Dereje Tewabe*, Birhan Mohamed, Mihret Endalew and Binyam Hailu
Bahirdar fisheries and other aquatic life research center, Ethiopia
Received: 01 February, 2016; Accepted: 22 March, 2016; Published: 24 March, 2016
Dereje Tewabe, Bahirdar fisheries and other aquatic life research center, PO Box 794, E-mail:
Tewabe D, Mohamed B, Endalew M,Hailu B (2016) Composition, Distribution, Fishing Activities, and Physico-Chemical Characteristics: The Case of Jemma and Wonchit Rivers, Amhara Region, Ethiopia. Glob J Allergy 2(1): 010-014. DOI: 10.17352/2455-8141.000013
© 2016 Tewabe D, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Millettia ferruginea; Pooled water; Spawning aggregation; Species composition
The distribution of fish species in Jemma and Wonchit Rivers was studied from November 2012 to May 2014 based on samples collected during wet and dry seasons using gillnets of 60, 80, 100, 120 and 140 mm stretched mesh sizes. Labeobarbus intermedius, Labeobarbus nedgia, Heterobranchus longifilis, Bagrus docmak, Varicorhinus beso and Oreochromis niloticus are commercially important fish species found in both rivers of the pooled experimental fish catch. But, Synodontis schall, Ramias loti, Labeo forskhalii, Tilapia rendelii, Mormyrus kannume and Bagrus bajad are found in river Jemma only. The high level of pH in Wonchit (9.14) may be lethal for some of the fishes that found in the river. The pH in Jema (8.79) might indicate higher productivity of water, but it is very approximate to the higher limit. The most likely explanations for the fishing activity of fish species are the increase of the illegal commercial plant poisoning material used for fishing activities that seriously affects the riverine fishery of the surroundings. Fishery targeting their aggregations in the pooled, and the increasing trend of the degradation of spawning and nursery habitats by poisoning plant in the water pooled area should be protected. This means, there should be a need for urgent development of a management plan focusing on ensuring sustainable utilization of a resource. Control the production grounds of Millettia ferruginea poisoning plant from its source and its market is important.
Shibru Tedla , has listed and described about 94 species of fishes in Ethiopia. Although extensive review work is in progress, it appears that there are about 183 valid indigenous species included in 25 families so far known from Ethiopian fresh waters . At the moment, we have no clear and complete list and description of the diversity of the fish fauna of Ethiopia.
Many of the drainage basins, especially the rivers, are not exhaustively explored . According to Abebe Getahun , there are about 38 species and two sub-species endemic to Ethiopia. Lake Tana from Abay drainage basin exclusively has larger number of endemic species (twenty one species) in the country . According to Golubtsov and Mina , the total numbers of valid fish species known from Ethiopian inland water bodies is about 168 to 183 including 37-57 countrywide endemics. There are also about 10 exotic fish species introduced from abroad into Ethiopian freshwaters . The Rift valley is the region with highest number of introduced fish species. Eventhough there are about 25 fish families reported in Ethiopia [3,4]. Currently, results of a study indicate that the number of species could increase to 200 and above .
The freshwater fish fauna of Ethiopia contains a mixture of Nilo-Sudanic, East African and endemic forms (Boulenger, 1975; Banaerscu, 1975; Nichols and Griscom, 1975 and Roberts, 1975 as cited in Abebe Getahun and Stiassny, 1998). The Nilo-Sudanic forms are related to West African fishes and this is believed to be past connections of the Nile to central and West African river systems [2,7,8,]. The Nilo-Sudanic forms are the dominant forms in terms of diversity and represented by a large number of species found in the Baro-Akobo, Omo-Gibe, Tekeze and Abay drainage basin (e.g., the genera Alestes, Bagrus, Citharinus, Hydrocynus, Hyperopisus, Labeo, Mormyrus, etc…) . These forms dominate the Nile basin fishes . de Graff , has described some of the elements of the Nilo-Sudanic species from southern Rift valley lakes. These include the families Mormyridae, Cyprinidae, Bagridae, Clariidae and Mockokidae.
Wonchit and Jemma Rivers are some of the rivers flowing to lower course of Abay, in which adequate attention has not been given in the study of the diversity, abundance, fishing activity and socio-economic conditions of fish fauna due to inaccessibility for transportation, security and harsh geographical features. The purpose of this study was, therefore, to answer the following leading research questions:
Do Wonchit and Jemma Rivers fishes vary in species composition?
What do fishing activities look like and what type of fishing gears used?
What is the current water quality status of the two rivers look like?
The major objective of the study was to generate baseline scientific information/ data about economically important and commonly found fish species for management and sustainable utilization of the resources
• To generate baseline information for fishing and marketing activities of the study areas.
• To identify species composition of fishes in the rivers.
• To characterize physico-chemical parameters of the rivers.
Materials and Methods
Data was collected from November, 2012 to June, 2014 considering wet and dry seasons of a year that means four time sampling have been done during the study period. Wonchit and Jema Rivers are mainly found in North Shewa zone of Midaworemo and Merhabetie Woredas, respectively and they are in drainage basin of Abay River. Major beneficiaries of the fisheries resource are Midaworemo, Merhabetie, Muteranajiru, Ensaro and neighboring Woredas of south Wollo of the same region and Woredas from Oromia region are main ones.
Stratified sampling sites were selected based on its topography, encroachment and fishing activities. Samples were collected using gillnets of various mesh sizes (6 cm, 8 cm, 10 cm, 12 cm and 14 cm stretched mesh) and monofilament nets with various stretched mesh sizes (5 mm-55 mm stretched mesh). Specimens were brought to the lab for species identification purpose. Purposive sampling techniques were used to address fishers. Personal observation was also made during the market day.
Results and Discussion
Fishing and marketing of fish in wonchit and jema rivers
The catches of fishers used for both home consumption and generate income by selling at the nearby local markets. Hence, Meragna town from Midaworemo and Alemketema from Merhabetie are towns where fish market was commonly practiced during the market day. The most popular fishing gear used for fishing were Millettia ferruginea and Balanites aegyptiaca in Amharic called Bedeno, Jemo or Kudkuda (locally available plant poisoning material). The plant materials used for fishing are seeds of Millettia ferruginea and barks of Bedeno by crashing and diluting with water, squeeze and then, spread over the surface of the pooled water bodies starting from post rainy seasons up to just pre-rainy seasons of a year. The effects of two different plant poisoning materials used for fishing are quite different; Maletia fergunia damages the eye of the fish (ref.). As a result the poisoned fish is unable to see the environment it lives, so it becomes too susceptible for fishers trap (ref.). But when we see the fish killed with Bedeno its body cavity had bad smell and changed its normal color to black color.
Catches of the fishers brought to the market into two different forms:
Whole fish gutted and sun dried 2) whole fresh fish gutted and washed.
During fish market survey 1.2 m Heterobranchus longifilis gutted fresh whole fish was registered which was caught by plant poisoning materials. Many other medium sized with the range of 70 cm and 80 cm whole fresh gutted washed Clarias gariepinus and Heterobranchus longifilis were recorded. Large Labeobarbus fish species appeal at the market in sun dried forms filled in sacks. During market transaction period, most of the time customers were rural women. Catches of fishers brought to market by both men and women. Age structures were not clearly observed, youths, middle classes and old aged groups were equally involved in the market to sell their product. Millettia ferruginea seed was sold to the fishers in the local market from where it grows at relatively higher altitude areas of the vicinity. Fishing activities with plant poisoning materials had been mainly carried out by youth and middle class male society groups. These fishing activities were intensively carried out during the dry seasons starting from February up to the end of fasting seasons where no farming activity is taking place. These seasons are very conducive for fishing, because the volume is low and make intermittent pools which would be important for plant poisoning materials to be concentrated and not washed out by running waters. Mass flee of fishers about 30 individuals in one group to downstream by carrying plant poisoning materials, locally made netlike sack material to collect poisoned fish from the surface of the water and Gejera to kill the weakened poisoned fish and sacks to hold their catches was common (Figure 1).