African Manatee Conservation

Abstract

The West African manatee, Trichechus senegalensis, ranges from Senegal in the north, to Angola in the south. Early works by Derscheid, an explorer of the Congo and sirenian enthusiast, and Bouveignes, describe manatees as living in the Chari, Bamingui, and Bahr-Kieta rivers which flow from the southeastern border of Chad into Lake Chad2,3. The existence of these populations has not been verified, and results from a recent survey show that they are likely extinct. The same survey, undertaken by the author in 1995, verified the existence of a seasonally isolated manatee population residing in lakes Léré and Tréné in the Mayo-Kebbi river on the southwest border of Chad. The lakes are at the northeastern tip of the Niger river drainage basin. Thus they are over one thousand miles from the ocean, at the edge of the Sahara desert. It has been postulated that the manatees arrived here from the ocean by navigating the busy Niger and Benué rivers, seeking solace in the sparsely populated lakes which are part of the Mayo-Kebbi river system.11 The fact that the existence of this population had not been previously documented12, can probably be attributed to the remote nature of the lakes, and the unstable political climate in Chad. The exact number and status of these animals has yet to be determined. However, it is clear that they are currently suffering from the detrimental effects of unchecked hunting practices and habitat destruction. Findings also indicate that the manatee population has been declining in recent years.13

The local population is predominantly made up of members of the Moundang tribe, whose chief, or gong, is the most powerful traditional figure in the lakes region. A great deal of Moundang folklore and tradition is built around their interactions with the manatee. They are concerned with the manatee's future and feel that the animal plays an integral role in their cultural identity. Manatee oil is highly prized for its alleged effectiveness as a traditional curative. Sales of this oil can generate substantial income for the impoverished Chadian people. The intentional killing of a mantee is highly illegal in Chad. A branch of the Chadian Ministry of the Environment, known as the Parcs Nationaux Reserves de Faune, is responsible for the enforcement of anti-poaching laws. While well intentioned, this organization lacks the manpower and resources necessary to effectively handle this problem.13

This work represents the third phase of an ongoing study of the Chadian manatee population. Results from phase one in 1995, and phase two in 1996, indicated a desire by the local populace, and government agencies, to begin a conservation program. While interview results have provided a great deal of anecdotal information concerning the Chadian manatees, analysis of portions the mitochondrial genome (mtDNA) can lend objectivity towards the understanding of population parameters. Mitochondrial DNA sequences can be interpreted to examine effective population size, genetic isolation, gene flow, population structure, mutation rate, and genetic variation. Reduction in genetic variation can result in increased disease susceptibility, increased juvenile mortality, and decreased fertility.1 Results may also indicate the presence of an inland subspecies of the T. senegalensis. The existence of subspeciation between inland and coastal populations of West African manatees is often claimed by Africans, but has been refuted by morphological studies.4,12

Combining the knowledge gleaned from preliminary surveys, it was deemed that an effective approach towards manatee conservation in Chad would benefit from the combination of villagebased education and the collection of objective scientific data through mtDNA analysis. Other manatee conservation efforts in West Africa have utilized village and school based educational programs focusing on the protection of manatees and their wetland habitat.10 Mitochondrial DNA analysis is currently the method of choice for the genetic examination of population parameters of the West indian and Amazonian manatees, T. manatus and T. Inunguis respectively.5 This work represents the first attempt to examine the genetics of the West African manatee, T. senegalensis.7,14

Materials and Methods

Village Based Education

Educational seminars were developed based on conservation and biological aspects of West African manatees. Most of this work was completed in the United States by the author. Upon arrival in Chad, meetings were held with governmental and traditional authorities, scientists, educators, manatee hunters, and fishermen. These meetings were integral to the development of a village based pedagogy.

Two seminars were held in a representative villages on both lakes. At both sites the group comprised approximately fifty people including members of the local fishing consortium APRODEPIT, local educators, traditional chiefs, students, a US Peace Corps volunteer, and a representative of the government. Seminar topics included, but were not limited to:

-basic manatee anatomy and physiology with
an emphasis on reproduction,8
-effective population size,
-the concept of keystone species,
-ecotourism,
-inbreeding and genetic variation,
-subungulate phylogeny,
-the social and political aspects of manatee
hunting in Chad,
-the importance of social action to manatee
preservation,
-the role of Les Amis du Lamantin (The
Friends of the Manatee).

Whenever possible, local traditions and practices were used to illustrate concepts. The seminars were entirely interactive and local educators attended in preparation for facilitating future seminars in other villages.

A club, aptly named Les Amis du Lamantin, was formed by the local populace just prior to the author's arrival in Chad. The club had a name and a list of members but had not determined what they were going to do nor how they would accomplish it. The services of the author were enlisted to develop the club's purposes and methods. Daily meetings were held with founding members and objectives and methods were developed. These were written down in the form necessary for presentation to the Chadian government to become an accepted NGO (Non-Governmental Organization).

Members were recruited and the first official meeting was held. At this meeting it was decided that the major objectives of the club would be education of the local villagers about manatee conservation, and observation of activities concerning manatees. A second meeting was scheduled to elect an administrative council and discuss the next step in completing the objectives.

A conference was also held at the Centre National d'Appui à la Rechérche (CNAR) in the capital city, N'Djamena. It was presented by the author as well as a representative of the Parcs Nationaux et Réserves du Faune. This represented the first public meeting ever held concerning the manatee population in Chad. The idea behind the conference was to raise awareness among high-level government officials, the international donor community, scientists, university students, and the press. It also functioned as a means of promoting the cause and acceptance of the Léré based conservation club.