Moonshine Lake Reservoir water quality monitoring report : provincial parks lake monitoring program

2006·4.8 MB·English

by  Swanson, Heidi

KL.Z Z007-1^Z
Cl.
Moonshine Lake
Reservoir
Water Quality Monitoring Report
Provincial Parks Lake
Monitoring Program
/dlbcria
Government
Digitized by the Internet Archive
in 2016
https://archive.org/details/moonshinelakeres00swan_0
Moonshine Lake Reservoir Water Quality
Monitoring Report - P rovincial Parks Lake
Monitoring Program
Prepared by:
Heidi Swanson, M.Sc.
&
Ron Zurawell, Ph.D., P.Biol.
Limnologist/Water Quality Specialist
Monitoring and Evaluation Branch
Environmental Assurance Division
Alberta Environment
February, 2006
W0618
ISBN: 0-7785-5301-9 (Printed Edition)
iSBN: 0-7785-5302-7 (On-line Edition)
Web Site: http://www3.gov.ab.ca/env/info/infocentre/publist.cfm
Any comments, questions or suggestions regarding the content of this document may be
directed to:
Environmental Monitoring and Evaluation Branch
Environmental Assurance Division
Alberta Environment
12 th Floor, Oxbridge Place
9820- 106 Street
Edmonton, Alberta T5K 2J6
Fax: (780) 422-8606
Additional copies of this document may be obtained by contacting:
Information Centre
Alberta Environment
Main Floor, Oxbridge Place
9820- 106 Street
Edmonton, Alberta T5K 2J6
Phone: (780) 427-2700
Fax: (780) 422-4086
Email: [email protected]
Preface
Provincial Parks Lake Monitoring Program
The purpose of the Provincial Parks Lake Monitoring Program is to routinely collect
infomiation that describes the cun'ent status of water quality within a suite of recreational
lakes and reservoirs (Appendix I, Table Al). These waterbodies vary considerably in
terms of their physical (e.g. size, shape and mean depth), chemical (e.g. salinity, pH,
alkalinity) and biological (e.g. algae and fish populations) characteristics and represent
the spectrum of water quality found within other typical lakes and reservoirs in Alberta.
The program, which is a collaborative effort between the departments of Environment
and Tourism, Parks, Recreation and Culture, is one of the largest interdepartmental
monitoring efforts in Alberta and a key component of the Provincial Lake Monitoring
Network.
This report is one in a series of nineteen that provide a brief assessment of recent and
historical infonnation collected through the Provincial Parks Lake Monitoring Program in
an attempt to describe current states of water quality in these recreational waters. Many
questions will undoubtedly come to mind as you read this report. A d etailed primer on the
topic of Limnology (lake and river science) and additional resources are provided in
Appendix I t o aid in the interpretation and understanding of these reports.
Reports are available for the following Provincial Parks Lakes:
Beauvais Lake Elkwater Lake McLeod Lake Saskatoon Lake
Cardinal Lake
Miquelon Lake Spruce Coulee Res.
Chain Lake Gregg Lake* Moonshine Lake Steele Lake
Gregoire Lake
Crimson Lake Lake Newell
Sturgeon Lake
Jarvis Lake*
Reesor Lake Res.
Dillberry Lake Long Lake Winagami Lake
* C ompiled in a single report.
Moonshine Lake Reservoir
Moonshine Lake is a small R* •
reservoir located approximately
1 1 0 km north of Grande
Prairie, Alberta in Moonshine
Lake Provincial Park. Prior to
creation of the provincial park,
Moonshine Lake was a small
Provincial Park
wetland that was popular with
local residents as a p icnic spot.
The park was created in 1959.
At this time, a weir and dyke Tp.T#
were installed to raise the water
level and increase the lake
surface area (Figure 1). Today,
the small reservoir is a p opular
destination for camping,
swimming, and fishing for
stocked rainbow trout
LEGEND
w^6tii Met
{Oncorhynchus mykiss).
CROWN LAND
BOAT LAUNCH CAMPGROUND
Moonshine Lake Provincial o
DAY-USE AREA
BEACH
Park completely surrounds the
reservoir. There is significant
Figure 1. Map of Moonshine Lake (Mitchell and
recreational development in the Prepas, 1990).
provincial park but the rest of
the drainage basin is a mixture
of forest and wetlands; there is no residential or agricultural development. White spruce,
trembling aspen, and balsam poplar are common in forested areas while black spruce.
Labrador tea. Sphagnum and feathermoss are common in wetlands.
Physical Characteristics
Table 1. Physical characteristics
Although a full bathymetric survey has not
Moonshine Lake Reservoir.
been conducted on Moonshine Lake of
Elevation (m) full supply 718.11
0.28
there was no defined inflow to the lake Surface area (km^)
0.37
(Figure 1). This ditch provides water during MEsatxiimmautemd dVeopltuhm e ( m )( million m^)
3.5
1.3
snowmelt and heavy rainfall events. Water
Estimated Mean depth (m)
can be released at the dam on the east side
of the reservoir and there is an overflow 6.84
Drainage basin area (km^)
ditch on the southwest shore (Figure 1). Water releases are rare, however.
1
Water Levels
Elevation has been monitored in Moonshine Lake since 1978 and values recorded since
1982 are presented in Figure 2. Water levels were low in 1982-1983 but increased in
1984 and were stable until 2003, when the lake was drawn down to facilitate rebuilding
of the weir (Figure 2).
719.00
718.75
0
0> 718.50
00
C0O 718.25 'tn
>
o
<
0
718.00
0
E
c
g
0 717.75
>
Lll
0
717.50
0
_I
717.25
Year
Figure 2. Historic water ieveis for Moonshine Lake Reservoir, Moonshine Lake
Provincial Park.
Water Quality
Since 1983 (excepting 2000 and 2001), water samples have been collected for water
quality analyses approximately once per month during the open-water season (May
through September). Samples were collected from the euphotic zone (i.e. from the lake’s
surface down to the maximum depth sunlight is able to penetrate to) at ten locations
throughout the lake basin and combined to form one composite sample. These samples
were typically analyzed for total phosphorus and chlorophyll-<7 concentrations and
subsamples analyzed for ion concentrations, alkalinity and hardness. Secchi depth, an
estimate of water clarity and algal biomass, was measured during all sampling events.
Occasionally, summer and winter depth profiles for both temperature and dissolved
oxygen (DO) concentrations were produced by recording measurements at the surface
and 1-m depth intervals to the lake bottom (See Appendix II for data).
2
Water Temperature and Dissolved Oxygen
Temperature and DO depth profile data indicate that Moonshine Lake is usually mixed
during the open-water season (e.g. Figure 3a). This means that temperature and DO
concentrations are generally uniform throughout the water column. There may be weak
stratification on calm, warm days but this is only temporary. Summer stratification results
in decreasing temperature and DO concentrations with increasing depth. There is some
degree of winter stratification in Moonshine Lake, but the temperature gradient from
surface to bottom is often only 1-2°C (Figure 3b). Winter stratification patterns usually
involve water temperatures rising from 0°C at the surface (immediately below the ice) to
4°C at the bottom with a concurrent decrease in DO concentrations (Figure 3b). This
occurs because water is most dense at 4°C. Illustrations of all available temperature and
dissolved oxygen profiles are presented in Appendix II.
The Alberta surface water quality guidelines for DO are 5.0 mg/L for instantaneous
conditions, and 6.5 mg/L for longer-term conditions (calculated as a 7-day mean). For
periods when early-life stages of fishes develop, the guideline is 9.5 mg/L. Because
Moonshine Lake is typically mixed in summer, DO concentrations are usually above
instantaneous and chronic guidelines throughout the water column. There was one
summerkill event in 1977, however. Summerkill occurs when DO concentrations are not
high enough to support fish and a fish die-off occurs (see Appendix I for details).
Winterkill has also occurred in the past and repeated events led to the installation of an
aeration system in October 1983. Since the introduction of aeration, concentrations in
winter have frequently fallen below instantaneous and chronic guidelines, but winterkill
has been prevented. Concentrations of dissolved oxygen have frequently been less than
the early life stage guideline (9.5 mg/L), but this is common in Alberta lakes.
Water Temperature (oC) Water Temperature (oC)
6 8 10 12 14 16 18 20 0 1 2 3 4 5 6
o
d
— ^ DO
...o... Temp
1
a
August 13, 2003
6 8 10 12 14 16 18 20
Dissolved Oxygen (mg/L) Dissolved Oxygen (mg/L)
Figure 3. Summer mixing (a) and weak winter
stratification (b) in Moonshine Lake Reservoir.
3
Trophic State and Water Clarity'
Total phosphorus (TP) and chlorophy 11-^7 (Chl-c/) concentrations are indicators of trophic
state (level of fertility) in freshwater lakes and reservoirs. Phosphorus is a limiting
nutrient for algal populations in most fresh waters and Chl-^/ is a d irect estimate of algal
biomass. Trophic state varies from oligotrophic (low TP and Chl-c/, clear water) to
hypereutrophic (very high TP and C\\\-a, murky water). Most lakes in Alberta have
naturally high nutrient and resulting Chl-<7 concentrations, but industrial, agricultural, and
urban development can increase these concentrations above background levels,
negatively impacting water quality (See Appendix 1 f or more details).
Oligotrophic
(Low Productivity)
(<2.5 pg/L)
Mesotrophic
O)
D. (Moderate Productivity)
(2.5-8 pg/L)
<Cv
o
Eutrophic
c 60 (High Productivity)
(8-25 pg/L)
oc •c
o
o
Hypereutrophic
(Very High Productivity)
(>25 pg/L)
sz
>s
CL
o
o
_o
rn m n
I I
E
5 O
z
0)
Figure 4a (top) and 4b (bottom). Trophic state of Alberta lakes in the Provincial Parks
Monitoring Program based on mean total phosphorus and chlorophyll-a concentrations,
May to October, 1982-2004.
4
Mean TP (146 mg/L) and Chl-a (22.67 mg/L) concentrations indicate that Moonshine
Lake is currently eutrophic/hypereutrophic (Figures 4a and 4b; Table 2). The number of
algae (indicated by C\A-a concentrations) is low relative to the amount of phosphorus in
the lake, but algal blooms are common and the lake does turn green in summer.
Seasonal patterns of Chl-a and TP concentrations in Moonshine Lake Res have varied
among years. The most common pattern is a gradual increase in TP and Ch\-a
concentrations, beginning in spring. Chlorophyll-a usually peaks in July and TP usually
in August. In some years, the pattern is reversed with maximum TP concentrations
occuring approximately one month before Chl-a. Concentrations of TP have increased in
Moonshine Lake from 1983-1994 and have since decreased (Figure 5). Concentrations of
Ch\-a have been variable, but appear to have loosely reflected the pattern in TP (Figure
5). Water clarity as measured by Secchi depth generally follows (inversely) that of TP
and Ch\-a concentrations (Figure 5).
CN CN C\J CN CSJ
Year
Figure 5. Mean summer (May - October) chlorophyil-a concentrations, total
phosphorus concentrations and Secchi depth from 1983-2004.
5