Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

The Status of Amazonian Manatees (Trichechus inunguis) and Their Habitats in Eastern Ecuador

Event Name/Location

19th Biennial Conference on the Biology of Marine Mammals, Tampa, Florida, November 27-December 2, 2011

Presentation Date


Document Type

Conference Proceeding


The purpose of this investigation was to determine the current population status of Amazonian manatees (Trichechus inunguis) and their habitat in eastern Ecuador. Threats to this endangered species include oil exploration and extraction, water pollution, subsistence hunting, and incidental mortality. Our methods included side scanning sonar surveys of the Amazon River and tributaries in eastern Ecuador, interviews with local residents, and analysis of water samples using Environmental Protection Agency (EPA) methods. Data collection will be in progress until the first of August. Sonar surveys were recorded and further analyzed for evidence of manatees. Forty possibIe manatee detections were identified. There were two visual sightings and thirty-eight sonar sightings. This is evidence that manatees persist in Amazonian Ecuador but are very rare. Upon completion of data collection, the population data will be analyzed using patch occupancy models. Interviews were conducted with local residents who live on the rivers and tributaries and have direct contact with the animals. Hundreds of manatee sightings were reported. It was noteworthy how many people had hunted and eaten these creatures. Many locals had multiple harpoons specifically for hunting manatees. Water samples were analyzed to determine the concentrations of fecal coliform bacteria, polyaromatic hydrocarbons (pAHs), volatile organics, toxic metals, mercury, and petroleum hydrocarbons in samples collected while conducting manatee surveys. All samples contained varying concentrations of crude oil with 30-40 carbons and both total and fecal coliforms, but no evidence of toxic PAHs, metals, or volatile organics has been found currently. This suggests that the oil development in the Orellana region of Ecuador is not directly impacting the habitat of Trichechus inunguis. We conclude that the most notable threat to the sustainability of the Trichechus inunguis population in eastern Ecuador is hunting,


©Society for Marine Mammalogy

This document is currently not available here.