Motives for Labeobarbus Fish Species Migration to Gumara River, Lake Tana, Ethiopia

Abstract

The flocks of endemic fish species in Lake Tana, i.e., Labeobarbus species (L. intermiduis, L. tsanansis, L. brevicifaleus, L. acutirostris and others) migrate for spawning during the rainy season (peak from August to September) to the rivers that flow into Lake Tana. These migrations make them vulnerable for aggregated fishery. The Gumara River is one of the tributaries that flow into Lake Tana where the Labeobarbus fish species migration is predominant. A study was conducted to determine the factors that trigger Labeobarbus migration to Gumara River from January 2001 to November 2001. The objectives of the study were: to determine the factors that stimulate the migration of the Labeobarbus fish species to the Gumara River mouth and upstream and based on that to recommend protective measures. Fish and environmental data were collected at two sites, i.e., at the River mouth and upstream of Gumara. Data were analyzed using simple statistical models. Amount of rainfall and level of the lake appeared to trigger upstream migration of Labeobarbus. To protect the breeding population of migrating Labeobarbus, fishing must be prohibited from July-October at the river mouths, rivers and their tributaries.

Keywords: Labeobarbus species; fish migration; spawning population; environmental factors, management