | Halluc. |
|---|---|---|---|---|
| Zero-shot | InternVL2-2B | 1.5 | 3.5 | 2.5 |
| Zero-shot | LLaMA-3.2-11B | 3.0 | 4.0 | 3.5 |
| Zero-shot | Qwen3-VL-2B | 4.0 | 5.5 | 3.5 |
| Zero-shot | GPT-4o-mini | 4.5 | 6.0 | 6.5 |
| Zero-shot | Gemini-2.5-Flash | 5.0 | 7.0 | 6.5 |
| Reasoning | Qwen3-VL-2B | 4.5 | 6.0 | 4.5 |
Vision-Language Grounding
Vision-Language Grounding links words and phrases to the objects, regions, actions, or moments they describe in images, video, and scenes.
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