Common Carp

Habitat Distribution

• Introduced — not native. First feral breeding population confirmed in the Waikato River in 1983; now common throughout the lower Waikato system and its associated lakes.
• Scattered populations exist across the North Island, including Northland and Wellington; a small South Island presence near Nelson has been largely eradicated.
• Favour still or slow water: shallow lakes, oxbow lakes (riverine lakes), backwater channels, ponds and sluggish river margins.
• Highly tolerant of poor water quality — low oxygen, high turbidity and warm temperatures that would stress most other species.

Key Locations

• Lower Waikato River and its oxbow lakes — the core of the New Zealand population; fish are numerous and run large.
• Lake Hakanoa (Huntly) — a well-known North Island koi fishery with easy access and good numbers of fish.
• Lake Ngaroto and Lakes Waahi and Waikare — Waikato region lakes holding established populations of decent-sized fish.
• Lake Rotoroa (Hamilton Lake) — urban lake in Hamilton with koi present alongside tench and other coarse species.
• Scattered North Island streams and ponds around Auckland, including the Waikato tributary network — fish have spread widely through flood events and illegal releases.

Specific Spots

• Shallow, muddy-bottomed bays and margins where fish root through the substrate — look for clouded water and bubbles rising from the bottom as feeding signs.
• Weed edges and reed beds: koi use dense vegetation for cover and forage along the edges, especially in the warmer months.
• Warm, sheltered backwaters and lake arms that heat up quickly in spring — fish congregate here well before open water warms.
• River confluences and canal mouths where slow water meets a slight current, concentrating food and drawing fish to feed.