The sentinel sea cow
29 Oct 2012 by Evoluted New Media
Manatees may reflect the quality of health in marine ecosystems according to a long-term, collaborative study led by George Mason University, published in PLOS ONE.
The research, which was conducted over ten years in Belize, investigated the health, behavioural ecology and life history of manatees in an area relatively undisturbed by humans.
"Manatees are the proverbial 'canaries in the mineshaft,' as they serve as indicators of their environment and may reflect the overall health of marine ecosystems," said Alonso Aguirre, executive director of the Smithsonian-Mason School of Conservation.
Aguirre refers to manatees as a “sentinel species” meaning that they are early warning indicators of environmental change. Manatees may be highly susceptible or highly resistant to different environmental stresses and can indicate a severe environmental change before other species in the ecosystem are affected.
"Studying them may help us predict a change that has the potential to be devastating to an ecosystem or a habitat if left unaddressed," Aguirre said.
The study was conducted in a small fishing community in southern Belize which was a relatively pristine area with low human influence but is beginning to gain more tourists.
The team were focusing on the systemic health threats to marine vertebrate species as they relate to marine ecological health. They captured the manatees to tag and track them before releasing them back to their habitats. They conducted health assessments, taking ultrasonic fat measurements, blood biochemistry, faecal and urine analyses. Between 1997 and 2009, the team collected around 200 blood samples and aerial surveys were conducted twice a year to monitor population numbers.
"This longterm study, unique within marine mammals, provides insight on the baseline health of this species now threatened primarily by human encroachment, poaching and habitat degradation. This study is a benchmark aiding in early disease detection and the current environmental impacts affecting the epidemiologic patterns in the manatees of this region,” added Aguirre.
Future goals for the researchers are to improve the conservation plan of the manatees, extend protection of migratory paths and educate local people and tourists about the importance of conservation.
