In New Zealand, Greater Wellington and Wellington City Council (WCC) are conducting a survey of contaminants in Wellington Harbor to determine the harbor’s health. The survey is running during November and follows an assessment previously conducted in 2006. It is designed to assess how urban storm water is affecting the quality of the sediment on the harbor seabed as well as the health of the sediment-dwelling animals living there.

Surface sediment and benthic invertebrates will be collected from 16 sites near Lambton Harbor, Aotea Quay, Evans Bay and the Petone foreshore. The sediment samples will be analyzed for a range of contaminants, including heavy metals, polycyclic aromatic hydrocarbons (PAHs, which are byproducts of fuel burning) and pesticides. The baseline assessment from 2006 showed that heavy metals, PAHs and pesticides have accumulated in the sediments of Wellington Harbor, with the highest concentrations found in inner Lambton Basin and Evans Bay, where there is less flushing of contaminants.

Investigations show that urban storm water, which can contain toxic chemicals such as paint and oil, copper from vehicle brake pad wear, and zinc from unpainted galvanized roofs, is a major contributor to the contamination. While some contamination is historical in origin, such as lead from leaded petrol, the contaminants are persistent and toxic and continue to enter the harbor via streams and storm water outfalls.

The survey is being coordinated by Greater Wellington’s Environmental Monitoring and Investigations Department and is co-funded by WCC and Hutt City Council. WCC is required to monitor sediment quality every five years at a number of the sites as part of a new consent granted earlier this year that covers all of Wellington city’s storm water discharges into the harbor.

Source: Greater Wellington Regional Council

(Source: https://www.stormwater.com/home/news/33049574/new-zealand-survey-underway-to-study-health-of-animals-sediment-in-wellington-harbor)