Eastern Region Fish and Game Council chairman Ngahihi Bidois. Photo / Andrew Warner
Eastern Region Fish and Game Council chairman Ngahihi Bidois. Photo / Andrew Warner
The holiday season's sweltering heat has "surprisingly" brought great news for Rotorua's fishermen and women as the city's main lakes reach high temperatures earlier than usual.
Bay of Plenty Regional Council's water quality monitoring website recorded surface temperatures on Lake Rotorua of 26.55C on Wednesday.
Fish & Game Eastern Regionofficer Mark Sherburn said such temperatures were hot for trout.
"Trout need cool water temperatures to survive, but perhaps surprisingly, these hot conditions produce good fishing.
"That's because trout congregate at the cold inflowing streams that flow into Lake Rotorua, places like the Hamurana, Awahou, Waiteti and Ngongotahā stream mouths.
"Some of these streams are spring-fed and run at around 10C or 11C all year round."
A man holding a large brown trout. Photo / Getty Images
He said on deeper lakes such as Tarawera, Okataina, Rotoma and Rotoiti, a cool water layer, known as a thermocline, forms about 15-20 metres deep.
"Trout in these lakes go deep to find the cooler water and this makes them easy to target by anglers with a fish finder and using methods such as jigging and downriggers."
Eastern Region Fish & Game Council chairman Ngahihi Bidois said the warmer lake temperatures usually happened in February and March rather than now, triggering the movement of fish into colder places such as stream mouths and upstream.
Bidois said people going fishing needed to be safe and not to go out of their depth. Fish and Game's rangers would actively be monitoring waterways.
"When going from lake to lake, make sure your boat and trailer are clean so they're not spreading freshwater pests ... but otherwise enjoy fishing, be safe and Happy New Year from Fish and Game."
Rotorua Anglers Association president Pete Otto also agreed fish were coming into the stream mouths for the summer season.
Trout fishing in the Ngongotaha Stream. Photo / Supplied
Last Friday, Niwa reported that a marine heatwave was happening all over New Zealand, with warmer waters being more pleasant for swimming.
Niwa fisheries scientist Darren Parsons said for fishing this meant there would probably be different kinds of fish swimming around our coasts.
"Fish respond over the long term, moving down south to maintain the temperature band that they like to be in.
"The ranges of red snapper and pink maomao are extending further south in response to warming conditions over the last few decades and it will be no different this year."
He said it was not only species common in New Zealand that were on the move - it was also likely there would be more tropical fish, which would be a delight for game fishers and divers alike.
"We'll probably be getting some visitors from the tropics. Tropical species like warm waters, so they'll be travelling further south.
"Water temperatures also impact fishes' metabolism. Their body temperature is the same as the water around them, so when they're warmer, their metabolism speeds up. This means they need to eat more.
"This is great news for fishers - getting a good catch might be a lot easier this year. If the fish are hungry, they're more likely to eat your bait."
He said shark sightings could increase, too.
"If it's nice weather and the waters are pleasant, more people will be out surfing and swimming.
"Just by being out in the water more, we're more likely to see sharks. But sharks head inshore during the summer season anyway; some species follow the warm water to feed and give birth to live young.
"There may be more than usual because it's a marine heatwave, but we can't say for sure. What we do know is that they will be there.
"So, there you have it - enjoy the waters, fish responsibly, and stay safe," Parsons said.
