The Endemic Species Flock of Labeobarbus spp. in L. Tana (Ethiopia) Threatened by Extinction: Implications for Conservation Management
Department of Animal Science and Aquatic Ecology, University of Ghent, 9000 Ghent, Belgium
Department of Fisheries, Wetlands and Wildlife Management, Bahir Dar University, Bahir Dar 6000, Ethiopia
Department of Zoological Sciences, Addis Ababa University, Addis Ababa 1000, Ethiopia
Department of Biology, Bahir Dar University, Bahir Dar 6000, Ethiopia
Food and Agriculture organization, Addis Ababa 1000, Ethiopia
Author to whom correspondence should be addressed.
Water 2019, 11(12), 2560; https://doi.org/10.3390/w11122560
Received: 5 November 2019 / Revised: 28 November 2019 / Accepted: 2 December 2019 / Published: 4 December 2019
(This article belongs to the Special Issue Sustainable Development of Lakes and Reservoirs)
The endemic Labeobarbus species in Lake Tana are severely affected by anthropogenic pressures. The implementation of fisheries management is, therefore, vital for their sustainable exploitation. This study aimed at investigating the catch distribution and size at 50% maturity (FL50%) of the Labeobarbus species. Samples were collected monthly from May 2016 to April 2017 at four sites. The relative abundance, catch per unit effort (CPUE), and size distribution of these species was computed, and logistic regression was used to calculate FL50%. Of the 15 species observed, five species constituted 88% of the total catch. The monthly catch of the Labeobarbus spp. declined by more than 85% since 1993 and by 76% since 2001. Moreover, the CPUE of Labeobarbus has markedly decreased from 63 kg/trip in 1991–1993 to 2 kg/trip in 2016–2017. Additionally, large size specimens (≥30 cm fork length) were rarely recorded, and FL50% of the dominant species decreased. This suggests that the unique species flock may be threatened by extinction. Given the size distribution of the species, the current social context, and the need for a continuous supply of fish for low-income communities, a mesh-size limitation represents a more sustainable and acceptable management measure than a closed season. This paper illustrates the tension between sustainable development goal (SDGs) 1—No Poverty, 2—Zero Hunger, and 8—Decent Work and Economic Growth in Bahir Dar City on the one hand, and SDG’s 11—Sustainable Cities and Communities, 12—Responsible Consumption and Production, and 14—Life Below Water on the other hand. A key for the local, sustainable development of the fisheries is to find a balance between the fishing activities and the carrying capacity of the Lake Tana. Overfishing and illegal fishing are some of the major threats in this respect.