Status report on the water quality of Lake Ozette and potential human-related impacts on salmonids

88 Pages·2001·4.1 MB·English

by  Meyer, J., Brenkman, S.

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Status Report on the Water Quality
of Lake Ozette and Potential
Human-related Impacts on Salmonids
November 2001
John Meyer
and
Sam Brenkman
Olympic National Park
600 E. Park Ave
WA
Port Angeles, 98362
NATIONAL PARK SERVICE
Wa&trResources Division
FortOiling, Colorado
Resource Room Property

Status Report on the Water Quality of Lake Ozette and
Potential Human-related Impacts on Salmonids
November 2001
John Meyer
and
Sum Brenkman
Olympic National Park
600 East Park Ave.
Port Angeles, Washington 98362
Digitized by the Internet Archive
in 2012 with funding from
LYRASIS Members and Sloan Foundation
http://archive.org/details/statusreportonwaOOmeye
681
TABLE OF CONTENTS
Page
LIST OF FIGURES, TABLES, AND APPENDICES 2
ABSTRACT
5
INTRODUCTION 6
STUDY AREA 6
METHODS
8
Water Quality Monitoring 8
Water Chemistry andNutrients 9
Chlorophyll 9
Zooplankton 10
Fish Observations and Sampling 10
Vegetation Monitoring 1
RESULTS 12
Lake Ozette
Water Temperature and Dissolved Oxygen 12
pH 12
Specific Conductance 13
Turbidity 13
Water Chemistry and Nutrients 14
Chlorophyll 14
Zooplankton 14
Observations ofLakeshore Sockeye Spawners 15
Vegetation Monitoring 15
Tributaries to Lake Ozette
Water Temperature
1
Dissolved Oxygen 16
pH 16
Specific Conductance 16
Turbidity 17
Fish Species Composition 17
DISCUSSION
Limnological Conditions in Lake Ozette 17
WaterQualityConditions inthe Ozette Riverand Tributariesto LakeOzette 1
Potential Factors in the Decline ofOzette Sockeye 20
ACKNOWLEDGMENTS 24
LITERATURE CITED 25
LIST OF FIGURES, TABLES, AND APPENDICES
Figures:
1. Area map ofLake Ozette.
2. Depth contours (m) for Lake Ozette.
3. Location ofwater quality sampling stations (1 to4) and vegetation transects (A to G) on Lake Ozette during
1993 and 1994.
4. Mean seasonal temperatures ofLake Ozette from the surface to 67m at water quality sampling Station 4, 1993-
94.
5. Monthly watertemperature and dissolved oxygen profiles for Lake Ozette at Station 4, 1993-94.
6. Seasonal pH profiles for Lake Ozette at Station 4, 1993-94.
7. Seasonal profiles ofconductivity for Lake Ozette at Station 4, 1993-94.
8. Turbidity plume on the surface ofLake Ozette on March 3, 1994.
9. Daily maximum and minimum watertemperatures in the Lake Ozette tributaries, 1994. The thermograph
probe in Big Riverwas exposed to air sometime before August 25 and no reliable data were collected at this
site priorto that date.
10. Comparison ofseasonal water quality measurements collected atthe bottom (30m) ofLake Ozette at sampling
Station 1, 1976 (Bortleson and Dion, 1979) and 1994.
1 1. Average seasonal depth ofSecchi disk readings for four sampling stations in Lake Ozette, 1976 (Bortleson and
Dion, 1979) and 1994.
12. Comparison ofseasonal nitrate and nitrite concentrations in water samples collected at 18 m from four
sampling Stations in Lake Ozette, 1976 (Bortleson and Dion, 1979) and 1994 (mean offour stations)
13. Historic trends and fluctuations in estimated run size and reported catch ofQuinault and Ozette sockeye,
respectively, 1910-1973.
14. Comparison ofmean monthly surface elevation ofLake Ozette from 1981-99 (lake level readings were not
consistently recorded in 1995-97) and mean surface elevation during two wet years (1990-91 and 1998-99
water years) when the lake rose during the sockeye spawning period but dropped priorto emergence ofthe
alevins from the gravel.
Tables:
1. List offish species present in the Lake Ozette Basin, Washington. •
2. Gill net catches and sockeye escapement estimates from the Ozette River. Gill net catches landed by the
Makah Tribe. Sockeye escapement estimated from weir counts by the US Fish and Wildlife Service and the
Makah Tribe.
3. Range ofwater quality variables collected at Lake Ozette sampling Station 1 at lm and on the bottom
(approximately 27 m), December 1993 - October 1994.
4. Range ofwater quality variables collected at Lake Ozette sampling Station 2 at lm and at 74 m, December
1993 -October 1994.
5. Range ofwater quality variables collected at Lake Ozette sampling Station 3 at lm and on the bottom
(approximately 70 m), December 1993 -October 1994.
6. Range ofwater quality variables collected at Lake Ozette sampling Station 4 at lm and at 74 m, December
1993 -October 1994.
7. Mean Secchi disk readings (m) at Lake Ozette Stations 1-4, September 1993-October 1994.
8. Concentrations ofnutrients in water samples collected from Lake Ozette, August 29-30, 1993. Samples
collected from the surface, 18 m, and nearthe bottom in mg/L. Dissolved P04-P values equal to 0.001 were
below the detection level ofthe lab instruments.
9. Concentrations ofnutrients in watersamples collected from Lake Ozette, January 18, 1994. Samples collected
from the surface, 18 m, and nearthe bottom in mg/L. Dissolved P04-P values equal to 0.001 were below the
detection level ofthe lab instruments.
10. Concentrations ofnutrients in water samples collected from Lake Ozette, May 23, 1994. Samples collected
from the surface, 18 m, and nearthe bottom in mg/L. Dissolved P04-P values equal to 0.001 were below the
detection level ofthe lab instruments.
.
1 1. Concentrations ofnutrients in water samples collected from Lake Ozette, July 18, 1994. Samples collected
from the surface, 18 m, and nearthe bottom in mg/L. Dissolved PO„-P values equal to 0.001 were below the
12.
13. detection level ofthe lab instruments.
14. Chemical composition in mg/L ofwater samples collected from Lake Ozette Stations 1 -4 on August 29 -30,
1993.
15. Chemical composition in mg/L ofwater samples collected from Lake Ozette stations 1 -4 on January 18
1994.
16. Chemical composition in mg/L ofwater samples collected from Lake Ozette Stations 1 -4 on May 23, 1994.
17. Chemical composition in mg/L ofwater samples collected from Lake Ozette Stations 1 -4 on July 18, 1994.
18. Concentrations ofchlorophyll at 0-20 m collected from Lake Ozette sampling Stations 1,2, and 4, 1994.
19. Mean monthly densities (number/m3) ofzooplankton taxa in 0-30 and 0-5 m vertical tows, Lake Ozette, 1994.
20. Planttaxa identified in vegetation plots at Lake Ozette.
21 Range ofvalues forwaterqualityvariables collected in the tributaries and outlet to Lake Ozette, 1993-94. Only
includes data collected between December 1993 -November 1994 with the Hydrolab multi-parameterprobe.
Discharges are notrepresentative ofpeak flows as itwas notpossibletowadethese streams athigh flows,
especially in Crooked Creek and Bigand Ozette Rivers.
22. Monthlywaterquality values forthe Ozette River, 1993-94. Datacollected on January 5, 1994 andpriorto
December 15, 1993 measured with various hand held instruments; all other information measuredwith a
Hydrolab multi-parameter instrument. Measurements made on December 11, 1993, March2, andNovember30,
1994 collected during storm events.
23. Monthly waterquality values forCoal Creek, 1993-94. All data collected with aHydrolabmulti-parameter
instrument. Measurements made on March2 andNovember30, 1994 collected during storm events.
24. Monthlywaterquality values forUmbrella Creek, 1993-94. Datacollected on January 5, 1994 and priorto
December 15, 1993 measured with various hand held instruments; all other information measured with a
Hydrolab multi-parameter instrument. Measurements made on December 1 1, 1993, March 2, andNovember30,
1994 collected during storm events.
25. Waterquality values for Big River, 1993-94. Data collected on January 5, 1994 and priorto December 15, 1993
measured with hand held instruments; all other information measured with aHydrolab multi-parameter
instrument. Measurements made on December 11, 1993, March 2, andNovember30, 1994 collected during
storm events.
26. Monthly waterquality values forCrooked Creek, 1993-94. Datacollected on January 5, 1994 andpriorto
December 15, 1993 measured with varioushand held instruments; all other information measuredwith a
Hydrolab multi-parameter instrument. Measurements made on December 11, 1993, March 2, andNovember30,
1994 collected during storm events.
27. Monthlywaterquality values forSiwash Creek, 1993-94 Data collected on January 5, 1994 and priorto
December 15, 1993 measured with various hand held instruments; all other information measured with a
Hydrolabmulti-parameter instrument. Measurements made on December 11, 1993 and March2, 1994 collected
during storm events.
28. Monthlywaterquality values forSouth Creek, 1993-94. Data collected on January 5, 1994 andpriorto
December 15, 1993 measured with varioushand held instruments; all other information measuredwith a
Hydrolab multi-parameter instrument. Measurements made on March 2, 1994 collected during a storm event.
29. Fish captured by electrofishing in fourreaches ofSiwash Creek, July 25, 1994.
30. Fish captured by electrofishing in fourreaches ofBig River, July 26, 1994. Reach 1 isthe farthest
downstream.
31. Annual total precipitation, minimum, maximum, range, and mean monthly lake levels recorded at
the Lake Ozette Ranger Station, 1981-94 and 1998-99.
32. Stand age, road density and road crossings in the Ozette watershed.
Appendices
Appendix A: Calibration Procedures forthe Hydrolab Datasonde 3.
Appendix B: Lake Ozette Vegetation Transect and Plot Descriptions.
Appendix C: Lake Ozette Vegetation Plot Results.
Appendix D: Temperature Data from Lake Ozette Tributaries.

ABSTRACT
Physical, biological, and chemical characteristics ofLake Ozette and water quality in six tributaries to the lake were
described from September 1993 to October 1994. The annual range ofwater quality conditions were measured for
watertemperature, specific conductance, turbidity, and pH at four locations on the lake, six tributary streams, and at
the lake outlet. Water quality conditions in the lake generally appeared to be favorable to salmonids although
condition were less favorable in tributary streams. The lake exhibited thermal stratification throughout the summer
months and circulated freely from December to March at watertemperatures ofless than 9°C. Dissolved oxygen in
the lake ranged from 8.6 to 12.4 mg/L throughout the year, and pH values (ranged from 6.7 to 7.7) were consistent
with those observed in other lakes. Specific conductivity was relatively low and uniform throughoutthe water
column (ranged from 33.7 to 43.2 uS/cm). Turbidity varied greatly by sample station, date, and depth. During
routine sampling, surface waters exhibited turbidity levels from 1.4 to 18.0 NTU's but elevated turbidity as high as
35 NTU's occurred after a storm event. From December 1993 to October 1994, mean secchi disk readings ranged
from 3.7 to 6.5 m in depth. There were no consistent changes in concentration ofKjeldhal-N, total dissolved
phosphorus, orthophosphate-P, and ammonia-N with increased depth duringthe sampling period. The zooplankton
community was comprised ofnine crustacean and 15 rotifertaxa. Density ofcladoceran taxawas generally highest
in May and July, and rotifertaxa that were present throughout the sampling season were at maximum densities in
July based on vertical net tows. Chlorophyll varied with waterdepth and time, and results clearly indicate that most
chlorophyll was located in the upperportion ofthe water column in the lake. Water chemistry, nutrients, and
zooplankton densities were within the ranges reported for other lakes with sockeye in Washington, Alaska, and
British Columbia. A cursory inventoiy oflakeshore vegetation identified 24 plant taxa in transects distributed
around the perimeter ofLake Ozette. Water quality conditions in tributaries to Lake Ozette exceeded Washington
State maximum temperature standards forClass AA waters (16.3°C as required by the Forest Practices Act) in four
ofthe lake's tributaries. Maximum daily watertemperatures in the Ozette River exceeded the preferred temperature
range (7.2 to 15.6°C) for migratory adult sockeye salmon in July and August. Elevated turbidity levels were
observed in Big River (185 NTU) and Umbrella Creek (161 NTU) during storm events. Poorwaterquality
conditions in tributaries to the lake's eastern shoreline are believed to have contributed to the decline ofsockeye
salmon in the Ozette basin. Degraded waterquality in these streams appears to have resulted from extensive timber
harvest in the watershed, which began early in this century and accelerated in the 1970's.
INTRODUCTION
Lake Ozette is a 2,954 hacoastal lake located in the northwest cornerofWashington State (Figure 1). The lake lies
entirely within OlympicNational Park (ONP) although most ofthe watershed is located on private forest lands. The
lake and itstributaries support anadromous and resident populations offish but returns ofPacific salmon tothe Lake
Ozette basin have declined since the 1950's (WDFW et al. 1993). The decline ofOzette salmon, and especially
sockeye, have led to several assessments ofadult returns,juvenile production and habitat conditions within the
watershed. In 1976-77, Bortleson and Dion (1979) investigated the waterquality ofthe lake and its tributaries relative
totheirabilityto support salmonids. While they found generally suitable habitatconditions, theirassessment occurred
priortothe period ofpeak timberharvest in the basin. Timberharvest and road building activities that have occurred
since Bortleson and Dion's (1979) studymay haveresulted in negative impacts on waterqualityconditions. These
impacts have likely influenced productivity ofsalmon.
In addition to the decline ofthe lake's fish populations, Olympic National Park staffwas concerned about alterationsto
natural processes in the watershed includingthe invasion ofnon-native plants, changes in the waterquality ofthe lake
and its tributaries, and a suspected increase in sedimenttransport from the tributaries tothe lake. In the mid-1980's,
park stafffrequently noted high turbidity levels in the lake's tributaries and alongthe eastern shoreline during period of
heavy rain fall. Turbidity levelswere reported to be high duringthese periods ofhigh rainfall and were often associated
with logtruck hauling on the extensive network ofgravel roads in the basin outside ofthe park.
The United States Congress acknowledged the existence ofthreatsto the health ofthe Lake Ozette ecosystem in the
Washington Parks Wilderness Act of 1988. Congress directed theNational Park Service to "conduct a study ofthe
watershed ofLake Ozette" and "considerthe various alternativesto protect this area." This study respondstothe
congressional directive by documenting waterquality conditions in the watershed and assessingpotential impacts to
fish resources. Specifically, the objectives ofthis study were to: 1) determine waterquality conditions in Lake
Ozette and its tributaries; 2) provide baseline data for future water quality studies that occur in the basin; and 3)
identify potential factors in the decline ofsalmonids in the Ozette basin.
STUDY AREA
Lake Ozette is the largest lake in OlympicNational Park and thethird largest natural lake in the State ofWashington.
Whilethe lake is relatively large, its drainage basin is small at 199 km2. Lake Ozette lies approximately 9 m above sea
level, has a maximum depth of98 m (Figure 2), and the highest elevation in the drainage is 580 m. The Ozette River