Effects of water physico-chemical parameters on tilapia (Oreochromis niloticus) growth in earthen ponds in Teso North Sub-County, Busia County

Abstract

Small-scale fish farmers in developing countries are faced with challenges owing to their limited information on aquaculture management. Nile tilapia farmers in Teso North Sub-County recorded lower yields than expected in 2009 despite having been provided with required inputs. Water quality was suspected to be the key factor responsible for the low yields. This study sought to assess the effects of earthen pond water physico-chemical parameters on the growth of Nile tilapia in six earthen fish ponds under semi-intensive culture system in Teso North Sub-County. The study was longitudinal in nature with pond water and fish being the units of analysis. Systematic sampling was used to select five ponds while a control pond was purposively selected based on its previously high harvest. Four ponds were fed by surface flow and two by underground water. Each pond was fertilized and stocked with 900 fry of averagely 1.4 g and 4.4 cm. Physico-chemical parameters were measured in-situ using a multi-parameter probe. Sixty fish samples were randomly obtained from each pond fortnightly for four months using a 10 mm mesh size and measured, weighed and returned into the pond. Mean range of physico-chemical parameters were: dissolved oxygen (DO) 4.86-10.53 mg/l, temperature 24-26°C, pH 6.1-8.3, conductivity 35-87 μS/cm and ammonia 0.01-0. 3 mg/l. Temperature (p = 0.012) and conductivity (p = 0.0001) levels varied significantly between ponds. Overall Specific Growth Rate ranged between 1.8% (0.1692 g/day) and 3.8% (1.9 g/day). Ammonia, DO and pH in the ponds were within the optimal levels for growth of tilapia, while temperature and conductivity were below optimal levels. As temperature and DO increased, growth rate of tilapia increased. However, increase in conductivity, pH and ammonia decreased fish growth rate. Temperature and DO ranging between 27 and 30°C and 5-23 mg/l, respectively, and SGR of 3.8%/day and above are recommended for higher productivity.

Effect of Garcinia kola seeds supplemented diet on growth performance and gonadal development of Oreochromis niloticus juveniles breed in ponds

“…The average values of water quality parameters such as temperature, transparency, pH, dissolved oxygen, nitrite, nitrate, and ammonia monitored throughout the trials were considered as suitable for the survival, normal growth, as well as good general physiology of O. niloticus. These values were in accordance with the findings of Yoo and Lee, 2016, Makori et al 2017and Nyadjeu et al (2018 and could partially justify the absence of mortality observed throughout the study, coupled with experimental fish's apparent good health observed through the results on both the growth and feed utilization.…”

Aquaculture as Source of Environmental Contaminants: A Study of Earthen Pond versus Plastic Pond

“…Results presented in Table 1 reveals that the pH of water from both ponds are in the alkaline range, although that of the earthen pond is more alkaline (8.6) than that of the plastic pond (7.5). While this pH range is consistent with the quality of water tolerable to many fish species (Makori et al, 2017;Deekae et al, 2010), the value obtained for the earthen pond is slightly above the upper limit of 6.5 -8.5 specified by the world health organization (WHO, 2011). The pH values are in agreement with the alkalinity of the pond waters, a measure of the ability to neutralize strong acids, usually expressed as mg/L CaCO3.…”

Assessing the potential effects of nevirapine in South African surface water on fish growth: A chronic exposure of Oreochromis mossambicus

“…In addition, the length and mass measurements recorded in this study as well as the growth rate are comparable to those from a previous study on O. mossambicus from a natural environment in which 1-day-old larvae had a mean standard length of 4 mm 39 and O. niloticus Table 1: Mean total length, mass and condition factor of control fish exposed to borehole water (Control) or the solvent dimethysulfoxide (DMSO) and of nevirapine-exposed fish The strong positive correlation between length and mass measurements, and between fish age and both length and mass measurements, in all groups, confirmed that as the larval and juvenile stages of O. mossambicus were aging, they were also increasing both in length and in mass, as is the case for healthy fish. 28,40 If NVP in water had a negative impact on fish growth, the relationship between length and mass would have been affected, and the correlation would not have been strong and positive. In fisheries, healthy fish are characterised by strong positive mass-length, age-length and age-mass relationships; and length measurements are the most used in regressive models to predict either fish age or fish mass.…”

“…The fish in all three groups had a high and rapid mean SGR from Day 1 to Day 30; from Day 30 to Day 60, the mean SGR decreased in all groups but was still high compared to the SGR recorded for O. niloticus in their natural environment. 40 O. mossambicus early life stages are known to have a fast and high initial growth rate to allow them to reach large sizes quickly in order to avoid predation. 41 According to Sparre and Venema 29 , in normal conditions, the growth rate of a healthy fish decreases as the fish gets older, becoming zero when the fish gets to its maximal growth.…”

“…The variations observed in growth rate of the fish in the same group have also been observed in previous studies on Oreochromis and are believed to be mainly caused by fish density, food quality and variation in temperature of the water. 33,34,40,41 As this study was conducted in a controlled-environment room, and the fish in all groups were fed at the same time and with the same amount of food, the only factor that could have caused the variations in growth rate would be the slight variations in fish density, as explained above.…”