He said the most fish found in the trap in a single morning this winter was 30 and the heaviest fish weighed in, so far, reached the 4kg mark.
Mr Sherburn said with trout fishing, it was a case of "swings and roundabouts" and some anglers were doing better than others.
He said Lake Rotoiti continued to be one of the lakes producing some of the larger fish.
"The winter shoreline fishing at locations such as Ruato Bay is in full swing and our staff have already weighed in a number of trophy fish."
He said a dark night, bad weather and an onshore breeze were the best conditions for this type of fishing.
"Clear, still conditions with a bright moon tend to limit success, so pick your nights for the best results."
Shallow harling, a method known to work in spring and autumn, is also producing several catches on many of the lakes.
"A large smelt fly trolled slowly along the weed beds is hard to resist for hungry trout at this time of year."
The upper Ngongotaha Stream has just a few weeks to run before it closes over winter.
"Anglers have been encouraged by some great runs of brown trout here. It's worth remembering that the lower section and mouth of the Ngongotaha below SH5 is open year-round to spinning and fly fishing."
Meanwhile, Fish and Game Officer Matt Osborne, who oversees dives to count fish numbers, said a recent dive at the Tarawera outlet produced some "pleasing results".
Mr Osborne said it was normal to see fewer than 200 adult fish diving there in May, but on this occasion they saw more than twice that number - 590 large rainbow trout.
"And the peak of spawning is yet to come - in June or July," he said.
"The fish do seem to be spawning earlier as a result of climatic conditions, and as seen in the number of fish coming from the Te Wairoa trap."