Waipa spawning trap

Image: James Barnett | DOC


A series of monthly reports sharing information gathered from the Waipa Stream fish 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.

Date:  27 November 2019

Below are links to monthly reports from the Waipa trap. These are presented as graphs and tables for each month, with the previous month and same month of last year included. 

Each file includes the below data for brown and rainbow trout (male and female):

  • count
  • average length
  • maximum length
  • average weight
  • maxium weight
  • condition factor.

Reports from 2020 winter season

May 2020

Due to COVID-19 restrictions the spawning trap was not reinstated until the middle of the month which significantly reduced opportunities for data collection.

Therefore, it is no surprise to see fish numbers down on the previous year as this has reduced our sample size.

Lengths and weights are within the expected range, with a visible improvement in the Condition Factor (CF) for Rainbow males (RM).

Limited sampling opportunities combined with low headwater rainfall this year (80 mm May 2020, compared to 230 mm May 2019) may have impacted the results.

Looking ahead, it will be interesting to see how the excellent fishing experienced by anglers in the lower river translates into data collected from this headwater location.

Graphs and tables May 2020 (XLXS, 67K)

Reports from 2019 winter season

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