Evaluation of a traditional Māori harvesting method for sampling kōura (freshwater crayfish, Paranephrops planifrons) and toi toi (bully, Gobiomorphus spp.) populations in two New Zealand streams. Issue 4 (2nd October 2018)

• Record Type: Journal Article
• Authors: Kusabs, Ian A.; Hicks, Brendan J.; Quinn, John M.; Perry, William L.; Whaanga, Hēmi
• Is Part Of: New Zealand journal of marine and freshwater research. Volume 52:Issue 4(2018)
• Page Start: 603
• Page End: 625
• Publication Date: 2018-10-02
• Subjects: Whakaweku -- Mātauranga Māori -- optimum soak time -- representative catch data -- freshwater crayfish trap -- Bracken fern bundles; Marine biology -- New Zealand -- Periodicals; Freshwater biology -- New Zealand -- Periodicals; Freshwater biology; Marine biology; New Zealand; Periodicals; 578.77099305
• DOI: 10.1080/00288330.2018.1481437
• Languages: English
• ISSNs: 1175-8805

Abstract

ABSTRACT: Representative sampling of crayfish in streams is often impractical, especially in non-wadable habitats, or in areas with soft substrates. Whakaweku are artificial habitats made from bracken fern ( Pteridium esculentum ) that can be used successfully in a range of habitats. We compared whakaweku, minnow traps, fyke nets and electrofishing for sampling freshwater crayfish (kōura; Paranephrops planifrons ) and bullies (toi toi; Gobiomorphus spp .) in two streams with differing stream characteristics and fish assemblages. Whakaweku captured a full-size range of kōura of both sexes, including small kōura (OCL 7–12 mm) that were not caught by minnow traps or fyke nets. Colonisation by kōura reached 90% of maximum after 2 weeks and CPUE was constant from 2 to 9 weeks. After 9 weeks, CPUE decreased due to decay of the fern fronds. Whakaweku are an effective sampling tool that are inexpensive, simple to set, and do not require expensive equipment or specialised training.