Trout numbers in three Bay of Plenty lakes have taken an upward leap with Fish & Game officers releasing the first of 6,500 rainbow trout for November.

Officers began their 'liberations” at Lake Tarawera on Tuesday, releasing 2500 yearlings into the water.

Fish & Game Officer Lloyd Gledhill pipes hundreds of fish into Ruato Bay, Lake Rotoiti.

Yesterday another 3500 fish were piped into Lake Rotoiti at various locations including Ruato bay. Another 500 fish will be delivered to Lake Okataina next week.

The fish are transported in oxygenated tanks aboard the hatchery's ‘live trout truck' – and the release of hundreds of wriggling fish in the shallows usually draws at least a few curious onlookers.

Fish & Game Officer Mark Sherburn says the releases are carried out in a series of smaller 'staggered” batches over a longer timeframe than in earlier years.

The method achieves better survival rates of the juvenile trout.

So far this year almost 70,000 yearlings have been released into the lakes around Rotorua to ensure that catch rates are up to a high standard.

The rainbow trout released this month won't be of a catchable size until next year.

'But no worries,” says Mark. 'The same number of trout were released this time last year too so there will be plenty to catch over the summer!”

Inside one of the trout truck's oxygenated tanks.