Tidal fluctuations influence E. coli concentrations in urban estuaries

Dusan Jovanovic; Rhys Coleman; Ana Deletic; David T McCarthy

doi:10.1016/j.marpolbul.2017.04.004

Tidal fluctuations influence E. coli concentrations in urban estuaries

Mar Pollut Bull. 2017 Jun 15;119(1):226-230. doi: 10.1016/j.marpolbul.2017.04.004. Epub 2017 Apr 10.

Authors

Dusan Jovanovic¹, Rhys Coleman², Ana Deletic³, David T McCarthy⁴

Affiliations

¹ Environmental and Public Health Microbiology (EPHM) Laboratory, Monash Infrastructure Institute, Department of Civil Engineering, Monash University, Clayton, Victoria 3800, Australia. Electronic address: dusan.jovanovic@monash.edu.
² Melbourne Water Corporation, Docklands, Victoria 3008, Australia. Electronic address: rhys.coleman@melbournewater.com.au.
³ Environmental and Public Health Microbiology (EPHM) Laboratory, Monash Infrastructure Institute, Department of Civil Engineering, Monash University, Clayton, Victoria 3800, Australia. Electronic address: ana.deletic@monash.edu.
⁴ Environmental and Public Health Microbiology (EPHM) Laboratory, Monash Infrastructure Institute, Department of Civil Engineering, Monash University, Clayton, Victoria 3800, Australia. Electronic address: david.mccarthy@monash.edu.

PMID: 28396075
DOI: 10.1016/j.marpolbul.2017.04.004

Abstract

This study investigated the influence of water level and velocity on Escherichia coli levels over multiple tidal cycles in an urban microtidal estuary in Melbourne, Australia. Over 3,500 E. coli samples and high resolution water level and velocity measurements from two locations within the estuary were used for the analysis. E. coli negatively correlated with water level in the upper estuary which was proposed to be linked to increased resuspension of estuarine sediments during low tide. No relationship was found in the lower estuary, likely due to wet weather inputs dwarfing subtler tidal-related processes. Removal of wet weather data enabled significant relationships to emerge in the lower estuary: 1) positive with water level (when a 9-h shift applied corresponding to the phase shift between water levels and velocities) and; 2) positive with velocity (no shift applied). This supports a link between increased E. coli levels and tidal-related resuspension.

Keywords: Distribution; Flow velocity; Pathogens; Tidal currents; Tidal stage; Water level.

MeSH terms

Australia
Cities
Environmental Monitoring
Escherichia coli*
Estuaries*
Water Movements
Weather