Explanation of Indicator
The Florida Department of Environmental Protection (DEP) classifies shellfishing waters into six categories based on sanitary, hydrographic, meteorological, and bacteriological surveys. The categories are: 1) approved; 2) conditionally approved; 3) restr
icted; 4) conditionally restricted; 5) prohibited; and 6) unclassified (waters not yet surveyed to determine classification). Many of Florida's shellfishing waters have been affected by increased urbanization along the shoreline, and some of these wat
ers have been closed to harvesting of shellfish because of water quality problems. In tracking the numbers of shellfishing waters in each classification, a trend can be established in the water quality of shellfishing waters.
Data Characteristics
SOURCE
The information is compiled by Bob Thompson, Bureau of Marine Resource Regulation and Development, Florida Department of Environmental Protection, who can be contacted at 3900 Commonwealth Boulevard, Mail Station 205, Tallahassee, Florida 32399-3000, or a
t (904) 488-5471.
ACQUISITION
Data can be obtained in hard copy format at no cost.
COLLECTION
The bacteriological water quality of shellfish areas in Florida is monitored at least monthly, and annual reports summarize sanitary conditions. Hydrography, meteorology, pollution source, and bacteriological surveys are documented in comprehensive repor
ts written every five years. These comprehensive reports are the basis for updating shellfish harvesting area classifications in the Florida Administrative Code. Physical, chemical, and bacteriological water quality data are available for all shellfish
harvesting areas currently open. AutoCAD, a computer mapping system, is used to make maps that illustrate shellfish classifications.
Data Limitations
Care must be taken to not assume a direct causal relationship between shellfish waters classification and overall water quality. Shellfish classifications can be influenced by water quality; however, water quality is affected by both human (e.g., stormwa
ter runoff) and natural (e.g., rainfall) activities.
Data Analysis
A total of 1,638,941 acres of shellfish harvesting areas have been classified statewide. This is 59,179 more acres than were classified in 1992, a 3.75 percent increase. Only 222,604 acres, or 13.58 percent of the classified waters, were approved for ha
rvesting as of July, 1994. This is a 40,946 acre, or 15.5 percent, decrease from the 1992 approved acreage of 263,550. As of July, 1994, there were 785,228 acres, or 47.91 percent, in a conditionally approved category; this is an 11.5 percent increase f
rom the 704,421 acres conditionally approved in 1992. The acreage of restricted and conditionally restricted areas also increased in 1994, from 122,243 to 126,920 acres, representing 7.74 percent of the total. Roughly 31 percent, or 504,189 acres, were
classified as prohibited in 1994.
It is apparent that even though the total acreage of classified shellfishing waters has increased, the number of approved acres has decreased. The three categories which have increased since 1992 are conditionally approved, conditionally restricted, and prohibited. Since 1992, the quality of shellfishing waters appears to be declining.
Classification March, 1992 July, 1994
Approved 263,550 222,604
Conditionally Approved 704,421 785,228
Restricted 94,982 80,274
Conditionally Restricted 27,261 46,646
Prohibited 489,548 504,189
Total Acreage 1,579,762 1,638,941