Hawke's Bay Fish and Game officers are keeping a close eye on the algal bloom problems at Lake Tutira but believe there is no threat to the lake's trout population.
Officer Tom Winlove said there had been some speculation about the impact of the algal bloom on the 2750 young trout released into the lake in September.
"There have been no reports or evidence to suggest that fish are dying in any numbers which fits with what's happened when previous blooms have occurred.
"And the Hawke's Bay Regional Council has found that overall, water quality hasn't been impacted [in the lake]."
Mr Winlove said there was no doubt the lake was experiencing one of the worst algal blooms of recent times but he was optimistic for the trout's survival, based on what's occurred in past years.
"While we're not trying to downplay the situation, people do need to keep things in perspective and take account of the fact these blooms occur annually, with little impact on fish populations."
Fish and Game said it could be assumed that the "nice healthy fish" caught last winter had been exposed to a bloom as young fish with no apparent ill effects.
"We do of course support the advice of health officials and scientists at the Hawke's Bay Regional Council. Don't eat the fish while the bloom is present."
Mr Winlove said Fish and Game did not see any reason for anglers to stop fishing if they could find clear water at the lake, as long as they took reasonable precautions to reduce their contact with the water.
Normal fishing waders should provide enough protection, it said.
"Fish and Game is happy to advise anglers about fishing the lake but health-related questions should more properly be directed towards the health authorities and the council."