Resurvey of Antifouling Co-Biocides

The Council assisted, by way of sample site selection and sample collection, in the 2006 resurvey of antifouling co-biocides in New Zealand coastal waters. The survey, and reporting, was done by Carol Stewart for the Ministry for the Environment and followed up from the 2003 national survey of levels of the antifouling co-biocides; Irgarol 1051 and Diuron, in New Zealand's coastal waters and sediments.

In Northland, samples were collected on 9 February 2006 from the following coastal sites; Parua Bay jetty in Whangarei Harbour, Town Basin marina in Whangarei and Doves Bay Marina in the Bay of Islands. Samples were also collected from the following freshwater sites for comparison; Kapiro Stream at Purerua Road, Wairoa Stream at Cobham Road and Raumanga Stream in Whangarei.

Aerial photo of the Town Basin marina in Whangarei.Aerial photo of the Whangarei Town Basin Marina, one of the sampling sites used in the 2006 resurvey.

Northland's coastal results were consistent with findings elsewhere in New Zealand for the 2006 survey. That is, measurable concentrations of the co-biocide Diuron were found at sampling sites within areas of high density mooring (i.e. Marinas) and Irgarol 1051 was not detected at any of the sampling sites. Overall contamination of these co-biocides in Northland's coastal waters was considered to be a problem of limited extent.

For more information contact Ministry for the Environment and quote the following report: ‘Antifouling co-biocides in New Zealand coastal waters: 2006 resurvey' produced by Carol Stewart for the Ministry for the Environment.