CBER's invasive fish research programme

Koi carp removal from Waimapu Stream, Bay of Plenty

We boat electrofished the Waimapu Stream (176.146942°E, 37.735770°S), Bay of Plenty, following a sighting of a "large, orange fish" by an observant whitebaiter. In 2 hours' fishing on 15 April 2005, two large, sexually mature koi carp (6.9 and 7.9 kg), plus inanga, shortfin eels, yelloweye mullet, a giant bully, a juvenile lamprey macrophthalmia, a stargazer, a 1.07 m longfinned eel, brown and rainbow trout, and many common smelt were caught. No juvenile koi carp were caught, which is a hopeful sign for control of koi carp in this habitat. A further 2 hours boat electrofishing on 14 June 2005 caught no koi carp, but yelloweye mullet (Aldrichetta forsteri), not seen on 14 April, were very abundant.

Figure 1. Waimapu Stream at capture location of the two koi carp, 14 April 2005.

Figure 2. Yelloweye mullet from the Waimapu Stream, 15 June 2005.


Hicks, B.J., D.G. Bell, C.A. Ring. 2005. Boat electrofishing survey of the Waimapu and Kopurererua streams, Bay of Plenty, Waitara River, and a pond at Mokoia, Taranaki. CBER Contract Report No. 40. Client report prepared for Environment Bay of Plenty and the Department of Conservation. Centre for Biodiversity and Ecology Research, Department of Biological Sciences, School of Science and Engineering, The University of Waikato, Hamilton.