2012 COURSE DATES: AUGUST 4 – 17, 2012 - Sirenian International

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examined trends in manatee abundance from 2001-2007. Through simulations, we
conducted a power analysis to determine trend detection ability and the ramifications of
sampling structure on trend detection.
2. Materials and Methods
2.1 Study area
The Drowned Cayes, including Swallow Caye, are a string of mangrove islands -14 km
long by 4 km wide - along the central coast of Belize, 10-15 km east of Belize City and 3-5
km west of the Belize Barrier reef (Figure 1). These islands are surrounded by shallow
seagrass beds. The depth of the study area is less than 1 meter in some places and is never
greater than 6 meters. The study area also encompasses two points along the Belize Barrier
Reef. Prior to this study, aerial and boat surveys and DNA analyses documented that this
area has an important population of manatees (Auil 2004; Bengston and Magor 1979;
Hunter et al. 2010; LaCommare et al. 2008, Morales-Vela et al. 2000; O'Shea and Salisbury
1991, Self-Sullivan 2008).
This study area is typical of manatee coastal habitat making it appropriate for
testing our survey protocol. It comprises: shallow water (1-3m deep), proximity to deeper
channels (3-6 m) for escape from danger (boats), freshwater sources, aquatic vegetation
(mostly submerged), warm water (17°C minimum temperature), shelter from storms,
waves, strong winds and currents; and travel corridors between habitat areas (Moraes-
Arraut et al. in press).
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