The Spatial Variation of <em>Mugil cephalus</em> in the Negombo Estuary in Relation to Physico-chemical Parameters

Abstract

Analysis of physico -chemical parameters gives an insight to the spatial distribution of Mugil cephalus in Negombo estuary. The present study was carried out to the spatial distribution of Mugil cephalus that is governed by the physico -chemical parameters in bottom overlying surface water in Negombo estuary, Sri Lanka. Samplings at selected sites were done during one year study period from January 2017 to December 2017. During this study, fish (Mugil cephalus) and water samples were collected at Sea mouth, Duwa, Pitipana, Munnakkaraya, Dungalpitya, Dandugam Oya and Katunayake sites. Physico -chemical parameters such as the water temperature, salinity, pH, DO, electrical conductivity, BOD, COD and nutrients levels in the bottom overlying water were measured and analyzed using employing standards methods. The results revealed that salinity, pH, EC, BOD and nutrient levels were below the maximum permissible limits of the discharge industrial wastewater quality standards of the Central Environmental Authority (CEA), Sri Lanka. The COD levels were higher than the permissible threshold limits. The seasonality in the physico -chemical levels of water were observed with a peak period from May/June and October/November, which apparently coincided with the inter monsoonal periods of the island.

Human health risk attributed to consumption of seafood and recreation swimming in Negombo Lagoon, Sri Lanka: An assessment on lagoon water and inhabitant oysters (Crassostrea cucullata Born, 1778)

“…humid climatic regime (Cooray et al, 2021). The lagoon has a shallow depth of <5 m with dimensions spanning 12.5 km in length and 3.6 km in width (Mendis et al, 2020) (Fig. 1).…”