NORBURY AND KlKOMUN CREEKS KOKANEE ...a100.gov.bc.ca/appsdata/acat/documents/r39555/Norbury...Sixty kokanee (30 males and 30 females) were collected from both Norbury and Kikomun creeks.

NORBURY AND KlKOMUN CREEKS (UPPER KOOTENAY RIVER BASIN)

KOKANEE SPAWNING SURVEY 1998

prepared by:

Dan Wigle for:

KtunaxaiKinbasket Development Corporation February 1999

submitted to:

Columbia Basin Fish and Wildlife Compensation Program 103 - 333 Victoria St. Nelson, B.C.

VIL4K3

funded by:

Columbia Basin Trust PO Box 220 Nakusp, B.C.

VOGIRO

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NORBURY AND KIKOMUN CREEKS SPAWNING SURVEY

INTRODUCTION

Kokanee spawning surveys were conducted in the upper Kootenay River basin during the fall of 1996 and 1997 when an estimated 439,000 and 129,600 kokanee were enumerated respectively (Westover 1997 and 1998). In fiscal year 1998/99, the Columbia Basin Trust (CBT) provided funding to conduct the third year of this survey. The terms of reference for this portion of the project were to determine peak of spawning, length and weight by sex, fecundity and post spawning egg retention for kokanee in Norbury and Kikomun creeks.

METHODS

In order to determine peak of spawning, kokanee were enumerated in Norbury Creek between the Kootenay River and the CPR railway culvert. Kokanee were counted by a two person crew, once a week for five weeks, beginning on September 12, 1998. For the purposes of kokanee spawner enumeration the stream was divided into two reaches. One reach extended from the Kootenay River upstream to the pool at the downstream end of the CPR culvert and the second reach was the large pool formed by the CPR culvert outfall. Each person independently recorded the number of kokanee present on two separate passes (one downstream and one upstream) and a mean was calculated for the four counts.

Sixty kokanee (30 males and 30 females) were collected from both Norbury and Kikomun creeks. The fish were dip netted from below partial culvert barriers located on both streams. All captured fish were anaesthetized using clove oil and were subsequently weighed (g) using a Sartorius portable electronic scale and measured for fork length (mm) using a measuring board (photos 1 and 2). Ten females from each stream were sacrificed in order to determine fecundity. Eggs were counted individually to obtain a total egg count for each female. After the peak of spawning, twenty-five female carcasses were collected from both Norbury and Kikomun creeks in order to determine length (mm), weight (g) and post spawning egg retention.

On September 20, 1998 staff from Montana Department of Fish, Wildlife and Parks (MDFWP) collected a number of kokanee from Lake Koocanusa as part of their standard fall gill netting program. Length and weight by sex for these kokanee are presented in this report and compared to kokanee collected from Norbury and Kikomun creeks.

RESULTS

Stream bank counts of kokanee in Norbury creeks are shown in Table 1. Spawning peaked around September 26, 1998 when 7,834 kokanee were estimated to be in Norbury Creek downstream of the CPR culvert.

FIGURE (1) - Weights - recording weights (g)

FIGURE (2) - Measures - recording lengths (mm)

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Table 1. Ground counts of kokanee in Norbury Creek between the Kootenay River and the CPR culvert for the days indicated (1998). II

Date of Survey Estima~ Number of Kokanee

September 12 September 19 September 26 October 3 October 10

2,800 3,870 7,834 3,576 2,692

Length and weight by sex for kokanee from Norbury and Kikomun creeks are shown in Appendix I and are summarized in Table 2 along with dat~ provided by :MDFWP for kokanee collected from Lake Koocanusa on September 20, 1998. Length and weight of kokanee varied

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by sampling location, with the kokanee collected from Norbury Creek having an overall smaller fork length (Table 2). . !

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Table 2. Mean length (mm) and weight (g) of male and ~emale kokanee from Norbury and Kikomun creeks compared to lengths and weights of kokanee collected from Lake Koocanusa by MDFWP.

System

Norbury Creek* Kikomun Creek* Lake Koocanusa**

315.4 336.2 337.9

Males

365.4 321.6 I

429.7 339.1 360.8 332.4

* n = 30 males and 30 females from each stream.

Females Mean Wei ht

341.8 387.2 327.4

** n = 45 males and 60 females. Data provided by Neil Benson of MDFWP (pers. comm.)

i Fecundity for the kokanee collected from Norbury and Kikomun creeks are shown in Table 3.

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Female kokanee from Norbury Creek were smaller than females from Kikomun Creek with an average fork length of 317 nun and 335.5 mm respectively. I Note that the average length of these kokanee were somewhat different than the average length of the 30 females shown in Appendix I. Kokanee from Norbury Creek were also less fecund withl an average of 695 eggs compared to 764 eggs per female from Kikomun Creek. :

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Table 3. Length (mm), weight (g) and fecundity for kokanee collected from Norbury and Kikomun creeks, September 16 and 17, 1998.

Kikomun Creek Len h(mm) Fecundi Wei ht Fecundit

321 332.4 953 329 331.4 776 319 362.6 645 340 418.9 813 326 350.7 928 325 338.5 762 337 390.3 373 339 378.2 942 337 376.6 639 331 377.1 830 311 326.5 974 332 358.3 430 333 360.5 620 345: 433.9 827 249 160.1 323 329 318.1 693 317 338.7 908 359 489.5 783 320 344.1 584 326 379.8 788

Mean = 317 334.2 694.7 335.5 382.4 764.4

The average post spawning egg retention was almost identical for female kokanee from Norbury I

and Kikomun creeks (20.4 eggs and 20.3 eggs respectively). The number of eggs retained ranged from 0 to 124 in Norbury Creek and from 0 to 239 in Kikomun Creek (Table 4).

DISCUSSION

Kokanee spawning in Norbury Creek appeared to peak around September 26, 1998 approximately one week earlier than in 1997. Both the CPR culvert on Norbury Creek and the Highway culvert under the Jaffrey/Baynes Lake road appear to be partial barriers to spawning kokanee (Photos 3 and 4). Spawning kokanee for this study were collected at the downstream end of these culverts and may explain some of the difference between the lengths of these fish between systems. Perhaps only the larger kokanee were successful in passing through the CPR culvert on Norbury Creek and consequently only the smaller fish were sampled.

Although every attempt was made to collect green kokanee to determine fecundity, it became apparent that some of the kokanee were ripe and may have lost a portion of their eggs prior to being collected.

RECOMMENDATIONS

Mean length of kokanee and the total spawning population varies considerably from year to year on Lake Koocanusa (Westover, 1997 and 1998). It is recommended that this project continue for the next 3 years in order to determine the fecundity of spawning kokanee at different lengths. This information will assists in managing this fishery.