Fish & Game officers are preparing to quiz more than 1000 anglers about their fishing habits on opening day as the new fishing season gets underway on Rotorua's lakes.
Lakes Tarawera, Okataina and Rotoiti will reopen after a three month shutdown for spawning over winter, with more than 1200 anglers expected to try their luck.
Fish & Game officers use opening day as a major data-gathering opportunity.
They stake out boat ramps and take to the water to survey hundreds of anglers on their fishing success and methods, and weigh and measure fish.
This season the lure of a fish with a $25,000 prize tag is expected to push numbers up.
Fish & Game officer Matt Osborne said that lucky fish was one of 40 fitted with red tags released into the lakes earlier this month in the Fish for Gold promotion.
"So it's a real nail biter to see whether one of the 1200 anglers who've entered Fish for Gold can hook it by the deadline."
He said it was expected Lake Okataina would continue the trend seen over the last few seasons and produce the largest fish, due to favourable growing conditions and lower angling pressure.
Anglers across in the Auckland/Waikato region have been urged to consider the lower Waikato River as a great trout fishery if the water temperature is still below 19C.
"Trout migrate to the Lower Waikato from all over the Waipa catchment to feed on smelt and other small fish during the spring and early summer," Fisheries manager Dr Adam Daniel said.
"The lower Waikato is one of the most underused stretches of river in the region with great trout fishing in and around Hamilton for both boat and bank anglers."