Reel Life January 2024
Above Right: Anglers fishing the Taylor River in downtown Blenheim- photo Jacob Lucas
Drift Dive Update
In the past month the Wangapeka, Takaka and Waingaro rivers were dived.
It will be no surprise to anglers that the Wangapeka is still in very good shape, which mirrors feedback from anglers over the past few years.
Staff believe the La Nina period experienced over the past few years has been beneficial for the Wangapeka, which is less impacted by weather coming from the North, and received very few flood events.
Now that we have switched to El Nino, there will be more flood events for this river, though so far this summer these have been characterised by nothing more than healthy ‘top ups’ which have come at a good time over the hot summer when river temperatures have been relatively high.
While the lower Wangapeka site at Walter Peak showed fewer fish in the medium cohort, the number of large fish was still high with 151 larges counted for the 1km dive.
Pleasingly, the upper site at Chummies Creek had one of the best counts on record, with similar numbers of large fish compared to the past two years (48 fish), and a record count of 63 small fish over the 1km dive, something we have not seen for some years.
In total contrast, the two Golden Bay rivers revealed a very poor count, with just 4 large, 4 medium and 4 smalls in the Waingaro, despite great looking habitat; and a similar showing in the Takaka of 3 large, 5 medium and 1 small covering the reach from the Takaka/Waingaro confluence down to Kotinga Bridge.
Next up is the Branch/Leatham, Rai/Pelorus and the Motueka.
Taylor River Family/Whanau Fishing Day
A day to bring the community together and encourage healthy eating was the focus of a family/whanau fishing day on the Taylor River over the weekend.
Nelson Marlborough Fish & Game Councillor, Guy Gardiner, who organised the event, has a vision to foster a healthy outdoor activity that families and children could access without having to travel and make use of a quality trout stream flowing through the middle of town.
Guy says the day was hoped to bring the community together, with fishing as a focus to encourage healthy eating (kai awa) and active families, both of which are core programs of the supporting health providers and included a cook-up of wild venison sausage or crumbed trout fillet and coleslaw sandwiches.
Around 30 enthusiastic anglers attended the event, who were supported by ‘guides’ from Fish & Game and the Marlborough Freshwater Anglers Club. Fishing on the day was challenging, though it wasn’t from lack of trout in the river.
Guy says that plenty of trout were in plain view, though they had a lot of lures thrown at them and became hard to catch.
“Now these new anglers have seen the fish on offer and have been taught new skills on how to catch them, we hope they will return to the Taylor River and other great waterways in the region, and become future anglers”
The event was supported by Nelson Marlborough Fish and Game, Marlborough Primary Health, Te Piki Oranga and Marlborough Hunting and Fishing who generously donated fishing gear, including new rods which participants could take home.
Guy says that the unique situation provided by the Taylor River makes fishing available on foot or cycle after school and at the weekends for our young folk.
“In a nutshell, we want to get families, and especially children, outdoors and active and off their screens and devices.”
“This is just a starting point. We are hoping to run similar events in the future.”
A licence is required to fish for trout, and the Taylor River ‘junior’ fishery regulation has been broadened so parents can now fish there with their children.
When the going gets hot - some 'must read' advice from Tony Entwistle.
Tony Entwistle is a man who knows a lot about trout, and luckily for you, he’s written down some fantastic advice on how temperature affects trout, and what you should be doing to maximise your catch rate over the warm summer months.
Tony has an excellent website, and offers Casting Lessons, Tuition and Mentoring, River Skills and Trout Tactics – all at a very reasonable cost. Check out his Fly Fishing With Tony website here to book some time with Tony.
Here is Tony’s story:
Improving Success When Water Temperatures Climb
The importance of water temperature on trout feeding behaviour can not be understated. Anyone who has attended one of my First Steps classes will also recall, that along with the availability of food, a trout's feeding activity and ability to metabolise that food is significantly controlled by water temperature.
The survival range for a brown trout is from 0°C – 25°C.
- Growth limits for brown trout are from 4°C – 19°C
- Optimum growth range is 7°C – 18°C
- Optimal temperature for maximum growth is 14°C
- Stress temperature range is 19°C – 25°C
- Lethal temperature range is 25°C+
Brown trout feeding behaviour slows down substantially after 18°C and on many rivers, will come to a halt around 21°C.
Through November into early December, water temperatures were cool enough that feeding activity didn't fire up until around 1100 - 1130.
However, from now on you should be looking to hit the water early, to avoid missing the start of the feeding period, which is when the trout are hungriest and the most aggressive.
As they fill their stomachs feeding activity declines as the day progresses.
By early January, as river levels drop and temperatures climb in the hot weather, the best fishing period will be over by 1400 - 1500.
The following graph, collected from over 2000 trout landed in the upper South Island, illustrates the prime fish-catching temperature zone, and how the number of trout caught drops away quickly at temperatures over 18°C.
During a hot summer (like this one), from early January right through until mid-March, you will need to adjust your fishing behaviour to take into account the limiting effects of water temperature.
This will have a huge impact on your success or failure, especially on many of our more accessible local rivers here at the top of the South Island.
On hot, clear days water temperatures on many local rivers will vary in range through as much as 4 - 5°C ... as illustrated by this recent temperature graph of the lower Wairau River.
The Marlborough District Council provides some excellent information on its website, including river flow and temperature data, at hydro.marlborough.govt.nz/environmental.
Note that the coolest temperature each day is around 0700 - 0730.
The maximum temperature shift during the week was 4.8°C and on three days the temperature peaked at over 23°C (the level that triggers a complete shutdown of feeding for brown trout).
For the first five days, the temperature started at a low of around 18.5°C, which is already nudging the stress-temperature range of 19°C – 25°C.
My earlier catch records show that the opportunities to catch fish are almost gone by the time the temperature hits 21°C, which was reached by midday on four out of five of the first five days.
The prime opportunity for catching trout during this week was the four to five-hour window from just after dawn, to midday at the latest.
Those anglers who weren't on the water until mid-morning or after lunch, were probably better to have stayed at home and mowed the lawns.
The two prime days to get excited about getting on the water this week, were the 16th and 17th, when a weather change on the east coast dropped the temperature range back into the 17.3°C - 20°C range.
The Motueka River also experiences very similar temperature profiles. Wouldn't a temperature logger on the Motueka River be a wonderful asset for anglers
Interestingly, Motueka trout seem to have adapted somewhat to slightly higher average water temperatures than on many other rivers.
From experience, I have found the Motueka River to produce a few more fish at slightly warmer temperatures, at times producing fish right through until 22°C.
On the 13th of January, a friend and I arrived on the Motueka River to find that the starting water temperature at 0730 was 20.3°C.
As the sun touched the water a few trout started rising sporadically to an early morning mayfly hatch close to willow cover, and we both landed a couple of nice brownies.
By 1000 the water temperature had moved to 21.5°C and we had stopped seeing rising fish.
We quickly pushed on upstream to an area where a run of fast water flowed through a mix of riffles and deeper slots amongst the bedrock.
We were then pleasantly surprised to get into a group of actively nymphing trout that willingly took our double-nymph rigs (size #16s on 5X tippet).
For about 40 minutes, we had several double hookups and some fabulous fishing before the water temperature hit 23°C at 1130 and the fish promptly shut down.
This does illustrate the need to be in the right place at the right time ... and at this time of year, that means early in the morning!
Not all rivers experience the extremes of the Motueka River and Wairau River, but I have found similar issues on the likes of the Pelorus, Rai, Motupiko, Mangles, Owen, and Buller Rvs (compounded on the Buller by warm water flowing off the surface of both Lakes Rotoiti and Rotoroa).
Further south I have experienced the same on the lower Waiau River in Canterbury and the Opihi River in South Canterbury ... both freestone streams.
Luckily, there are some other ways to mitigate the difficulties of fishing in the extreme heat.
Some rivers have naturally colder temperature profiles. Rivers that start higher in the mountains for instance, such as the upper Wangapeka, upper Wairau, Travers, and Sabine seldom get into the stress-temperature range.
Other Nelson rivers are also fed by cooler artesian water from large underground springs.
Where these tributaries run into a bigger river can be a 'hot spot' for fly-fishing.
Trout will often congregate in these places, where the water temperature can be several degrees cooler for 30 - 100m downstream before it mixes with the warm water of the mainstream.
Natural spring creeks also tend to feature a narrower temperature band each day, with only a 2°C spread.
It is worth noting that rainbow trout can handle temperatures that are 1-2°C warmer than brown trout, which makes them an alternative target when the hot weather hits.
The moral of the story to improve your success during a hot spell, (especially if you don't have a good thermometer to monitor the temperature), is to get out of bed and fish early ... make the effort and you will reap the rewards.
Just a cautionary note when handling trout you intend to release when water temperatures are up over 19°C;
- minimise your contact with the fish
- wet your hands
- keep the trout in the water as much as possible
- where possible, remove the hook and release the trout without lifting it from the water
- if you want a photo, only lift the trout a short distance above the water for just a second or two.
The Team at Nelson Marlborough Fish & Game.