CODEORGANISMNTiTv
FLWFlatworm 6.0
AQWAquatic Worm 10.0
LEELeech 8.0
SBGSowbug 6.0
SCDScud 4.0
DGFDragonfly 4.5
DM1Broadwinged Damselfly 3.5
DM2Narrowwinged Damselfly 5.5
HLLDobsonfly 5.5
ALFAlderfly 7.5
MF1Torpedo Mayfly 3.0
MF2Swimming Mayfly 4.0
MF3Clinging Mayfly 3.5
MF4Crawling Mayfly 5.5
MF5Burrowing Mayfly 5.0
MF7Armored Mayfly 3.0
MF6Other Mayfly 3.0
STFStonefly 1.5
CF1Hydropsychid Caddisfly 5.5
CF2Snail Case Caddisfly 3.0
CF3Saddle Case Caddisfly 0.0
CF4Other Caddisfly 3.5
RFBRiffle Beetle 5.0
WHBWhirligig Beetle 4.0
WPBWater Penny Beetle 4.0
CRFCrane Fly 4.0
BIMBiting Midge 5.0
BLWBloodworm Midge 11.0
MIDMidge 6.0
BLFBlack Fly 6.0
SNFSnipe Fly 4.0
OTFOther Fly 10.0
LHSLeft-Handed Snail 9.0
RHSRight-Handed Snail 7.0
PLSPlanorbid Snail 6.5
LIMLimpet 7.0
OPSOperculate Snail 6.0
  TOTALS  

Macroinvertebrate Biotic Index Calculator

This tool automates the calculation of the Macroinvertebrate Biotic Index as an indicator
of water quality. Javascript must be enabled on your browser.
Enter number of organisms in the N column at left, then click Calculate.
Click on an aquatic orgnism for an identification guide. Nonindicator species are shown here.
 

ORGANISMS SAMPLED=∑N =
TAXA RICHNESS = ∑TAXA =
EPT TAXA RICHNESS =
MBI = ∑Tv ÷ ∑N =


Tentative Quality Ratings: Revised 2004
  Taxa RuchnessEPT Taxa RuchnessMBI
Excellent>= 14>= 5<= 4.35
Good12 - 1344.36 - 5.00
Fair9 - 1135.01 - 5.70
Poor7 - 825.71 - 6.25
Very Poor<= 60 - 1>= 6.26

NOTES (MNT)


**PLEASE VERIFY YOUR DATA SHEETS**

CITIZEN SCIENTIST INITIALS _______________ DATE ____________
CITIZEN SCIENTIST INITIALS _______________ DATE ____________
RW STAFF INITIALS _______________ DATE ____________

This guide is designed to aid Illinois RiverWatch Citizen Scientists to identify stream macroinvertebrates.
Only those stream indicator taxa used in the assessment of stream quality by Illinois RiverWatch are
listed in this guide. Not all macroinvertebrates collected can be identified with this guide.

The use of these organisms for stream quality assessment is restricted to the state of Illinois.

Size ranges given are for mature individuals.

Photography: C. Nixon, M. Jeffords, P. Nixon, and M. Rosales
Illustrations: C. Nixon and Loren Kirkwood
Designed by Peter Chen for Illinois RiverWatch Stream Monitoring.