Replication Data for \"High abundance of macroplastic on a sea turtle nesting beach at the Pacific coast of Central America\"

Abstract of Manuscript: Plastic pollution poses a growing threat to coastal ecosystems, including sea turtle nesting habitats, yet data from Central America remains scarce. We quantified and mapped macroplastic (> 5mm) pollution on an Olive Ridley (Lepidochelys olivacea) nesting beach along the Pacific coast of Guatemala by applying both unmanned aerial vehicle (UAV) surveys and ground-based monitoring. We mapped macroplastic items using the OSPAR (Oslo and Paris Convention) beach litter protocol for both UAV imagery and systematic ground-truthing within representative grids. We analyzed plastic abundance with negative binomial mixed-effects models, accounting for sampling method, beach level, and vegetation presence. Ground-truthing revealed a total of 12,297 macroplastic items, corresponding to an average of 2,102 items per 100m shoreline, exceeding the OSPAR beach litter threshold 100 times. Most plastic originated from land-based sources, with accumulation near the high-tide line and within vegetated beach zones- areas that overlap with preferred sea turtle nesting habitat. Ground-based surveys consistently detected substantially higher plastic abundances than UAV imagery, particularly in vegetated areas, where aerial detection was limited. However, the integration of UAVs with ground-truth interpolation facilitated large-scale beach coverage. This study provides the first systematic assessment of macroplastic pollution on Guatemala’s Pacific coast. It highlights both the severity of plastic contamination on a sea turtle nesting beach and the need for pollution monitoring, and it emphasizes the trade-offs between detection accuracy and survey efficiency. Integrating ground surveys with aerial methods offers a scalable approach for identifying pollution hotspots and informing coastal management and conservation strategies in data-poor regions.论文摘要：塑料污染对包括海龟筑巢栖息地在内的沿海生态系统构成日益严峻的威胁，但中美洲地区的相关监测数据仍较为匮乏。本研究针对危地马拉太平洋沿岸的一处丽龟（Lepidochelys olivacea）筑巢海滩，通过结合无人驾驶航空器（unmanned aerial vehicle, UAV）航拍与地面验证（ground-truthing）手段，对粒径>5mm的大塑料（macroplastic）污染情况开展量化与空间制图。研究采用奥斯陆与巴黎公约（OSPAR, Oslo and Paris Convention）海滩垃圾规程，分别针对无人机影像与代表性网格内的系统地面验证结果进行大塑料垃圾的点位标注与制图。本研究采用负二项混合效应模型（negative binomial mixed-effects models）分析塑料丰度，同时将采样方法、海滩高程以及植被覆盖情况纳入模型作为控制变量。地面验证共检出12297件大塑料垃圾，对应每100米海岸线平均分布2102件垃圾，超出OSPAR海滩垃圾阈值达100倍。绝大多数塑料垃圾来自陆源，且在高潮线附近与植被覆盖海滩带——即海龟偏好的筑巢栖息地重叠区域——发生富集。地面调查检出的塑料丰度始终显著高于无人机航拍结果，在植被覆盖区域这一差异尤为突出，该区域的空中探测存在明显局限。但将无人机技术与地面实测插值相结合，可实现海滩区域的大范围覆盖。本研究是首次对危地马拉太平洋沿岸的大塑料污染开展系统性评估。研究既揭示了海龟筑巢海滩塑料污染的严峻程度，凸显了污染监测工作的必要性，同时也强调了探测精度与调查效率之间的权衡关系。将地面调查与航拍手段相结合，可为数据匮乏地区的污染热点区域识别、沿海管理与保护策略制定提供可规模化推广的解决方案。