Who has mud on their hands? A bootstrapping technique for determining a fingerprint for sediment tracing in the Whangapoua Harbour

Judith L. McWhirter
University of Waikato

Brendan Roddy
University of Waikato

Removal of soil from the earth's surface by wind and water and subsequent delivery to streams and rivers is a natural process that operates over geological time scales. Human land use activities such as agriculture and silviculture hasten this process and can increase the erosion. The sediment is delivered to streams, where the suspended fraction is richly organic and also transports bound nutrients and chemical pollutants. These then impact plant, fish and invertebrate communities; the physical and chemical characteristics of the streams and estuaries; as well as the physical appearance of these water bodies. In the New Zealand context, estuaries are the most impacted of all coastal waters and have water quality issues relating from the surrounding land uses, but sediment fingerprinting has rarely been used to determine the source.

We discuss an innovative bootstrapping technique which allows for the fingerprinting of sediment samples to their source areas so that the relative importance of these sources can be determined. We report the results from a pilot study undertaken in 2006 where it was concluded that the technique of sediment fingerprinting could distinguish between source areas based on land use (native forest, exotic forest, agriculture) in the Waitakuri River catchment.

Session 3b, Biometrics: 13:30 — 13:50, Room 445

Presentation Program