Island (Marion County)
Florida LAKEWATCH Water Chemistry Summary
Location: Latitude 29°28'36", Longitude 81°58'30"
Period of record: 93 sampling dates; October 12, 1988 to December 19, 1997
Surface area (Shafer et al. 1986): 136 acres / 55 hectacres
Lake Region (Griffith et al. 1997): Trail 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 St. John’s Offset 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Supplemental, unpublished water chemistry data, University of Florida.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 |
6.1 |
Sulfate (mg/L) |
6.8 |
|
Total alkalinity (mg/L as CaCO3) |
1.1 |
Calcium (mg/L) |
2.0 |
|
Conductance (µS/cm @ 25 °C) |
65 |
Magnesium (mg/L) |
1.0 |
|
Color (Pt-Co units) |
9 |
Sodium (mg/L) |
7.0 |
|
Chloride (mg/L) |
12.5 |
Potassium (mg/L) |
1.0 |
|
Silicon (mg/L) |
0.4 |
|
|
Long-term Florida LAKEWATCH Data
Numbers reported below are the minimum, average, and maximum value for the 93 months sampled:
|
|
Minimum |
Average |
Maximum |
|
Long-term total phosphorus concentrations (µg/L) |
5 |
11 |
40 |
|
Long-term total nitrogen concentrations (µg/L) |
180 |
290 |
540 |
|
Long-term total chlorophyll concentrations (µg/L) |
1.0 |
4.0 |
15.7 |
|
Long-term Secchi depth (ft) |
2.5 |
7.8 |
15.5 |
Florida LAKEWATCH data were not collected in 1999.
Island (Marion County)
Florida LAKEWATCH Aquatic Plant Summary
Aquatic plant data collected on May 7, 1992
|
Percent area covered with aquatic vegetation (PAC, %) |
0 |
|
Percent of lake's volume filled with vegetation (PVI, %) |
0 |
|
Average emergent plant biomass (kg wet wt/m2) |
0.9 |
|
Average floating-leaved plant biomass (kg wet wt/m2) |
0.9 |
|
Average submersed plant biomass (kg wet wt/m2) |
0.1 |
|
Average width of emergent and floating-leaved zone (ft.) |
21 |
|
Average lake depth (m) |
3 |
Frequency that plant species occur in 15 evenly spaced transects around the lake.
|
Common Name |
Plant Species |
Frequency (%) |
|
pickerelweed |
Pontederia cordata |
73 |
|
water-pennywort |
Hydrocotyle umbellata |
73 |
|
maidencane |
Panicum hemitomon |
67 |
|
spatterdock |
Nuphar luteum |
53 |
|
red ludwigia |
Ludwigia repens |
53 |
|
rush fuirena |
Fuirena scirpoidea |
53 |
|
sawgrass |
Cladium jamaicense |
47 |
|
fragrant water-lily |
Nymphaea odorata |
33 |
|
lemon bacopa |
Bacopa caroliniana |
33 |
|
torpedograss |
Panicum repens |
33 |
|
St. John's wort |
Hypericum spp. |
33 |
|
water-shield |
Brasenia schreberi |
27 |
|
smartweed |
Polygonum hydropiperoides |
27 |
|
bog-moss |
Mayaca fluviatilis |
20 |
|
buttonbush |
Cephalanthus occidentalis |
20 |
|
para grass |
Brachiaria mutica |
20 |
|
pipewort |
Eriocaulon spp. |
20 |
|
cat-tail |
Typha spp. |
13 |
|
water primrose |
Ludwigia octovalvis |
13 |
|
red root |
Lachnanthes caroliniana |
13 |
|
rush spp. |
Juncus acuminatus |
13 |
|
slender spikerush |
Eleocharis baldwinii |
7 |
|
banana-lily |
Nymphoides aquatica |
7 |
|
dwarf arrowhead |
Sagittaria subulata |
7 |
|
variable-leaf milfoil |
Myriophyllum heterophyllum |
7 |
|
willow |
Salix spp. |
7 |