Freshwater Quality

The SHMAK method for rubbish involves collecting and identifying all the rubbish (litter) in the stream and on the stream banks. It was designed to complement rubbish assessments on our beaches so the data is comparable.

There are two methods for describing streambed composition: the visual assessment method is quicker while the Wolman walk is more accurate.

Before you can start looking at what animals you have collected, you have to clear as much debris away from your sample as you can. You should follow the methods here if you have a lot of debris (stones, sand, leaves, twigs) in your net after you sample. When you enter your data into the NZ Water Citizens website - https://nzwatercitizens.co.nz/ - you can use the online calculator to calculate a health score.

A net allows you to collect a greater range of benthic macroinvertebrates and more accurately assess the diversity of the community. The kick-net method (or scuff method) shows you how to dislodge the stones on the streambed and collect the invertebrates living on or in-between them. When you enter your data into the NZ Water Citizens website - https://nzwatercitizens.co.nz/ - you can use the online calculator to calculate a health score.

Macrophytes are large aquatic plants. You don’t need any specialised equipment to assess macrophyte cover, just a measuring tape and a willingness to get into the stream if you can’t see the bottom.

Phosphate is measured in SHMAK using the Hanna Instruments Phosphate Checker. You can order additional phosphate checkers or just the chemical reagents here https://www.mediray.co.nz/

Temperature and conductivity are two easy measurements you can take in your stream. Options for continuous temperature monitoring using a temperature logger are given.

Some SHMAK tests require you to collect a water sample. If you are sending your water sample to a lab for analysis, a list of some water quality labs is given below.

The various assessments in SHMAK are done over different lengths (reaches) of stream. Follow the steps in the video in order to mark out the longest reach first, then shorter reaches.