Gathering shellfish in Nelson

Shellfish are filter feeders. They take their food from the surrounding water. In doing so they can also take in various types of contamination from the surrounding water. Contaminants tend to accumulate in the shellfish often to levels greater than that of the surrounding water.

Contamination

There are many potential sources of contamination from human activities and from animals within urban areas.

During periods of heavy rain, contaminants such as animal droppings are washed into rivers, streams and stormwater systems and from there into the sea.

Where an urban area is located at the head of a bay or within an estuary (like Nelson) contaminants released to the coast do not dilute as quickly and tend to stay in shore for longer periods. This leads to a greater likelihood of the contaminants being picked up and accumulated by shellfish in the area.

Through Project Maitai, Council is working to reduce contamination of stormwater entering Tasman Bay from the Maitai River Catchment, but in the meantime shellfish should not be taken from within the enclosed waters of the Waimea Inlet and the Nelson Haven as they may exceed maximum microbiological guideline levels.