New ways to detect contamination of muddy flood plumes in coastal waters

Embargoed until: Publicly released: 2022-07-08 03:00

New Zealand

Wellington Harbour, Creative Commons - CC BY 2.0 - https://commons.wikimedia.org/wiki/File:Wellington_Harbour,_New_Zealand,_Nov._2009.jpg

After a flood, muddy contaminated plumes are discharged into the sea from rivers, posing a hazard for swimmers and shellfish. A New Zealand research team used a new way of sampling from a fast boat to map a flood plume in Wellington Harbour, while at the same time sampling source water from the Hutt River. Faecal contamination - indicated by E. coli bacteria - correlated closely with various measures that can help to monitor plumes, including salinity, sediment and coloured dissolved organic matter. The team says these easily-detected tracers could indicate worst-case (invisible) faecal contamination in satellite imagery. Rapid plume surveys, combined with long-term river observations, could usefully add to routine coastal water monitoring, they say.

News release

From:

Journal/
conference: New Zealand Journal of Marine and Freshwater Research

Research:Paper

Organisation/s: National Institute of Water and Atmospheric Research (NIWA)

Funder: Manuscript preparation was funded by SSIF project FWCE2201, ‘Microbial pollution of estuaries’ (led by RD-C) with a contribution from FWWQ2206, ‘Nowcasting of recreational water quality’ (led by RS). Experimental work was funded by several projects through NIWA’s Freshwater and Estuaries Centre via the Strategic Science Investment Fund (SSIF) from Ministry of Business Innovation and Employment (MBIE).

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