Study on Prevalence of Larvae of Contracaecum Nematode in Tilapia Fish on Tributaries of Lake Tana

Assessment and Analysis of Morphometric Characteristics of Lake Tana Sub-basin, Upper Blue Nile Basin, Ethiopia

International Journal of River Basin Management ◽

10.1080/15715124.2021.1938091 ◽

2021 ◽

pp. 1-51

Author(s):

Bitew G. Tassew ◽

Mulugeta A. Belete ◽

K. Miegel

Keyword(s):

Morphometric Characteristics ◽

Nile Basin ◽

Lake Tana ◽

Blue Nile ◽

Blue Nile Basin ◽

Upper Blue Nile Basin

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Surface and subsurface flow effect on permanent gully formation and upland erosion near Lake Tana in the northern highlands of Ethiopia

Hydrology and Earth System Sciences ◽

10.5194/hess-14-2207-2010 ◽

2010 ◽

Vol 14 (11) ◽

pp. 2207-2217 ◽

Cited By ~ 94

Author(s):

T. Y. Tebebu ◽

A. Z. Abiy ◽

A. D. Zegeye ◽

H. E. Dahlke ◽

Z. M. Easton ◽

...

Keyword(s):

Water Table ◽

Gully Erosion ◽

Grazing Land ◽

Cross Sectional ◽

Lake Tana ◽

Erosion Rates ◽

Remotely Sensed Imagery ◽

Reservoir Siltation ◽

Upland Erosion ◽

Elevated Water

Abstract. Gully formation in the Ethiopian Highlands has been identified as a major source of sediment in water bodies, and results in sever land degradation. Loss of soil from gully erosion reduces agricultural productivity and grazing land availability, and is one of the major causes of reservoir siltation in the Nile Basin. This study was conducted in the 523 ha Debre-Mawi watershed south of Bahir Dar, Ethiopia, where gullies are actively forming in the landscape. Historic gully development in a section of the Debre-Mawi watershed was estimated with semi structured farmer interviews, remotely sensed imagery, and measurements of current gully volumes. Gully formation was assessed by instrumenting the gully and surrounding area to measure water table levels and soil physical properties. Gully formation began in the late 1980's following the removal of indigenous vegetation, leading to an increase in surface and subsurface runoff from the hillsides. A comparison of the gully area, estimated from a 0.58 m resolution QuickBird image, with the current gully area mapped with a GPS, indicated that the total eroded area of the gully increased from 0.65 ha in 2005 to 1.0 ha in 2007 and 1.43 ha in 2008. The gully erosion rate, calculated from cross-sectional transect measurements, between 2007 and 2008 was 530 t ha−1 yr−1 in the 17.4 ha area contributing to the gully, equivalent to over 4 cm soil loss over the contributing area. As a comparison, we also measured rill and interrill erosion rates in a nearby section of the watershed, gully erosion rates were approximately 20 times the measured rill and interrill rates. Depths to the water table measured with piezometers showed that in the actively eroding sections of the gully the water table was above the gully bottom and, in stable gully sections the water table was below the gully bottom during the rainy season. The elevated water table appears to facilitate the slumping of gully walls, which causes the gully to widen and to migrate up the hillside.

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Trematodes (Plathelminthes) of Clarias gariepinus (Pisces: Clariidae) in Lake Tana, Ethiopia

Inland Water Biology ◽

10.1134/s1995082917020171 ◽

2017 ◽

Vol 10 (2) ◽

pp. 219-227 ◽

Cited By ~ 2

Author(s):

A. E. Zhokhov ◽

D. A. Morozova ◽

M. N. Pugacheva

Keyword(s):

Clarias Gariepinus ◽

Lake Tana

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Late Pleistocene and Holocene drought events at Lake Tana, the source of the Blue Nile

Global and Planetary Change ◽

10.1016/j.gloplacha.2011.06.004 ◽

2011 ◽

Vol 78 (3-4) ◽

pp. 147-161 ◽

Cited By ~ 105

Author(s):

Michael H. Marshall ◽

Henry F. Lamb ◽

Dei Huws ◽

Sarah J. Davies ◽

Richard Bates ◽

...

Keyword(s):

Late Pleistocene ◽

Lake Tana ◽

Blue Nile

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The Impact of Sampling Season and Catching Site (Wild and Aquaculture) on Gut Microbiota Composition and Diversity of Nile Tilapia (Oreochromis niloticus)

Biology ◽

10.3390/biology10030180 ◽

2021 ◽

Vol 10 (3) ◽

pp. 180

Author(s):

Negash Kabtimer Bereded ◽

Getachew Beneberu Abebe ◽

Solomon Workneh Fanta ◽

Manuel Curto ◽

Herwig Waidbacher ◽

...

Keyword(s):

Gut Microbiota ◽

Nile Tilapia ◽

Alpha Diversity ◽

Environmental Parameters ◽

Illumina Miseq ◽

Microbial Composition ◽

Lake Tana ◽

Future Work ◽

The Impact ◽

Sampling Season

The gut microbiota of fishes is known to play an essential role in diverse aspects of host biology. The gut microbiota of fish is affected by various environmental parameters, including temperature changes, salinity and diet. Studies of effect of environment on gut microbiota enables to have a further understanding of what comprises a healthy microbiota under different environmental conditions. However, there is insufficient understanding regarding the effects of sampling season and catching site (wild and aquaculture) on the gut microbiota of Nile tilapia. This study characterised gut microbial composition and diversity from samples collected from Lake Tana and the Bahir Dar aquaculture facility centre using 16S rDNA Illumina MiSeq platform sequencing. Firmicutes and Fusobacteria were the most dominant phyla in the Lake Tana samples, while Proteobacteria was the most dominant in the aquaculture samples. The results of differential abundance testing clearly indicated significant differences for Firmicutes, Fusobacteria, Bacteroidetes and Cyanobacteria across sampling months. However, Proteobacteria, Chloroflexi, Fusobacteria and Cyanobacteria were significantly enriched in the comparison of samples from the Lake Tana and aquaculture centre. Significant differences were observed in microbial diversity across sampling months and between wild and captive Nile tilapia. The alpha diversity clearly showed that samples from the aquaculture centre (captive) had a higher diversity than the wild Nile tilapia samples from Lake Tana. The core gut microbiota of all samples of Nile tilapia used in our study comprised Firmicutes, Proteobacteria and Fusobacteria. This study clearly showed the impact of sampling season and catching site (wild and aquaculture) on the diversity and composition of bacterial communities associated with the gut of Nile tilapia. Overall, this is the first study on the effects of sampling season and catching site on the gut microbiota of Nile tilapia in Ethiopia. Future work is recommended to precisely explain the causes of these changes using large representative samples of Nile tilapia from different lakes and aquaculture farms.

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