Biological
Conditions
The health of fish and macroinvertebrate (i.e., animals without
backbones that are larger than the size of a pencil dot) communities
is a strong indication of overall stream health.
Since the mid-1990's many natural resources professionals working
in the Anacostia watershed have monitored these communities
using an Index of Biotic Integrity or IBI approach.
The IBI compares the fish and macroinvertebrate communities
of urban streams with those of healthy reference streams, incorporating
geographical, ecosystem, community, and population, as well
as distribution and abundance variables that account for differences
in waterbody size, type, and region of occurrence. |
| The
table on the right shows adjusted IBI scores and verbal ratings
for the Anacostia River and its tributaries. While there are
still many gaps in the Anacostia macroinvertebrate and fish
community IBI databases, available data have proven extremely
valuable in the restoration effort. |
|
| Fish |
Macroinvertebrates |
| Scores
|
Verbal
Rating |
Scores
|
Verbal
Rating |
| 47
- 50 |
Excellent
|
36
- 40 |
Excellent
|
| 35
- 46 |
Good
|
27
- 35 |
Good
|
| 23
- 34 |
Fair |
17
- 26 |
Fair |
| 0
- 22 |
Poor
|
0
- 16 |
Poor
|
|
|
Click on the following links for graphs
showing biological conditions in the
tidal portion of the Anacostia River.
There are currently no Fish
IBI
results for the tidal
portion of the Anacostia River.
However, approximately 47 fish
species are known to inhabit the tidal
portion of the
river.
There
are currently no
Macroinvertebrate
IBI
results for the
tidal
portion of the Anacostia River.
|
|
|
|
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