Dispersion and retrievability of water quality indicators during tidal cycles in coastal Salaya, Gulf of Kachchh (West coast of India)

National Institute of Oceanography, Dona Paula, Panaji, Goa, 403 004, India.
Environmental Monitoring and Assessment (Impact Factor: 1.68). 10/2009; 169(1-4):639-45. DOI: 10.1007/s10661-009-1203-3
Source: PubMed


Bacterial indicators in relation to tidal variations were studied at five locations for over 2 days covering three tidal cycles in the southwestern region of Gulf of Kachchh, India. Tidal flow here is predominantly in the east west direction and can transport particles up to 32 km. Tidal amplitude appears to play a prominent role in abundance, distribution, and dispersal of coliform bacteria examined during this study. Shallow depths, clayey sediments, strong currents, and higher tidal amplitudes appear to rise by an order of magnitude in total bacterial abundance up to 2.4 x 10(4) ml(-1) due to their resuspension from the churned up sediments. Dispersal of allochthonous microflora far into coastal marine regions appears to be governed by the strong tidal amplitude in this region.

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    • "Sediments may contain 100 to 1,000 times the number of fecal indicator bacteria than the overlying water layers (Ashbolt et al. 1993b). As a result, bacteria levels increase by resuspension of sediments (Byamukama et al. 2005; Mohandass et al. 2010). Co-sedimentation, i.e., the joint deposition of sediment particles and bacteria is a most common way, bacteria will settle in running waters. "
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