A Review on the Causes for the Loss of Major Fishes and Prospects for Future Research in Ethiopia

Abstract

This paper is aimed in reviewing major causes and losses on fish population in Ethiopia and set a future scenario. Rapid declines threaten the persistence of many marine fish population now days. Reductions in fishing pressure, although clearly necessary for population recovery, are often insufficient. Persistence and recovery are also influenced by life history, habitat alteration, changes to species assemblages, genetic responses to exploitation, and reductions in population growth attributable to the Alley effect. Heightened extinction risks were highlighted recently listed as endangered, on the basis of declines as high as 99.9% over 30 years. Failure to prevent population collapses, and to take the conservation biology of marine fishes seriously, will ensure that many severely depleted species remain ecological and numerical shadows in the ecosystems that they once dominated. Currently, however, about 25% of world fish stocks are overexploited or fully depleted and overcapacity in fishing fleets is the norm rather than the exception. Indeed, many experts agree that the exploitation limit of marine resources has been reached, if not exceeded, and that this overcapacity of fleets, excessive fishing quotas, illegal fishing practices and the generally poor management of most fisheries are to blame, Habitat destruction, pollution, climate change and invasive species also have an impact upon fish populations. Also, a changing environment affects stock abundance, and some stocks experience collapse from environmental causes alone. In many instances, it is quite difficult to determine the main causes of the depletion of fish stocks. Although the review concentrate in Ethiopia on overfishing of fisheries depletion and collapse, the depletion of global fish stocks cannot be attributed to fishing alone. Many scientists have done research, recommended and directed to focus on the prevention of fish losses and the sector scientists and government to discuss on the issue and set a sustainable fish management policies and Laws on future concerns.

Keywords: biodiversity loss, Conservation, fish loss, population ecology.