Waipa trap reports – 2022 winter season
Introduction
Read reports of the Waipa Stream fish trap over winter 2022.September 2022
Only a single flood event occurred this month, which halted trap operations for 2 days. This was far less intrusive than flood interruptions seen over the last 3 months.
The rainfall this month (287mm) was still very high compared to monthly measurement in previous years. This exceeded any single monthly rainfall recorded during trap operations in 2021 and 2022.
There were 276 fish recorded in the upstream pen of the trap, all which were rainbows – 153 hens and 123 jacks. Numbers this year are positive and compare well with figures recorded for the same period over the last 5 years. Trout size and condition has fallen from the excellent figures we saw earlier this winter but remain good for the time of year.
Brown trout have largely completed spawning at this time of year so their absence from the upstream trap data is not unexpected.
Much trap management time in September focusses on the downstream pen of the trap, monitoring spent fish as they leave the spawning tributary. This is important information as it allows us to determine the proportion of fish that evaded upstream capture during floods. We then adjust the overall count.
In alignment with data, anglers have been catching a mixture of fresh-run and spent trout. As the days get longer and the weather warms, fewer fresh fish will enter rivers increasing the proportion of recovering trout.
Graphs and tables September 2022 (XLXS, 65K)
August 2022
High rainfall has been a reoccurring theme this year and August was no exception (338.5mm). Two large flood events put the trap out of action for 7 days, so a significant number of fish will have evaded upstream capture.
Despite the downtime we still recorded 260 trout through the upstream pen, 248 of which were rainbows and 12 browns. This is significantly greater than the numbers recorded in August over recent years, and underlines why anglers have been catching plenty of fish this season.
Trout size and condition has dropped slightly compared to previous months but continues to be very good. We know from data gathered over previous years that early spawning trout tend to be the largest, so this reduction is to be expected.
Trap operations remain viable through to the end of November, as fresh trout continue to migrate upstream to spawn. Therefore, anglers can still expect to encounter maiden trout, although we expect numbers will start to drop.
Graphs and tables August 2022 (XLXS, 66K)
July 2022
The trap experienced four flood events during July, with total rainfall measured at 456.5mm. This is an exceptionally high rainfall measurement, underlining just how much rain has fallen recently. While flood conditions restrict trap operation, they certainly don’t restrict trout from migrating upstream.
Those fish that avoided capture due to water breaching the top of the trap will be identified in the downstream pen of the trap, as they head back to Lake Taupo after spawning.
As we would expect at this time of year the number of rainbow trout entering the upstream pen of the trap now far exceeds browns (166 and 61 respectively). Brown trout spawn earlier than rainbows, so their numbers are reducing, while the rainbow migrations are now reaching a peak.
Average fish size and condition continues to be impressive this year and aligns with survey data and reports from anglers.
Graphs and tables July 2022 (XLXS, 66K)
June 2022
Significant rainfall generated good flow rates in the Waipa Stream (353.5 mm), which resulted in a continuation of the high trout numbers witnessed in May.
Average weights for all categories were slightly lower than the exceptional figures recorded last month but remain very good. Condition Factors (CF) are consistently high and on a par with May.
The biggest fish was a Brown Male (BM) of 730 mm, 5.4 kgs and a CF 50.1. A fin-clip scar revealed this fish had previously spawned in 2020.
Other notable trout included a six-year-old Rainbow Male (RM) of 655 mm, 3.55 kgs and a CF 46.7. This fish had previously spawned in 2019, so it was in good condition for a rainbow trout of this age.
This month’s figures make a striking contrast to the same time last year, where low rainfall had negatively impacted flow rates in spawning tributaries and restricted trout from migrating.
Anglers confirm winter 2022 has delivered exceptional trout fishing, marked by both the quantity and quality of the trout – their experience is entirely consistent with the trap data.
Graphs and tables June 2022 (XLXS, 66K)
May 2022
The fish trap was recommissioned in May following an upgrade over summer, and initial data collection got underway. Flow rates in the Waipa Stream have been ideal and encouraged trout to enter this important spawning tributary for the Tongariro River.
The number and quality of fish recorded this May was exceptional, with figures exceeding everything recorded in May 2021. It appears that trout have begun to migrate early this year with 153 fish recorded compared to only 35 last year. The average weight for rainbows (1.9 kgs) is well above normal and the condition of these fish is excellent.
These figures reinforce what we are hearing from anglers, who say the fishing has been excellent.
This winter is shaping up to be something special, so grab your gear and make the most of this great wild trout fishery.