To successfully manage ecosystems, a basic
understanding of the system's biological components is mandatory. The biota
respond to a wide variety of cumulative factors, both natural and anthropogenic.
As the organisms integrate these factors over time, a characteristic community
structure emerges. When human actions adversely affect a system, the biological
population will change, leading to an imbalanced community. For example,
pollution sensitive taxa will disappear, taxa richness and diversity usually
decrease, food webs are disturbed, and undesirable nuisance species may
The Biological Assessment
Subsection is responsible for the analysis of
benthic macroinvertebrate communities. These data,
along with several other aspects of the system (algal biology and community
assessment, nutrient chemistry, physical/chemical attributes, sediment
characteristics, toxicity, microbiological communities, habitat assessment, land
use, and historical information), provide a multi-disciplinary approach to the
evaluation of water quality.
DEP Programs That Utilize
Fifth Year Inspection
Point source dischargers are
required to renew their permit every five years. How does a permit writer know
if a given discharge is environmentally acceptable or if more stringent permit
restrictions are needed? Historically, they had to rely on fairly limited data,
mainly provided by the permittee. For the past seven years, the Department has
depended upon a highly successfully bioassessment program to provide additional
information for permitting decisions.
A comprehensive study of the
effluent and its effects on the receiving water biological communities is
performed several months before the permit expires. Toxicity bioassays are
conducted on the effluent, which is also analyzed for priority pollutants and
metals. Benthic macroinvertebrates and algal communities are examined at a
reference station (usually upstream of the discharge) and at a potentially
affected station (located within the influence of the discharge). An objective
habitat assessment is performed at both test sites to ensure comparability of
biological sampling stations. Other parameters include fecal coliform bacteria,
sediment analysis, algal growth potential, and nutrients.
The data are evaluated, using
several measurements of community health, to determine possible violations of
Florida Water Quality Standards. These include: biological integrity
(diversity), imbalances of flora or fauna, dominance of nuisance species,
toxicity, and individual chemical/bacteriological numeric criteria. A succinct
report, summarizing the findings, is written and sent to appropriate regulatory
staff, who recommend ways to correct any problems uncovered by the studies.
Forestry Best Management
Practices (BMP) Program
Conducted in conjunction with
the Florida Department of Agriculture and Consumer Services, Division of
Forestry, this study was designed to determine the effectiveness of
silvicultural best management practices. A minimum of six stream segments in
four separate streams were sampled prior to logging activities, and again
approximately one year later, after clear-cutting, site preparation, and
planting had occurred. Several additional streams subject to silvicultural
activities were sampled throughout the state, to determine overall success of
Forestry BMP Studies
For these studies,
biological, physical, chemical, and habitat information is collected from
several stations throughout a drainage basin. The sampling sites are selected to
assess the effects of human activities in the watershed, which may include point
source discharges or stormwater inputs from urban or agricultural areas. The
results may be used for permitting, compliance, or ecosystem management
Basin Study Summaries
The practice of environmental
mitigation, which involves human restoration or creation of aquatic systems, has
increased in recent years. The former Bureau of Wetlands Resource Management had
developed various compliance criteria for mitigation activities associated with
specific dredge and fill permits, however, assurance that these criteria were
sufficient for the re-establishment of healthy biological populations at the
affected sites was largely unavailable. The Biology Section conducted three
studies (sampled between 1991 and 1994) to evaluate the success of various
created wetlands and stream restoration activities.
Mitigation Study Summaries
Florida TMDL Studies
The Clean Water Act, Section
303(d), requires states to identify impaired water bodies and develop a
wasteload allocation known as a Total Maximum Daily Load (TMDL) to reduce
pollutants to a level sufficient to protect water quality of the system. The
Department has gathered data from numerous sources to develop and prioritize a
list of these impaired water bodies. Due to the limited data available for many
systems, additional study was requested, to refine the list and more accurately
determine the systems where a full TMDL study was needed.
TMDL Study Summaries
Marine Bioassessment Program
The Florida Estuarine and
Marine Biological Assessment Methods-Development Program has completed the
initial series of technical workshops. The files below contain the results of
the workshops to date. From these workshops came proposed measures of community
health for different habitats and the proposed methods for sampling those
measures. Field trials to test those methods and measures are under development.
- Overview of status of DEP bioassessment methods-development program and estuarine/marine technical workshops to date.
overview.pdf (PDF, 14kB)
- Report from habitat-based bioassessment workshop held April 1999.
habitatrpt.pdf (PDF, 1.5 MB)
- Summary and overview report for indicator-group workshops held fall 1998. Individual workshop reports are below.
summaryrpt.pdf (PDF, 10 kB)
- Report from corals bioassessment workshop held October 1999.
coralrpt.pdf (PDF, 25 kB)
- Report from submerged aquatic vegetation (SAV) bioassessment workshop held October 1999.
savreport.pdf (PDF, 24 kB)
- Report from benthic macroinvertebrate bioassessment workshop held November 1999
invertrpt.pdf (PDF, 29 kB)