Researchers assessed changes as human activity grew in a remote Belize coastal area
By Summit Voice
FRISCO — Results of a long-term manatee study in Belize suggest the gentle marine mammals are a true sentinel species, indicating overall ecosystem health of coastal areas.
The research will help strengthen manatee conservation plans, showing the importance of protecting habitat and migratory paths, and working with local populations as well as tourists to educate them about conservation activities.
“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 co-author Alonso Aguirre, executive director of the Smithsonian-Mason School of Conservation.
Aguirre calls them a “sentinel species,” which means they are early warning indicators of environmental change. Because they may be highly susceptible or highly resistant to different environmental stressors, manatees can indicate a severe environmental change before other species or humans 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 says.
The study was conducted in a small fishing community in southern Belize that is beginning to prosper and gain more tourists in southern Belize. It documented changes in a relatively pristine area. Researchers saw the effects as human activity increased with more stress, boat strikes and other changes occurring as time went on.
Researchers like Aguirre are focusing on discovering the systemic health threats to marine vertebrate species, including marine mammals, as they relate to marine ecological health. There has been an unprecedented number of emerging and re-emerging diseases in dolphins, coral reefs and marine turtles in recent years.
“The single species approach may provide a series of “snapshots” of environmental changes to determine if animal, human or ecosystem health may be affected,” Aguirre said.
The researchers captured the animals to tag and track them before releasing them back to their habitats. Health assessments were conducted based on clinical exams, ultrasonic fat measurements, hematology, blood biochemistry, and urine and fecal analyses. The team was able to collect close to 200 blood samples between 1997 and 2009. In addition, aerial surveys by helicopter 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,” said Aquirre, who is also a professor in the Department of Environmental Science and Policy at George Mason University, said.
The research paper was published recently in PLoS One journal, in collaboration with scientists of University of California-Davis, USGS and Sea to Shore Alliance.