Thesis Abstract

Abstract
The biophysical properties of wastewater from fish ponds are crucial for understanding the environmental impact of aquaculture activities. This study aimed to investigate the biophysical properties of wastewater from fish ponds, focusing on parameters such as temperature, pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), and total suspended solids (TSS). The research was conducted on several fish ponds in a rural area, where water samples were collected at different depths and locations within the ponds. The results showed that the temperature of the wastewater varied depending on the time of day and depth within the ponds, with higher temperatures observed during the day and near the surface. The pH of the water samples ranged from slightly acidic to slightly alkaline, indicating a relatively neutral environment overall. Dissolved oxygen levels were found to fluctuate throughout the day, with higher concentrations observed during daylight hours due to photosynthetic activity by aquatic plants. The BOD levels in the wastewater samples were found to be elevated, indicating a high level of organic matter present in the water. This could be attributed to the accumulation of fish waste, uneaten feed, and other organic debris in the ponds. The TSS concentrations were also relatively high, suggesting a significant amount of particulate matter suspended in the water. Overall, the biophysical properties of wastewater from fish ponds can have significant implications for water quality and ecosystem health. High BOD and TSS levels can lead to oxygen depletion, nutrient enrichment, and habitat degradation in aquatic environments. Therefore, proper management practices, such as regular water exchange, nutrient monitoring, and waste removal, are essential to mitigate the environmental impact of aquaculture activities. Understanding the biophysical properties of wastewater from fish ponds is crucial for sustainable aquaculture practices and environmental conservation. Further research is needed to explore the long-term effects of aquaculture activities on water quality and ecosystem dynamics, as well as to develop effective strategies for wastewater treatment and management in fish farming operations.

Thesis Overview

Agriculture in the early days was generally considered too small an industry to have significant impact on the environment. The remarkable growth of the agriculture industry in many countries over the past decades has increased adverse impact on the environment. (Acketors, 2014). The cultivation of organisms in ponds (Tincker, 2012), tanks (Millamena et al., 1991), rivers and coastal areas may have great influence on the environment, in addition to the impacts of all human activities. According to Hopkins et al., (1995), there are potential and identified environmental impacts of fish farming such as the following. Wetlands, such as mangroves and mud flats, destruction for construction of ponds. Hyper-nitrification of estuarine ecosystems by fishpond effluent. “Biological pollution” of native fish stocks through escarpment of agriculture stocks.  The last for impacts can be addressed through improved water management methods. The environmental  impact of fish culture have been well documented as a result of the explosive growth of such operation in south east Asia and to a lesser extent in Latin America (Aiken, 2015) and it has also caused social impacts (Bailey, 2001). Chamberlin (2015) discovered, from fishpond effluent management study that dissolved oxygen, pH, ammonia, and nitrite, hydrogen sulfide, redox potential, sediments, phytoplankton, and bacterial counts are fishpond parameters to be monitored. Depending on the stocking density, the concentration of materials, suspended solid and oxygen demanding subsistence may be varied. During the harvest time, the water in ponds is drained and the nutrients, suspended solids and BOD are the highest in discharged water. Solid matter, mainly mixture of uneaten feed, feces, phytoplankton colonizing bacteria and dissolved matter such as ammonia, urea carbon dioxides and phosphorus are the major constituents of the effluents of fish farms (Macintosh, and Philips, 1992)”. A very high nutrient load can be expected in effluents during harvesting, draining and cleaning of ponds, because additional discharge of material previously bound to sediment and particulate in matter. These issues when not monitored and checked could precipitate worrisome environmental problems. It is therefore necessary to embrace on this study.