Department of Conservation | Te Papa Atawhai
https://www.doc.govt.nz/
https://www.doc.govt.nz/
Introduction
This is the second in our series of monthly reports where we share details of the trout recorded passing through the Waipa spawning trap.Located on the Waipa Stream, the Waipa spawning trap is positioned within a significant spawning tributary of the Tongariro River, 24 km upstream from Lake Taupo.
Fishery Rangers record the numbers of trout, their sex, length, weight and iteroparity (how many times individual fish have spawned). From this data we also determine a Condition Factor, which reflects how much food has been available to the trout.
This trap has been operational since 1998 and has provided a valuable long-term data set. We view this information in combination with a variety of other studies such as angler surveys, drift dives and lake productivity work, to ensure a broad understanding of fishery's health.
Trap data for June
As the winter season progresses so the number of trout reaching the trap increases. A total of 160 trout were documented this month compared to 60 in May. This trend is likely to continue over the coming months.
Compared to June last year there is a significant improvement in the size and condition of the trout – very good news for anglers. Our graphs and tables show improvements across the board for brown and rainbow trout.
Larger average lengths and weights are good to see. Yet for many anglers, the most significant observation will be the improvement in condition factor (CF). This translates to healthy well-fed fish, that not only provide a challenge to land but are good to eat – important to those who choose to harvest trout.
The increased size and condition of trout passing through the trap echoes reports from anglers, retailers and accommodation providers, who are all in buoyant mood and optimistic for the season ahead.
To see all our data and graphs for June, you can download this month's report sheet (XLSX, 45k). Further information is also available on the May 2019 trap report.
| June 2019 | June 2018 | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Brown trout female | Brown trout male | Rainbow trout female | Rainbow trout male | Total | Total rainfall (mm) | Brown trout female | Brown trout male | Rainbow trout female | Rainbow trout male | Total | Total rainfall (mm) | |
| Count | 54 | 70 | 10 | 26 | 160 | 140.0 | 54 | 88 | 18 | 20 | 180 | 153.5 |
| Average length (mm) | 591 | 614 | 532 | 504 | 578 | 597 | 483 | 490 | ||||
| Max length (mm) | 660 | 720 | 585 | 560 | 660 | 680 | 535 | 555 | ||||
| Average weight (kg) | 2.7 | 2.8 | 1.8 | 1.6 | 2.5 | 2.5 | 1.3 | 1.3 | ||||
| Max weight (kg) | 3.7 | 4.1 | 2.3 | 2.1 | 3.5 | 3.9 | 1.8 | 2.3 | ||||
| Condition factor | 46 | 43 | 43 | 43 | 45 | 42 | 42 | 40 | ||||