International Journal of Fisheries and Aquatic Studies
2019, Vol. 7, Issue 6, Part C
Ecotroph: A simple model to assess fishing and trophic interactions in Lake Victoria
Author(s): Daniel Mungai Ndegwa, Chrispine Sangara Nyamweya and Enock Obuba
Abstract: Ecotroph is a simple model that structure ecosystems as systems of energy flow surging from low to high trophic levels. Lake Victoria is the second-largest freshwater lake in the world. It is a producer of 1% of global capture fisheries and 8% producer of global inland fishery. The lake has faced overfishing and overexploitation. A pre-existing Ecopath with Ecosim model of Lake Victoria 2016, was used for data extraction, simulations, and analysis. Model outputs were juxtaposed against current biological data to determine the validity of the trends using Pearson’s correlation and modelling efficiency. Fishing did not appear to have tremendous effect on the trophic interactions. Fishing at lower trophic levels negatively impacted the ecosystem than when fishing was directed to high trophic level species. The system showed resilience and stability when fishing was directed towards top predators. Lake Victoria exhibited top-down characteristics which are usually resistant to fishing.
Related Graphics: Click here for more related graphics:
Fig. 1: Fishing loss rate and the fishing mortality, the two important indices that describe the effects of fisheries on the ecosystem
Fig. 2: Biomass across trophic levels removed through fishing by different fleets which are long lines, gill nets, small seines and other fishing fleets in Lake Victoria.
Fig. 3: The distribution of species biomass across the trophic levels
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How to cite this article:
Daniel Mungai Ndegwa, Chrispine Sangara Nyamweya, Enock Obuba. Ecotroph: A simple model to assess fishing and trophic interactions in Lake Victoria. Int J Fish Aquat Stud 2019;7(6):210-215.
