Assessment of bio-accumulation of bacteria in oysters from shellfish growing waters in Ashtamudi Lake (Kerala, India): A RAMSAR wetland

Abstract

h i g h l i g h t s• In India, this is the first-ever assessment, which offer an insight on the accumulation of bacteria in farmed oysters.• We investigated the dynamic process of microbial bio-accumulation and how it is influenced by rainfall.• Bio-accumulation was high during the pre-monsoon season when the Lake is brackish.• Salinity and temperature play a major role in the survival of coliform bacteria in the shellfish growing water.• We can reduce input costs in the laboratory by analysing faecal coliform as a quality indicator instead of using E. coli as an indicator. a r t i c l e i n f o

Assessment of Bacterial Accumulation and Environmental Factors in Sentinel Oysters and Estuarine Water Quality from the Phang Nga Estuary Area in Thailand

“…The seasons that correlate with high RH and high air temperature are during southern Thailand’s summer (Feb–May) and rainy (May–October) season. These observations are consistent with the findings from Kerala, India, where there was strong negative correlation (R 2 = −0.7) between the EC levels and seawater temperature within a range of temperatures from 26–32 °C [ 35 ]. One mechanism to explain these findings is that a main inactivating factor for EC survival in brackish waters was sunlight [ 41 ], which tends to be high during summer.…”

“…For example, for each additional increase of 100 FC in oyster meat, levels of EC increase by ~1.015-fold (or 1.5%, e (0.000149×100) = 1.015). Monitoring FC levels rather than EC might function as a reliable indicator of shellfish quality and further reduce costs of surveillance due to cheaper assays compared to EC analysis [ 20 , 35 ]. Levels of EC in oysters varied substantially with the amount of average precipitation during the previous 7 days.…”

Factors Influencing the Concentration of Fecal Coliforms in Oysters in the River Blackwater Estuary, UK

“…The results largely reflect the results obtained for FS in water (Figure 2A). It has been reported that shellfish accumulate coliforms from the shellfish growing waters and then maintain these levels for long periods [24,25]. In this study, there were no significant differences (p > 0.05) in either E. coli or FS numbers between water and oysters sampled on the same dates suggesting that uptake by oysters was linked to the number of FS or E. coli present in the overlying waters.…”

Baseline health risk assessment of trace metals in bivalve shellfish from commercial growing areas in the estuaries of Ashtamudi and Vembanad (Kerala, India)

“…The yellow-foot clam, the green mussel and the edible oyster are widely harvested for human consumption in Kerala estuaries (Chinnadurai et al, 2016 and2020). These shell sh provide high quality protein with essential amino acids for maintenance and growth of the human body and are therefore good complements of a healthy diet for local communities ( 1 World Health Organization (1993).…”