Manatee Synoptic Survey Observation Locations

The word “synoptic” means presenting a general view of the whole. The current manatee synoptic survey is a count of manatees over a broad area. The Florida Fish and Wildlife Conservation Commission (FWC) uses these surveys to obtain a general count of manatees statewide. The FWC coordinates an interagency team that conducts the synoptic surveys from one to three times each year (weather permitting). The synoptic surveys are conducted in winter and cover all of the known wintering habitats of manatees in Florida. The survey is conducted to meet Florida state statute 370.12 (4), which requires an annual, impartial, scientific benchmark census of the manatee population. From 1991 through 2019, the counts have been conducted 33 times. These statewide, interagency surveys are currently conducted during the coldest weather of the year (January through March) when manatees move to warm-water sites, such as natural springs, thermal discharges from power and industrial plants, and deep canals. The ideal conditions for the current synoptic survey are cool weather, following a prolonged period of cold weather (usually following multiple cold fronts), low winds, and bright sunshine. Weather conditions and manatee behavior during the survey have a large effect on the synoptic counts. For that reason, the counts are used as indicators of relative abundance within a year and are not suitable for assessing long-term population trends. Counts can vary depending on whether it is warm or cold, sunny or cloudy, calm or windy. Manatees are more easily counted a few days after a cold front when it is slightly warmer, clear, and windless. A warming trend with sunny, windless conditions following cold weather increases the likelihood that manatees will be resting at the water's surface, where observers can easily spot them.‘概览式（synoptic）’一词意为呈现整体的全面概览。当前开展的海牛概览式调查，即对大范围区域内的海牛进行计数统计。佛罗里达鱼类和野生动物保护委员会（Florida Fish and Wildlife Conservation Commission，简称FWC）借助此类调查获取全州范围内海牛的总体数量。FWC协调跨部门团队开展概览式调查，每年开展1至3次（视天气条件而定）。此类调查于冬季进行，覆盖佛罗里达州内所有已知的海牛越冬栖息地。开展本调查是为了符合佛罗里达州法规第370.12条第(4)款的要求，该条款要求对海牛种群开展年度、公正的科学基准普查。1991年至2019年间，此类全州跨部门调查共计开展33次。目前此类调查于每年最冷时段（1月至3月）开展，此时海牛会迁移至温暖水域，例如天然泉眼、电力及工业设施的热排放水域以及深运河。本次概览式调查的理想条件为：经历长期低温（通常伴随多股冷锋过境）后的凉爽天气、低风速以及晴朗日照。调查期间的天气条件与海牛行为会对概览式调查的计数结果产生显著影响。因此，此类计数仅可作为年度内海牛相对丰度的指示指标，并不适用于评估海牛种群的长期变化趋势。计数结果会随天气冷暖、晴阴、风速大小产生波动。在冷锋过境数日后，天气略微转暖、晴朗无风时，海牛更易被计数。低温天气过后出现晴朗无风的回暖趋势，会提升海牛在水面休憩的概率，便于观测者识别。