Gertrude (Lake County)
Florida LAKEWATCH Water Chemistry Summary
Location: Latitude 28°48'48", Longitude 81°39'14"
Period of record: 108 sampling dates; May 8, 1990 to December 29, 1999
Surface area (Shafer et al. 1986): 250 acres / 101 hectacres
Lake Region (Griffith et al. 1997): Mount Dora Ridge
Geologic formation (Brooks 1981):
The geology is dominated by deeply weathered clayey sand and granular sand of the Hawthorne Formation.
Physiographic region (Brooks 1981):
The water body lies in the Central Lakes division of the Central Lake District.
Supplemental, unpublished water chemistry data, University of Florida.
Numbers reported below are the average for 2 months sampled:
|
pH |
7.6 |
Sulfate (mg/L) |
39.7 |
|
Total alkalinity (mg/L as CaCO3) |
31.2 |
Calcium (mg/L) |
14.7 |
|
Conductance (µS/cm @ 25 °C) |
254 |
Magnesium (mg/L) |
8.0 |
|
Color (Pt-Co units) |
5 |
Sodium (mg/L) |
12.7 |
|
Chloride (mg/L) |
27.7 |
Potassium (mg/L) |
9.3 |
|
Silicon (mg/L) |
0.3 |
|
|
Long-term Florida LAKEWATCH Data
Numbers reported below are the minimum, average, and maximum value for the 108 months sampled:
|
|
Minimum |
Average |
Maximum |
|
Long-term total phosphorus concentrations (µg/L) |
3 |
8 |
40 |
|
Long-term total nitrogen concentrations (µg/L) |
320 |
500 |
680 |
|
Long-term total chlorophyll concentrations (µg/L) |
1.0 |
3.0 |
9.3 |
|
Long-term Secchi depth (ft) |
10.0 |
14.4 |
22.5 |
1999 Florida LAKEWATCH Data
Numbers reported below are monthly averages calculated from 3 stations for total phosphorus (TP, µg/L), total nitrogen (TN, µg/L), chlorophyll (CHL, µg/L) and Secchi depth (SECCHI, ft) during 1999:
|
Date |
TP (µg/L) |
TN (µg/L) |
CHL (µg/L) |
SECCHI (ft |
|
Jan-22-99 |
19 |
470 |
2.3 |
14.7 |
|
Feb-28-99 |
40 |
680 |
5.0 |
13.0 |
|
Mar-27-99 |
18 |
460 |
8.0 |
13.2 |
|
Apr-30-99 |
10 |
420 |
2.0 |
11.3 |
|
May-27-99 |
12 |
410 |
3.0 |
11.7 |
|
Jun-14-99 |
7 |
370 |
2.0 |
12.7 |
|
Jul-31-99 |
9 |
410 |
2.7 |
13.3 |
|
Aug-29-99 |
9 |
350 |
3.0 |
14.0 |
|
Sep-10-99 |
8 |
380 |
3.3 |
12.0 |
|
Nov-29-99 |
11 |
570 |
3.7 |
11.8 |
|
Dec-29-99 |
10 |
550 |
9.3 |
13.2 |
|
|
|
|
|
|
|
1999 Average |
14 |
460 |
4.0 |
12.8 |
Gertrude (Lake County)
Florida LAKEWATCH Aquatic Plant Summary
Aquatic plant data collected on June 2, 1992
|
Percent area covered with aquatic vegetation (PAC, %) |
12 |
|
Percent of lake's volume filled with vegetation (PVI, %) |
1 |
|
Average emergent plant biomass (kg wet wt/m2) |
3.4 |
|
Average floating-leaved plant biomass (kg wet wt/m2) |
0.8 |
|
Average submersed plant biomass (kg wet wt/m2) |
8.7 |
|
Average width of emergent and floating-leaved zone (ft.) |
34 |
|
Average lake depth (m) |
6 |
Frequency that plant species occur in 10 evenly spaced transects around the lake.
|
Common Name |
Plant Species |
Frequency (%) |
|
tapegrass |
Vallisneria americana |
80 |
|
maidencane |
Panicum hemitomon |
80 |
|
musk-grass |
Chara spp. |
80 |
|
Illinois pondweed |
Potamogeton illinoensis |
70 |
|
cat-tail |
Typha spp. |
50 |
|
torpedograss |
Panicum repens |
50 |
|
rush fuirena |
Fuirena scirpoidea |
50 |
|
pickerelweed |
Pontederia cordata |
40 |
|
lemon bacopa |
Bacopa caroliniana |
40 |
|
water-pennywort |
Hydrocotyle umbellata |
40 |
|
water primrose |
Ludwigia octovalvis |
40 |
|
sawgrass |
Cladium jamaicense |
40 |
|
spatterdock |
Nuphar luteum |
30 |
|
fragrant water-lily |
Nymphaea odorata |
20 |
|
elephant-ear |
Colocasia esculenta |
20 |
|
buttonbush |
Cephalanthus occidentalis |
20 |
|
duck-potato |
Sagittaria lancifolia |
10 |
|
slender spikerush |
Eleocharis baldwinii |
10 |
|
willow |
Salix spp. |
10 |
|
giant bulrush |
Scirpus californicus |
10 |
|
pipewort |
Eriocaulon spp. |
10 |
|
St. John's wort |
Hypericum spp. |
10 |
|
bladderwort |
Utricularia foliosa |
10 |
|
water hemlock |
Cicuta mexicana |
10 |