Longitudinal river zonation in the tropics: examples of fish and caddisflies from endorheic Awash river, Ethiopia

Primary Research PaperSpecific concepts of fluvial ecology are well studied in riverine ecosystems of the temperate zone but poorly investigated in the Afrotropical region. Hence, we examined the longitudinal zonation of fish and adult caddisfly (Trichoptera) assemblages in the endorheic Awash River (1,250 km in length), Ethiopia. We expected that species assemblages are structured along environmental gradients, reflecting the pattern of large-scale freshwater ecoregions. We applied multivariate statistical methods to test for differences in spatial species assemblage structure and identified characteristic taxa of the observed biocoenoses by indicator species analyses. Fish and caddisfly assemblages were clustered into highland and lowland communities, following the freshwater ecoregions, but separated by an ecotone with highest biodiversity. Moreover, the caddisfly results suggest separating the heterogeneous highlands into a forested and a deforested zone. Surprisingly, the Awash drainage is rather species-poor: only 11 fish (1 endemic, 2 introduced) and 28 caddisfly species (8 new records for Ethiopia) were recorded from the mainstem and its major tributaries. Nevertheless, specialized species characterize the highland forests, whereas the lowlands primarily host geographically widely distributed species. This study showed that a combined approach of fish and caddisflies is a suitable method for assessing regional characteristics of fluvial ecosystems in the tropicsinfo:eu-repo/semantics/publishedVersio

Study of agricultural impacts through fish base variables in different rivers

Dominant agricultural society of Nepal demonstrates the sign of compromises on its rural and virgin landscape. The current study investigates the fish base indices on some of its watershed. It is a proven fact that fish base variables such as species diversity and the abundance indicate the extent of impact by various disturbances on the ecological integrity of the river system. Three rivers, namely Jhikhukhola, Rapti and Tinau were studied to see the agricultural impact by taking fish species number and their abundance as the indicators in this work. The study was done for an academic purpose from 2003 to 2006 in which sampling was done using electro-fishing gear by standard wading method. Four replicates of sample taken in four major seasons were obtained in the field. Altogether, 10542 fishes of 24 genera and 34 species were captured during the entire sampling. The comparison of their distribution and abundance showed a clear sign of impact mainly on the downstream of the rivers indicating the rapid increase in unaccounted and indiscriminate use of agricultural inputs such as synthetic fertilizers and pesticides. This was further verified by nonparametric Kruskal-Wallis test which showed the significant variations in the impact on the downstream in major agricultural season

Length-weight relationship of sucker head, Garra Gotyla Gotyla (Gray, 1830) in different rivers of Nepal and the influence of monsoon

Size structure data particularly that of length and weight is very important fisheries management tool, which is also applied to assess the health, habitat and integrity of the rivers. Nepal is tremendously rich in both fisheries and water resource and thus, this analysis is very important. However, this kind of analysis is not common in fisheries studies and hence the size structure information of all the fish in Nepal is wanting. This study simply tries to open the door for such studies with the study of the sucker head Garra gotyla gotyla, a very common fish in Nepal. The field observation was done in nine rivers of the country in all the seasons of the 2003 by using electrofishing gear. The length-weight relationship was found to vary both spatially and temporally among rivers and seasons respectively indicating different conditions in different rivers. The length weight relationship also showed some interesting facts about the seasonal cycle of the species indicating the period of growth and stress in different rivers. The monsoon event was found to be highly influential in this relationship

\u201cIntegrating BOMOSA cage fish farming system in reservoirs, ponds and temporary water bodies in Eastern Africa\u201d

Project summary Project full title: Integrating BOMOSA cage fish farming systems in reservoirs, ponds and temporary water bodies in Eastern Africa Project acronym: BOMOSA Keywords: aquatic farming, participatory approach, socio-economic models Project abstract: The BOMOSA Project will research the economic viability, social acceptance and necessary institutional environment of a relatively simple technology that has been proven technically feasible over the last two years. BOMOSA is pioneering small scale fish farming in Eastern Africa by establishing rural aquaculture networks (coordinated in a \u201chub and plot\u201d system) to economically integrate aquaculture with agriculture. The BOMOSA system will form the basis of a socio-economic model that will contribute to poverty alleviation in Eastern Africa by providing sources of supplementary high protein food and additional income to rural communities in Kenya, Ethiopia and Uganda. The 36-month project involves four European partners: \u2022 two universities, a science academy and an NGO and \u2022 six African partners: two Kenyan universities and four government\u2013run fisheries research centers from Kenya (2) and one each from Ethiopia and Uganda. The summarized scientific and technical objectives of the project are: \u2022 Apply a participatory approach to define targets in terms of economic viability and social acceptability at community levels for the new BOMOSA plots. \u2022 Develop and validate an evaluation method using remote sensing to assess and characterize water bodies for use as potential BOMOSA plots. \u2022 Set up fourteen BOMOSA plots and optimize the technology in three types of small (less than 5 ha.) water bodies within four eco-zones across Kenya, Ethiopia and Uganda. \u2022 Evaluate locally available, agricultural by-products and cost-effective processing technologies as a resource for sustainable production of low-protein fish feed. \u2022 Determine requirements and make recommendations for a legal and regulatory framework based on potential veterinary, public health and environmental impacts of BOMOSA. \u2022 Develop capacity building and dissemination material for the local community, relevant authorities and policy makers and the international scientific community. \u2022 Develop a socio-economic model for sustainable introduction and widespread uptake of the BOMOSA scheme in Eastern Africa

\u201cIntegrating BOMOSA cage fish farming system in reservoirs, ponds and temporary water bodies in Eastern Africa\u201d

Project summary Project full title: Integrating BOMOSA cage fish farming systems in reservoirs, ponds and temporary water bodies in Eastern Africa Project acronym: BOMOSA Keywords: aquatic farming, participatory approach, socio-economic models Project abstract: The BOMOSA Project will research the economic viability, social acceptance and necessary institutional environment of a relatively simple technology that has been proven technically feasible over the last two years. BOMOSA is pioneering small scale fish farming in Eastern Africa by establishing rural aquaculture networks (coordinated in a \u201chub and plot\u201d system) to economically integrate aquaculture with agriculture. The BOMOSA system will form the basis of a socio-economic model that will contribute to poverty alleviation in Eastern Africa by providing sources of supplementary high protein food and additional income to rural communities in Kenya, Ethiopia and Uganda. The 36-month project (october 2006-september 2009) involves four European partners: \u2022 two universities, a science academy and an NGO and \u2022 six African partners: two Kenyan universities and four government\u2013run fisheries research centers from Kenya (2) and one each from Ethiopia and Uganda. The summarized scientific and technical objectives of the project are: \u2022 Apply a participatory approach to define targets in terms of economic viability and social acceptability at community levels for the new BOMOSA plots. \u2022 Develop and validate an evaluation method using remote sensing to assess and characterize water bodies for use as potential BOMOSA plots. \u2022 Set up fourteen BOMOSA plots and optimize the technology in three types of small (less than 5 ha.) water bodies within four eco-zones across Kenya, Ethiopia and Uganda. \u2022 Evaluate locally available, agricultural by-products and cost-effective processing technologies as a resource for sustainable production of low-protein fish feed. \u2022 Determine requirements and make recommendations for a legal and regulatory framework based on potential veterinary, public health and environmental impacts of BOMOSA. \u2022 Develop capacity building and dissemination material for the local community, relevant authorities and policy makers and the international scientific community. \u2022 Develop a socio-economic model for sustainable introduction and widespread uptake of the BOMOSA scheme in Eastern Africa