Abstract：
Floating macroalgae of Sargassum horneri (S. horneri) in the East China Sea (ECS) has increased in recent years, with ocean warming being one of the driving factors. Yet their possible origins, based on a literature review, are unclear. Here, using multi-sensor high-resolution remote sensing data and numerical experiments for the period of 2015-2023, we show two possible origins of the ECS floating S. horneri, one being local near the Zhejiang coast with initiation in January-February and the other being remote (> 800 km from the first) in the Bohai Sea with initiation in June-November. While their drifting pathways are revealed in the sequential remote sensing imagery, numerical experiments suggest that S. horneri from the remote origin (Bohai Sea) can hardly meander through the strong Yangtze River frontal zone, which may serve as a \"wall\" to prevent trespassing of surface floating seaweed to the south of the frontal zone, where S. horneri has a local origin. PLAIN LANGUAGE SUMMARY: Sargassum horneri (S. horneri) is a brown macroalgae (seaweed) abundant in surface waters of the East China Sea (ECS), which can serve as a moving habitat, but can also cause major beaching events and environmental problems. Knowledge of its origins is important to help implement mitigation strategies and understand possible ecological impacts along its drifting pathways. Using high-resolution remote sensing images and numerical experiments, we track floating S. horneri in space and time between 2015 and 2023. Two possible origins are identified, one being far away from the ECS and the other being local, both of which are known to have benthic S. horneri. The study also reveals how S. horneri are transported from their source regions resulting in large-scale distributions previously observed in medium-resolution satellite imagery.
摘要：
马尾藻的漂浮大型藻类（S.horneri)在东海(ECS)近年来有所增加，海洋变暖是驱动因素之一。然而它们可能的起源，根据文献综述，不清楚。这里,使用2015-2023年期间的多传感器高分辨率遥感数据和数值实验，我们展示了ECS浮动S.horneri的两个可能起源，一个在浙江海岸附近，在1月至2月开始，另一个在渤海偏远（距离第一个海岸>800公里），在6月至11月开始。虽然在连续的遥感图像中揭示了它们的漂移路径，数值实验表明，来自遥远起源（渤海）的S.horneri几乎不能蜿蜒穿过强大的长江额叶带，这可以作为“墙”，以防止表面漂浮的海藻侵入额叶区南部，霍纳里有当地血统。简单语言摘要：Sargassumhorneri(S.horneri）是东海（ECS）地表水中丰富的棕色大型藻类（海藻），可以作为一个移动的栖息地，但也可能导致重大的搁浅事件和环境问题。了解其起源对于帮助实施缓解战略和了解其漂移路径可能产生的生态影响非常重要。利用高分辨率遥感影像和数值实验,我们在2015年至2023年之间在空间和时间上跟踪漂浮的S.horneri。确定了两个可能的起源，一个远离ECS，另一个是本地的，已知这两种都有底栖S.horneri。该研究还揭示了霍纳里是如何从源区域运输的，从而导致以前在中等分辨率卫星图像中观察到的大规模分布。
