SWMBO received another accommodation request from West Island fishos for a couple of weeks next February. Just on a hunch we checked where they were intending to fish? Lake O – of course! They were not aware with the changes in regulations, so we sent them TRM’s blog prepared a year ago..
Since last season we understand over 60 Lake O enthusiasts signed a submission to the fishery managers, Department of Conservation, objecting to DOC’s decision to close the lake in February. We have not yet met any anglers who favour DOC’s new regulations. The experiment has not been successful and the February closure should be repealed immediately.
So why is Lake O so popular?
A keen TRM angler kept a simple record of 100 days fishing at Lake O from 2012 to 2016. He only stayed here during peak holiday times, during Christmas or Easter holidays, probably the worst time for excessive angler pressure. He fished off a surf ski, he only used his version of a Pheasant Tail fly and drifted around the lake at the mercy of the wind and any current. All trout were released. Not exactly a scientific analysis but his school book recorded results were outstanding. Over 100 trips, he landed 649 = 6.49 trout per visit! That is world class! If you wish to check or analyse his account, it is available at TRM reception.
Lake Otamangakau:
Recently TRM booked in a team from West Island for ten days fishing in February 2025. Just by chance, I asked them where they were planning to fish? Lake O! They were typical of many others who had not fished here since pre-covid and were unaware that DOC (Taupo Fishery Managers) had closed the lake for February. So their booking has been changed to March instead.
Some random photos of TRM’s inmates at Lake O have been added below from TRM’s library to encourage them… to indicate why it is so popular and what they can expect.
This closure continues to be strongly criticised – we have yet to find any TRM inmates who concur with DOC.
DOC of course has another story…
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.
Following blurb from “Love Taupo” website:
Lake Otamangakau
Commonly referred to as The ‘O, the Big O, or Lake O, Lake Otamangakau is one of the most-fished lakes in the Taupo Fishing District. It is only second to its much larger neighbor, Lake Taupo, which holds the surface area size of Singapore.
- Phone: +64 7 384 7106
- Email: turangi@doc.govt.nz
Fishing season: 1 September to 31 May (closed throughout February).
Despite its small size, Lake Otamangakau is known for two things: the incredible size of trophy trout and the increased number of trout in the wild fishery. Some trophy trout caught there were recorded as big as 4.5 kg, but even on a “slow” day, you can expect an average weight of 2-3 kg. Lake Otamangakau is a shallow hydro-lake formed in 1971, situated near the iconic volcanic range of the Tongariro National Park, just south of Turangi. The volcanic ranges and snow-capped peaks of Mount Tongariro and Mount Ruapehu seem so close you can reach out and touch them from your boat.
On a fateful day in 1983, a local Taupo fishing guide caught a record 8-kg trophy brown trout, cementing Lake Otamangakau as a wild trophy trout fishery, famous around the world. With the perfect storm of ideal conditions like current flow, cold water temperatures, and oxygen levels, trout thrive and return season after season to spawn here.
The fishing season now begins 1 September through to 31 May (closed throughout February). But some of the best fishing is in early Summer when there are plenty of cicadas for trout to feast on. If you’re going to catch and release, your best chance is to fish on either side of peak summer when the waters are cooler for fish to the surface.
Because the lake is so shallow and has two boat access ramps, it makes it a premium spot to fish from a small pontoon boat, jigging or casting your fly in the most remote weed beds and banks. It’s recommended to stay away from wading as the muddy holes and silt can sneak up on you.
At Lake Otamangakau, you can enjoy some of the best wild trout fishing in New Zealand and some of the best natural scenery the North Island has to offer.
Learn more about Taupo fishing regulations here, grab your fishing license, and get out on the water!
Fishing regulations for Lake Otamangakau
- Fishing Season: 1 September – 31 May (closed throughout February)
- Fishing License: Required
- Boat fishing: Yes
- Bag limit: 2
- Size limit: 35 cm minimum
