Joanna (Lake County)
Florida LAKEWATCH Water Chemistry Summary
Location: Latitude 28°50'21", Longitude 81°38'31"
Period of record: 69 sampling dates; January 24, 1990 to November 29, 1999
Surface area (Shafer et al. 1986): 302 acres / 122 hectacres
Lake Region (Griffith et al. 1997): Mount Dora Ridge
Geologic formation (Brooks 1981):
The geology is dominated by quartz sand and quartzite gravel with sandy clay beds of the Hawthorne Formation.
Physiographic region (Brooks 1981):
The water body lies in the Mount Dora Ridge subdivision of the Apopka Upland division of the Central Lake District.
Long-term Florida LAKEWATCH Data
Numbers reported below are the minimum, average, and maximum value for the 69 months sampled:
|
|
Minimum |
Average |
Maximum |
|
Long-term total phosphorus concentrations (µg/L) |
3 |
7 |
24 |
|
Long-term total nitrogen concentrations (µg/L) |
320 |
470 |
650 |
|
Long-term total chlorophyll concentrations (µg/L) |
1.0 |
2.4 |
21.7 |
|
Long-term Secchi depth (ft) |
9.5 |
14.0 |
24.5 |
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-08-99 |
4 |
600 |
2.3 |
14.5 |
|
Feb-11-99 |
6 |
560 |
2.0 |
14.8 |
|
Mar-13-99 |
8 |
560 |
1.3 |
13.0 |
|
Apr-21-99 |
11 |
560 |
2.0 |
13.2 |
|
Jun-03-99 |
9 |
530 |
3.0 |
11.8 |
|
Jul-08-99 |
10 |
540 |
3.0 |
13.0 |
|
Aug-14-99 |
8 |
550 |
3.0 |
12.0 |
|
Sep-22-99 |
6 |
470 |
2.7 |
12.2 |
|
Oct-29-99 |
7 |
530 |
3.0 |
12.5 |
|
Nov-29-99 |
9 |
490 |
3.3 |
12.8 |
|
|
|
|
|
|
|
1999 Average |
8 |
540 |
2.6 |
13.0 |
Joanna (Lake County)
Florida LAKEWATCH Aquatic Plant Summary
Aquatic plant data collected on July 7, 1992
|
Percent area covered with aquatic vegetation (PAC, %) |
6 |
|
Percent of lake's volume filled with vegetation (PVI, %) |
1 |
|
Average emergent plant biomass (kg wet wt/m2) |
1.8 |
|
Average floating-leaved plant biomass (kg wet wt/m2) |
1.6 |
|
Average submersed plant biomass (kg wet wt/m2) |
2.0 |
|
Average width of emergent and floating-leaved zone (ft.) |
63 |
|
Average lake depth (m) |
3 |
Frequency that plant species occur in 10 evenly spaced transects around the lake.
|
Common Name |
Plant Species |
Frequency (%) |
|
slender spikerush |
Eleocharis baldwinii |
90 |
|
rush fuirena |
Fuirena scirpoidea |
80 |
|
bladderwort |
Utricularia foliosa |
80 |
|
fragrant water-lily |
Nymphaea odorata |
70 |
|
Florida bladderwort |
Utricularia floridana |
70 |
|
maidencane |
Panicum hemitomon |
60 |
|
dwarf arrowhead |
Sagittaria subulata |
50 |
|
St. John's wort |
Hypericum spp. |
50 |
|
banana-lily |
Nymphoides aquatica |
40 |
|
variable-leaf milfoil |
Myriophyllum heterophyllum |
40 |
|
pickerelweed |
Pontederia cordata |
30 |
|
variableleaf pondweed |
Potamogeton diversifolius |
30 |
|
water-pennywort |
Hydrocotyle umbellata |
20 |
|
water primrose |
Ludwigia octovalvis |
20 |
|
southern water-grass |
Hydrochloa caroliniensis |
20 |
|
spatterdock |
Nuphar luteum |
10 |
|
red ludwigia |
Ludwigia repens |
10 |
|
smartweed |
Polygonum hydropiperoides |
10 |
|
bog-moss |
Mayaca fluviatilis |
10 |
|
buttonbush |
Cephalanthus occidentalis |
10 |
|
willow |
Salix spp. |
10 |
|
water spikerush |
Eleocharis elongata |
10 |