Lake Otamangakau
Image: DOC

Archived content: This media release was accurate on the date of publication. 


The ‘Anglers Notice for the Taupo District 2022’ confirms changes will be in place at Lake Otamangakau when it opens again on the 1 September 2022.

Date:  22 June 2022

Regulation changes

Four regulation changes aim to protect the long-term future of this iconic trout fishery.

  • The season at Lake Otamangakau will start a month earlier from 1 September.
  • Lake Otamangakau will close to trout fishing during February – the hottest month of the year.
  • A maximum takeable size of 55 cm for trout will be introduced. There will be no minimum takeable size.
  • The bag limit will be reduced to two trout.

DOC Operations Manager Taupō Fishery Dave Conley said, “We are pleased to see support for these important changes which we firmly believe are needed to protect the future of Lake Otamangakau, particularly during the hottest time of the year where elevated water temperatures pose a threat to trout.

“Our technical team, led by Fishery Scientist Dr Michel Dedual, carried out a robust investigation over a two-year period which pulled together data from multiple studies, as well as listening to feedback from anglers. The result was a clear set of proposals backed by solid scientific evidence.” 

Why change

The scientific work was triggered by increasing feedback from anglers who reported seeing dead trout in February, when water temperature is at its highest. It was also informed by the ongoing debate within the angling community around encouraging trophy trout at Lake Otamangakau.

Changes to the fishing season are designed to help protect large trout when they are vulnerable to heat stress. Catch-and-release is a popular approach used by anglers at Lake Otamangakau. The warm water phase of our research confirmed trout only had a 60 percent survival rate when released in these conditions, therefore stopping fishing during the hottest month of the year will reduce unnecessary trout mortality.

The new maximum takeable size and reduced bag limit will help protect larger trout. Spawning trap data confirms trout at Lake Otamangakau continue to grow beyond their maiden spawning year. In simple terms, the longer they live the bigger they get. Protecting larger specimens will allow them to grow even bigger and increase the opportunity for anglers to catch fish over 10 lbs (4.5 kgs).

Supporting information

A report analysing the scientific data and detailing management options was released in December 2021: Lake Otamangakau: Research update 2021

The Anglers Notice for the Taupo District 2022 can be found on the New Zealand Gazette website.

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