Spatial and temporal limnological status of Erelu Reservoir, southwestern Nigeria

Abstract

Water quality monitoring is essential for determining the current condition and long-term trends of a reservoir for effective management. The spatio-temporal dynamics of the trophic lake is crucial in defining its water quality as well as biodiversity. Hence, the physico-chemical parameters and primary productivity of Lake Erelu were monitored for twenty-one months (July 2013-March 2015) to determine its suitability for sustainable fish production. The study area was temporally and spatially stratified. Temporal stratifications covered wet (April to October) and dry (November to March) seasons. Spatially, the lake was divided into lower (LZ), middle (MZ) and upper (UZ) zones based on geographical locations. Four sampling points were randomly selected in each zone. Water samples were collected monthly from each of the sampling points following standard methods and analyzed for variables such as biological oxygen demand (BOD), Nitrate (NO), Lead (Pb) and primary) and dry (1.41 ± 0.52 mgL) were significantly different. NPP did not differ significantly between seasons and between spaces. The physico-chemical parameters revealed seasonal and spatial variations which fall within desirable limits for fish production. Also, the lake was more productive during the dry season than rainy season.

Limnological variables as a determinant of fish parasites abundance in the Esa-Odo reservoir, Esa-Odo Southwestern Nigeria

“…The end product of the aerobic breakdown of organic nitrogenous substance are nitrates (Walakira & Okot-Okumu 2011). The concentration of nitrates in the Esa-Odo reservoir conforms to records from some investigated freshwater bodies in Nigeria such as the Erelu reservoir which recorded a mean nitrate value of 0.67 + 0.06 mg/L (Kareem et al 2018). Most of the water samples in each zone were within the permissible range of nitrate values as recommended by the (Nigerian Standard for Drinking Water Quality 2007).…”

Length-Weight Relationship and Condition Factor of Oreochromis niloticus (Linnaeus, 1758) in Selected Tropical Reservoirs of Ekiti State, Southwest Nigeria

“…Despite numerous studies on the length-weight association and condition factor for fish in Nigerian water bodies (Imam et al 2010;Ndimele et al 2010;Ayoade 2011;Ikongbeh et al 2012;Dan-Kishiya 2013;Fagbuaro 2015;Kareem et al 2015;Fagbuaro et al 2016;Kareem et al 2016;Moslen and Miebaka 2017;Omotayo et al 2018;Laurat et al 2019;Oladimeji et al 2020;Olatunde 2020;Mohammud et al 2020), but the reports on lengthweight relationship and condition factor of O. niloticus from Ekiti State reservoirs are scarce. This study compares the length-weight relationship and differences in the condition factor of O. niloticus from Egbe, Ero and Ureje reservoirs in Ekiti State, southwest Nigeria, to improve sustainable fishing management.…”