PULP MILL-SOURCED SUBSTANCES IN SEDIMENTS FROM A COASTAL WETLAND

Matata Lagoon, at the mouth of the Tarawera River is an ecologically i mportant coastal wetland, situated some 26 km upstream of two paper mi lls which discharge their waste waters into the river. A matter of env ironmental concern is the extent to which pulp mill related organic su bstances, especially resin and fatty acids, have penetrated the upper and lower reaches of the lagoon. Investigation by GC-FID and GC-MS est ablished that: (1) the lower lagoon sediments possessed resin acid lev els similar to that presently within the river bed; (2) upper lagoon s ediments were close to natural background levels; and (3) mass spectra l ion ratio analyses confirmed that lower lagoon sediments were signif icantly contaminated by mill-sourced resin acids, whereas upper lagoon sediments were not significantly contaminated.