The Mexican Caribbean and Belize are home to one of the largest populations of Caribbean manatees (Trichechus manatus manatus). However, the transboundary Hondo River estuary is less examined compared to the surrounding protected areas. This paper provides a quantitative description of the spatial and temporal variability in abiotic factors and manatee distribution throughout the Hondo River estuary, with monthly field measurements during 2018–2019. Simultaneously, visual observations and side-scan sonar detection were implemented, with 84 manatee sightings reported (calves 11.9%, noncalves 88.1%). Heatmap and frequency analyses showed that most manatee sightings occurred at the riverine estuary limit, the confluences between the river and the bay into which it flows. The surface water temperature and salinity ranged 28°C ≤ T ≤ 32°C and 0.5 PSU ≤ S ≤ 4.5 PSU for ~72% of the manatees identified, potentially describing locally preferred conditions for manatees. During the regional mid-summer drought, higher temperature (31.5°C), salinity (18 PSU), and estuary extent (17.6 km) were recorded, including the maximum peak of manatee sightings (~31%). The roles of these abiotic factors are discussed as tentative environmental comfort conditions for manatees that could reduce their energy and maintenance costs. The identification of preferred conditions could broaden perspectives on how manatees interact with their habitats.

中文翻译：

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墨西哥-伯利兹河口地表水温和盐度的空间和季节变化：海牛可能的舒适条件？

墨西哥加勒比海地区和伯利兹是加勒比海海牛数量最多的地区之一（Trichechus manatus manatus）。然而，与周围的保护区相比，跨界洪多河河口的检查较少。本文通过 2018-2019 年的月度实地测量，定量描述了整个 Hondo 河口的非生物因素和海牛分布的时空变异性。同时，实施了目视观察和侧扫声纳检测，报告了 84 只海牛目击事件（小牛 11.9%，非小牛 88.1%）。热图和频率分析表明，大多数海牛目击事件发生在河口边界，即河流与其流入的海湾之间的汇合处。地表水温度和盐度范围为 28°C ≤ T ≤ 32°C 和 0.5 PSU ≤ S ≤ 4.5 PSU 对于约 72% 的海牛，可能描述了当地海牛的首选条件。在区域性仲夏干旱期间，记录了更高的温度 (31.5°C)、盐度 (18 PSU) 和河口范围 (17.6 公里)，包括海牛目击的最大峰值 (~31%)。这些非生物因素的作用被讨论为海牛的暂定环境舒适条件，可以降低它们的能源和维护成本。确定首选条件可以拓宽海牛如何与其栖息地相互作用的视角。