Koi carp hunting comp sees four tonnes of pest fish removed from Waikato river catchment

The New Zealand Bowhunters Society removed more than four tonnes of pest fish koi from the lower Waikato River catchment over the weekend. Photo / Waikato Regional Council

Forget pigs, goats, ducks and deer, the New Zealand Bowhunters Society has been hunting fish in the name of biosecurity.

As part of the 33rd World Koi Classic competition, members of the society helped remove more than four tonnes of pest fish koi from the lower Waikato River catchment.

The event was supported by the Waikato Koi Management Programme, a partnership between Waikato Regional Council, the Department of Conservation, Waikato River Authority and Te Riu o Waikato.

DoC Freshwater technical advisor Nigel Binks said koi were commonly seen in the lower Waikato River system and regarded as a pest because their foraging behaviours degrade the quality of freshwater habitats and impact the survival of native species.

“Removing koi helps to reduce the impact of this species on native aquatic plants, fish, and invertebrates, and is important for the protection of quality habitats needed by native fish, such as long and short finned eels, black mudfish, inanga, and giant kokopu,” said Binks.

Over 40 competitors took part in the Koi Classic, shooting a total of 4113kg of koi over two days, with weigh-ins at the Ohinewai Hall.

Andrew Cottle and Sam Walter, pictured with DoC Freshwater Pests and Migratory Fish Species ranger Anita Pearson, shot a record total of 1092.09 kilograms of koi in the Whangamarino wetland. Photo / Waikato Regional Council

There were a couple of titles to win: Heaviest koi, most total kills, most fish per team and smallest carp.

The winning team, hunters Andrew Cottle and Sam Walter shot a record total of 1092.09kg of koi in the Whangamarino Wetland, 865kg of koi on one day alone.

The largest koi caught in the competition weighed 5.8kg and the smallest carp was just 200g.

Te Riu o Waikato Board Chair Tawera Nikau said all koi caught would be processed by their organisation into pet food, fish bait Berley and organic soil fertiliser.

While the competition was an excellent resource for koi management, there were also a couple of biosecurity risks to consider for the hunters, but DoC and the regional council were there to assist.

Michelle Archer, Waikato Koi Management Programme workstream lead for Waikato Regional Council, said there were a number of invasive aquatic species, including koi, gold clam and aquatic weeds, that bowhunters could inadvertently move around on their gear or by boats and trailers.

“Efforts to prevent the spread of aquatic pests included full checks of all equipment, a wash-down (hot water or bleach for absorbent materials) and the thorough drying of all gear.”

Mana whenua Ngā Muka also supported the event by assisting the bowhunters with advice to ensure the event worked within the requirements of the rahui on Whangamarino Wetland.

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