Abstract
Agriculture around Nike lake uses fertilizers. Fertilizers are known to cause eutrophication of water bodies and associated algal blooms whose consequences may be deleterious to the environment and man. We investigated ex situ to assess the effect of the nutrients on the algal flora and show the impact of farm land runoffs on aquatic environment. The lake water was analysed for initial nitrogen, phosphorus and potassium; and algal content using standard methods. The fertilizer sources used by the farmers—NPK (20:10:10 and 15:15:15); urea and poultry drops, were used in the study to enrich the lake water in concentrations of 0.2, 0.4, 0.6, 1.0 and 2.0 g/L in three replicates respectively. A control was set up without the fertilizer sources and the set up was left on a laboratory bench and monitored for 36 days. Cyanobacteria (blue green algae), Chlorophyta (green algae) and Bacillariophyta (diatoms) were encountered and their population increased with time and increase in concentration of fertilizers. The following taxa were encountered—Gloeocapsa, Anabaena, Oscillatoria (blue-green algae); Chlorella, Chlamydomonas, Spirogyra, Closterium, Pediastrum, Ankistrodesmus, Selenastrum, Scenedesmus, Staurastrum (green algae); Pinnularia and Navicula (diatoms) some of which are notable bloom forming species.
Highlights
Nike lake, Enugu, is located between 6 ̊30'19.5"N 6 ̊30'22.6"N and 7 ̊30'47.2"N - 7 ̊30'50.9"N at an elevation of about 172.5 meters above sea level
The fertilizer sources used by the farmers—NPK (20:10:10 and 15:15:15); urea and poultry drops, were used in the study to enrich the lake water in concentrations of 0.2, 0.4, 0.6, 1.0 and 2.0 g/L in three replicates respectively
Thirty one taxa of algae belonging 4 classes were observed in the Nike lake water used for the experiment
Summary
Enugu, is located between 6 ̊30'19.5"N 6 ̊30'22.6"N and 7 ̊30'47.2"N - 7 ̊30'50.9"N at an elevation of about 172.5 meters above sea level. Cultural eutrophication is a process where a water body changes due to increased reception of nutrients such as nitrogen, potassium and phosphate from anthropogenic activities [1] and silicon, potassium, calcium, iron and manganese [3] These nutrients from the catchment area (allochthonous sources) bring pressure on the receiving environment causing major changes in the ecosystem thereby jeopardizing many beneficiaries of the resources. The algal biodiversity of the water as reported in Nweze and Domrufus [2] showed that the metaphyton algal flora was composed of 34 taxa of algae belonging to 5 classes Some of these, such as Microcystis, Anabaena, Oscillatoria and Euglena are known bloom forming species. This ex situ investigation was carried out to assess the effect of nutrients contained in inorganic fertilizers and poultry manure on resident algal biodiversity of Nike lake to give insight into their effects on aquatic environment when taken in through runoffs from farm lands
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
