Ponmani, M.; Manimekalai, D.; Padmavathy, P.; Parthiban, F., and Manickavasagam, S., 2023. Spatial variations of hydrocarbon-degrading bacteria in relation to physicochemical parameters along the coastal waters of Thoothukudi (India). Journal of Coastal Research, 39(5), 869–879. Charlotte (North Carolina), ISSN 0749-0208.
The present study involves collecting seawater and sediment samples from two different locations along the Thoothukudi coast, namely the fishing harbour and the dry-docking yard, to analyse physicochemical parameters and bacterial abundance. Total heterotrophic bacteria, total hydrocarbon utilizer, total naphthalene utilizer, total phenanthrene utilizer, organic carbon, and physicochemical parameters were all analysed from the collected water and sediment samples to determine the condition and quality of the waters and sediments. Maximum counts of total hydrocarbon utilizers (15.5 × 104 cfu/mL), total naphthalene utilizers (8.5 × 104 cfu/mL), and total phenanthrene utilizers (11.8 × 104 cfu/mL) were observed in fishing harbour waters. The highest total heterotrophic bacteria counts were found in fishing harbour sediments (15.5 × 105cfu/g). Maximum counts of total heterotrophic bacteria and minimum counts of total phenanthrene utilizers were observed in dry-docking yard water and sediments. Higher bacterial counts were found in the fishing harbour with a high concentration of oil and grease, as well as other environmental parameters. A significant positive correlation (P < 0.05) was found between the bacterial population of oil and grease and organic carbon. This investigation revealed that the water column contains oil and grease, which promotes the growth of hydrocarbon-utilizing bacteria, as well as organic matter, which promotes the growth of heterotrophic bacteria. The current study found that bacterial populations had a positive correlation (P < 0.05) with the suspended matter, indicating that anthropogenic activities dominated the coastal areas of the Thoothukudi coast.
