Peter Jessup: Cold puts fish off bite

The cold, windy weather has put a stop to what was a promising start to the season, with the water temperature dropping considerably in the past week.

Off the Coromandel Peninsula, Dave "Mavis" Bryant, from Coromandel Safaris, reports that water temperature fell from 16.8C to 14.5C off Great Mercury Island. In the Bay of Islands, Geoff Stone on Major Tom II said temperatures had reached 20C but were back down as low as 16C.

All of which has put the snapper off the bite and stalled what looked like an early start to the billfish season after Stone landed the first gamefish for 2004/05, a 90kg striped marlin taken on 15kg line.

Bryant said the fishing was great last week, with big kingfish showing up and plenty of snapper, but the wind put paid to it.

The Mercury Bay Ocean Sports Club held its Icebreaker tournament at the weekend, with 58 anglers landing only two snapper - 11kg and 9kg.

Around Auckland it's been the same. Lance Paniora, on Smokin' Reels, has been out most days but the fishing's been hard.

The snapper are still there, with good marks on the sounder and fish up to 5kg coming into the channels. But it has not been comfortable fishing.

At Lake Taupo, the trout fishing has also gone cold with the blustery southerly sending smelt back to deeper water.

The Department of Conservation has completed its annual count of large trout, which shows that fish numbers are well down. Since 1988, the department has conducted an acoustic survey to find the number of fish over 35cm. The count has fluctuated between 60,000 and 150,000, according to a variety of environmental factors.

Volcanic eruptions and last year's floods clouded things.

Changes also follow feed cycles, with the size of the smelt run determined by which type of phytoplankton is dominant in the lake.

This year, the number of large fish is around 60,000. But there is no cause for alarm because large numbers of spawning run fish are still in the rivers and the general size of juvenile fish is lower than usual because of the late spawn.

There had been late spawning for the past five years, said DoC fisheries technical support programme manager Glenn Maclean, and the offspring in the lake were several months younger than usual for this time of year.

These fish in turn breed later, hence the late spawning run. Spawning peaked in October but large numbers of fish are still being caught in the Waipa trap. The good news is they are generally in the 2-2.2kg range and are in very good condition.

The fish grow 1mm a day, 3cm a month. The acoustic survey showed that there are few big fish in the middle of the lake, most concentrated around the edges. That's the good news.

But they've stopped feeding hard without the smelt run to encourage them and that's the bad.

It's been the same at the Rotorua lakes, where it had previously been a cinch to get your bag limit by trolling in the shallows. Warmer water at the lake edges will set it off again. Likewise the snapper spawning and the following feeding frenzy.