Studies of algal and
macroinvertebrate communities have been among DEP's most cost-effective and
successful assessment tools of overall system health. Advantages of using algae
and benthic invertebrates include their ease of sampling, their strategic
positions in the food web, and their ability to respond quickly (within days or
weeks) of a human physical or water quality disturbance.
Macroinvertebrate Community Health
measurements of macroinvertebrate community health are routinely employed to
determine the status of a system. These are:
- Taxa richness: the number of
different types of organisms present in a system.
- Shannon-Weaver diversity: an
index which is specified in the Florida Administrative Code as a measure of
- Percent contribution of the
dominant taxon: related to diversity, used for analysis of qualitative samples.
- Numbers of pollution
sensitive taxa: several different invertebrate indices based on this principle,
including the Florida Index and the Lake Condition Index.
Ephemeroptera/Plecoptera/Trichoptera Index: am index which sums the number of
these kinds of organisms present. A related parameter, the
Ephemeroptera/Plecoptera/Odonata Index, is also sometimes used.
- Community structure:
measurements of shifts in proportions of major groups of organisms, compared to
- Trophic composition/feeding
guilds: determination of shifts in the feeding strategies of invertebrates.
- The Stream Condition Index
for Florida (SCI): a composite macroinvertebrate index made up of several of the
measurements listed above.
- Habitat Assessment: quality
of the local environment with respect to the needs of the organisms
The Standard Operating
Procedures used in performing benthic macroinvertebrate analyses can be viewed
or downloaded from the
Biology Section SOPs.