Impact of Urban Effluents on the Macroinvertebrates of a Creek in Accra, Ghana

The impact of effluents on the macroinvertebrate communities of an urban creek in Accra was studied. Five study stations were selected along the reaches of the creek. Water and benthic samples were collected and analyzed between September 2005 and February 2006. The study showed that the effluent discharges caused a significant increase in BOD, COD and NH3 at the stations that received the effluents. The high levels of total and faecal coliforms at the midstream sections of the creek (626.0 x 104 cfu/100 ml and 75.30 x 104 cfu/100 ml, respectively) indicated increased pollution levels compared to the reference stations (446.0 x 103 cfu/100 ml and 133.0 x 103 cfu/100 ml). The Nima Creek showed characteristics of a disturbed urban creek. A total of 19 macroinvertebrate taxa, comprising a total of 11,613 individuals, were collected. Estimated Shannon-Weiner Diversity Index (H´) was low at the midstream section of the creek, H’= 1.14, where the effluents were concentrated than at the upstream H’=1.44 or downstream H’= 1.38 sections of the creek. Chironomini and Physa were the most abundant taxa within the creek, dominated by the genus Chironomus, which is known to be tolerant to pollution, which confirmed the polluted state of the creek. Rigorous and regular assessment and monitoring of effluents from waste treatment plants and other sources that discharge into the creek, with the aim of complying with the Environmental Protection Agency (EPA) guidelines are some of the mitigative measures suggested to protect life in the creek

Changing Agricultural Practices and Indigenous Food Crops in the Upper Afram Basin of Ghana

The Forest Savanna Transition zone within which the Upper Afram basin lies, account for a wide variety of food crops and plant species. This study examined the effects of changing ag­ricultural practices on cultivation and availability of indigenous food crops within the basin. Qualitative data obtained from 240 farmers through individual interviews and Focus group dis­cussions were analyzed thematically. The study revealed that even though the farmers employed the traditional mixed cropping system, the widespread use of agro-chemicals in the study area was limiting the practice of intercropping. This accounts for the current dominance of mono cropping system in the study area. These changes have affected the cultivation of a wide variety of indigenous foods within the basin. The uncontrolled use of agro-chemicals constituted one of the major agronomic constraints affecting the cultivation of these crops. Adequate technical support services to effectively control agrochemical abuse among the local farmers will, there­fore, be required. Increased sensitization on the need for local farmers to refocus and maintain some of the traditional agricultural practices that ensured the cultivation of a wide variety of indigenous food crop varieties (NUCS) in their farms is also suggested