Step One: first, determine if kōura should be present in your stream.
Talk with local scientists, kaumatua, kaitiaki, anglers, eel fishers and others, about their memories and current interactions with kōura. A search of records in the New Zealand Freshwater Fish Database will reveal what sampling has been carried out in the vicinity of your stream, provide data on kōura found to date, and highlight what sampling methods were used. If no data are available, or the data are limited, a field survey (see below) may be necessary to determine whether kōura are present.
If a field survey is required then there are a number of methods that can be used, the most suitable method will depend on habitat type and available resources. For example, electric fishing is useful in small streams but requires specialised equipment and trained operators and is not suitable for use in lakes or large rivers.
Determine the most suitable method for sampling kōura in lakes (and other lentic habitats). Research has shown that the tau kōura, a traditional Māori fishing method, commonly used to harvest kōura has advantages over many other methods. For more information on the tau kōura see Background on traditional and modern use of tau kōura.
For advice on how to survey kōura in lakes and streams using the tau kōura method, see Tau kōura sample collection and processing protocol. Rabeni et al. (1997) evaluated several standard capture and analysis techniques for estimating abundance and size structure of kōura from a small, forested stream. For more information on sampling kōura in small to medium sized streams, see their 1997 paper Evaluating methods of sampling stream crayfish.