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Evaluating techniques for sampling stream crayfish (paranephrops planifrons)

Abstract
We evaluated several capture and analysis techniques for estimating abundance and size structure of freshwater crayfish (Paranephrops planifrons) (koura) from a forested North Island, New Zealand stream to provide a methodological basis for future population studies. Direct observation at night and collecting with baited traps were not considered useful. A quadrat sampler was highly biased toward collecting small individuals. Handnetting at night and estimating abundances using the depletion method were not as efficient as handnetting on different dates and analysing by a mark-recapture technique. Electrofishing was effective in collecting koura from different habitats and resulted in the highest abundance estimates, and mark-recapture estimates appeared to be more precise than depletion estimates, especially if multiple recaptures were made. Handnetting captured more large crayfish relative to electrofishing or the quadrat sampler.
Type
Journal Article
Type of thesis
Series
Citation
Rabeni, C.F., Collier, K.J., Parkyn, S.M. & Hicks, B.J. (1997). Evaluating techniques for sampling stream crayfish (paranephrops planifrons). New Zealand Journal of Marine and Freshwater Research 31(5), 693-700.
Date
1997
Publisher
RSNZ Publishing
Degree
Supervisors
Rights
Copyright New Zealand Journal of Marine and Freshwater Research. Used with permission.