Environmental Monitoring and Genetic Identification of Freshwater Fish Species Enable the Conservation of Biodiversity in Coastal Rivers of Tanzania

This policy brief summarizes the findings of a recent study conducted by the University of Dar es Salaam’s School of Aquatic Sciences and Technology, in partnership with the Tanzania Fisheries Research Institute (TAFIRI) and the Thünen Institute of Fisheries Ecology in Germany. The study aimed at assessing and conserving fish biodiversity in two Tanzanian coastal rivers. In addition to a taxonomic analysis of fisheries catches in different parts of the rivers, the distribution and abundance of diadromous freshwater eels of the genus Anguilla was used as an indicator for environmental quality. To assess was used as an indicator for environmental quality. To assess habitat specific fish species composition, distribution, and abundance in the Rufiji and Pangani rivers, the team employed a combination of fishers’ ecological knowledge and biological science methods. Two freshwater eel species, Anguilla bicolor and Anguilla bengalensis, were found in the Rufiji riverine system, while the Pangani River had three species: A. bicolor, A. bengalensis, and A. marmorata. It was the first time that Anguilla marmorata was recorded in Tanzania. The taxonomic analysis of fisheries catches revealed gaps and inconsistencies in the knowledge and understanding of the fish fauna in Tanzania. Habitat quality differed considerably along the rivers due to different anthropogenic impacts. The findings underscore the need for long-term environmental monitoring, control of threats such as agriculture and overfishing, diversification of livelihoods, and the implementation of collaborative fisheries management and conservation measures. The study suggests that ecotourism could be a measures. The study suggests that ecotourism could be a potential solution to these issues.