At least one angler is in with a chance to win $10,000 after catching one of the special green-tagged fish released into the Rotorua lakes in time for the opening of the new fishing season.

The Fish for Gold promotion centres on 30 green-tagged fish which have been put, 10 apiece, into lakes Tarawera, Rotoiti and Okataina.

The Medcalfe boys from Kawerau, Gabriel, 11, Zion, 9, and Jono, 7, proudly show off their catch at Boatshed Bay.

Numbers on the tags correspond to prizes contained in sealed and numbered envelopes and one of them contains the grand prize of $10,000. The promotion runs until October 9.

Rotorua angler Mark Preece says he and his companions were deep trolling in the white cliffs area of Lake Tarawera this morning when they hooked the green tag fish.

'It wasn't huge so we weren't overly excited – but excitement levels went up when we saw the green tag.”

Back at the Stony Point boat ramp, Mark proudly displayed his green tag popped into a plastic bag for safe keeping.

'I'm hoping it's the ten grand fish.”

On duty at the ramp, Fish & Game Officer Mark Sherburn says the fishing party had come in very excited.

'I'm quite pleased with how good the fish were looking,” he said.

Many trout had good sized smelt in their mouths or throat which indicated they were gorging on the smaller fish, which are a key food.

By mid-morning on October 1, scores of boats were out on the three lakes which have re-opened, Okataina, Tarawera and Rotoiti, anglers undeterred by the moody overcast weather conditions.

One retired fishing guide showed off his catch of five well-conditioned fish, caught at first light harling in Lake Tarawera.

Two of the biggest were handed over to visiting media to take downtown to CBK Rotorua Craft Bar and Kitchen where they were to be filmed being prepared for smoking.

Fish & Game Eastern Region Manager Andy Garrick, who had shuttled between different lakes, says there had been some scattered showers but nothing major and virtually all anglers were happy with the day.

There had been a good turnout with many folk spending the whole day on the lake, he added.

On Lake Tarawera, the ramp surveys indicated that on average the catch rate had been one fish per angler which was 'great,” with Lake Rotoiti showing similar results.

By around 5.30pm, the biggest fish caught appeared to have been a 3.6kg rainbow landed in Lake Rotoiti but several other fish had also topped the three kilo mark.

Andy says some anglers were empty handed while others did very well.

'Lots of anglers are fishing right through the weekend and Fish & Game officers will be continuing to inspect catches - so it will be next week before we have fully analysed all the data gathered.”