New Zealand Journal of Marine and Freshwater Research abstracts

---

Population structure, individual movement, and growth rate of shortjaw kokopu (Galaxias postvectis) in two North Island, New Zealand streams

Richard Allibone*

National Institute of Water and Atmospheric
 Research Limited
P.O. Box 11 115
Hamilton, New Zealand

*Present address: Biodiversity Recovery Unit, Department of Conservation,
P.O. Box 10 420, Wellington, New Zealand. email: rallibone@doc.govt.nz

Dean Caskey

Department of Conservation
Stratford, New Zealand
email: dcaskey@doc.govt.nz

Rosemary Miller

Department of Conservation
Private Bag 3016
Wanganui, New Zealand
email: rmiller@doc.govt.nz

Abstract  The shortjaw kokopu (Galaxias postvectis), although widely distributed throughout New Zealand, is only known from a few sites and generally with extremely low population numbers. Two sites in Taranaki (Katikara Stream and Stony River tributary) were found to contain relatively high densities of shortjaw kokopu. These sites were monitored at 6-monthly intervals over 3^1/₂ years to gather site fidelity and growth rate data. Half-way through the sampling period the riparian vegetation alongside the Katikara Stream site was destroyed. Although this was unfortunate, it allowed examination of the impact of a disturbance event of this nature on shortjaw kokopu growth and behaviour. The density of shortjaw kokopu in Katikara Stream was about twice that in the Stony River tributary, whose population was characterised by fewer but larger individuals. Growth rate was significantly greater for smaller fish, and varied between the two sites. Fish in the Katikara Stream were generally site loyal with only a small percentage of mobile fish; however, greater movement from sites was noted immediately after the disturbance event.

Keywords  shortjaw kokopu; Galaxias postvectis; galaxiid; growth; threatened; habitat; disturbance; movement; New Zealand

M02067 Received 28 August 2002; accepted 11 June 2003; Published 5 August 2003
New Zealand Journal of Marine and Freshwater Research, 2003, Vol. 37: 473-483
0028-8330/03/3703-0473 $7.00 © The Royal Society of New Zealand 2003

PDF file of entire paper: Print-quality (293K) | screen-quality (106K)

---

This year's abstracts | Journal home page | All abstracts | Publishing home page