ABSTRACT

The study was conducted to explore the physicochemical parameters and anionic properties of surface water from the Moheshkhali fishing zone at Cox’s Bazar coastal area of Bangladesh starting from December 2017 to November 2018. The surface water samples were collected from three sampling stations in the Moheshkhali fishing zones covering the seasons of pre-monsoon, monsoon and post-monsoon. The selected physicochemical parameters and anions were analyzed in the laboratory of the Department of Public Health Engineering (DPHE), Mohakhali, Dhaka, Bangladesh. The result of the study showed that temperature, turbidity, pH, TDS, TSS, salinity, DO, BOD, COD, NH3, NO3 – and PO4 3- were ranged from 27.5 to 29ºC, 720 to 890 NTU, 7.1 to 8.5, 311 to 615 mg/L, 17 to 38 mg/L, 10 to 29‰, 6.2 to 6.9 mg/L, 3.25 to 5.5 mg/L, 7.8 to 9.01 mg/L, 1.07 to 2.4 mg/L, 0.48 to 0.75 mg/L and 0.89 to 0.95 mg/L, respectively. Except turbidity, COD and NH3, all others physicochemical and anions of Moheshkhali fishing zones were within the acceptable range of standard limits. The study concluded that the studied marine surface water quality is suitable, which is safe and favorable for production of fishes and other aquatic organisms. But to maintain such type of favorable states, the study suggested for regular water quality monitoring coastal and also all existing rivers/fishing zones in Bangladesh.

Key words: Water quality, anionic properties, seasonal variation, marine environment.

Introduction

Marine water quality has become a matter of great concern because of its effects on human health and aquatic ecosystems including marine life (Gupta et al., 2009). Bangladesh’s coastal and marine environment is endowed with a warm tropical climate and high rainfall, rich in nutrients from the land and forming one of the most productive ecosystems in the world (Hossain, 2001; Islam, 2003). The Bay of
Bengal is rich in coastal and marine ecosystems and is home to a wide range of biodiversity including fish, shrimp, mollusks, crabs, mammals and seaweed. There are about 511 marine species along with shrimp in the waters of Bangladesh (Murshed-E-Jahan et al, 2014). The wellbeing of human largely depend on water and needs of water for every purposes ranging from domestic to industrial could not be ignored (Hiremath et al., 2011). All living things mainly aquatic organisms especially fisheries species depend on water for its existence (Hiremath et al., 2011). Water is the natural habitat of fishes and other aquatic animals, therefore of great importance to investigate water quality while studying fish production (Biggs et al., 2005). Water is the physical support for performing life functions such as feeding, swimming, breeding, digestion and excretion (Bronmark and Hansson, 2005). Actually, water quality is pointed as an important factor to the success or failure of a fish culture operation (Piper et al., 1982). The physicochemical characteristics are indeed vital water quality parameters for monitoring due to their instability (Efe et al., 2005; Pejman et al., 2009), where significant variations in physicochemical parameters affect the quality of water resources. It is the matter of worried that the main concern in the territorial waters is the condition of polluted waters, reducing the quality of the aquatic environment (Hamuna et al., 2018). The organic and inorganic
pollutants in the marine water can lead to the quality of water such as the biological function degradation and make an impact to the water (Tanjung et al., 2019). Organic and inorganic materials flow through rivers, upwelling processes, vertical mixing of water masses and anthropogenic sources such as agriculture, aquaculture, industry, fisheries activities, fuel use and vessel ballast water discharge disturbing the potential