Remote sensing by unmanned aerial vehicles (UAVs) provides for obtaining large amounts of high-resolution data without direct intervention, which can be managed with geographic information systems (GIS). This allow spatial analysis of a habitat based on georeferenced data which is important to understand the structure and ecological distribution that are fundamental to ecosystems. Isla Arena (10°44ʹ20” N, 75°21ʹ10” W) is an inshore small shoal with a well-developed coral reef formation, despite the sedimentary influence of the Magdalena River in the Colombian Caribbean. Twenty years ago, habitat mapping of ecological units (EUs) of the area was carried out as a baseline study. In this study, we applied an analysis of remotely sensed aerial images, coupled with traditional in situ data to evaluate two different objectives. The first objective was to report the current ecological units in the reef formation with their respective distribution using a high-resolution orthophotomosaic to make a supervised classification based on the spectral reflectance of pixels and a spatial analysis of the reef formation. We evaluated 12 substrate components, of which eight were identified at the species level; then, seven EUs were defined in a thematic map. The second objective was to evaluate variations in the structure of the sessile community with underwater video transects to compare with a baseline study. We found that the coral cover remained similar but that seagrasses and zoanthids decreased in abundance, and macroalgae and sponge abundances increased, which could indicate reef degradation. The implementation of remote sensing by UAVs at Isla Arena was successful and provides a high-resolution alternative for describing the attributes of a shallow reef system. The comparison with the baseline study of the island allowed us to estimate the changes in the community structure and to update its EUs.

无人飞行器（UAV）的遥感技术可在无需直接干预的情况下获得大量高分辨率数据，这些数据可通过地理信息系统（GIS）进行管理。这样就可以根据地理参考数据对栖息地进行空间分析，这对于理解生态系统基本的结构和生态分布非常重要。尽管哥伦比亚马格达莱纳河的沉积影响，Isla Arena（北纬10°44 is20”，西经75°21ʹ10”）是一个沿海小滩，具有发达的珊瑚礁形成。二十年前，对该地区的生态单位（EU）进行栖息地制图已作为基线研究。在这项研究中，我们对遥感航空影像进行了分析，并结合了传统的原位数据来评估两个不同的目标。第一个目标是报告高分辨率礁石地层中的当前生态单元及其各自的分布，使用高分辨率的正光马赛克技术根据像素的光谱反射率和礁石地层的空间分析进行监督分类。我们评估了12种底物成分，其中有8种是在物种水平上鉴定的。然后，在主题图中定义了七个EU。第二个目标是使用水下视频样板评估无柄群落结构的变化，以与基线研究进行比较。我们发现，珊瑚的覆盖率仍然相似，但是海草和zoanthidids的丰度降低了，大型藻类和海绵的丰度提高了，这可能表明礁石退化了。无人机在Isla Arena的无人机实施成功，为描述浅礁系统的特性提供了高分辨率的替代方案。与该岛基线研究的比较使我们能够估计社区结构的变化并更新其欧盟。