83www.HoosierRiverwatch.com
GO BELOW TO:
The purpose of this taxonomic key is to assist volunteer monitors, who are not trained in taxonomy, with theidentification of benthic macroinvertebrates found in Indiana. This key is a simplified version of morecomplex keys. The taxonomic level of this key is intended for use by citizen monitoring groups. Whenusing this key please note that each couplet offers two or three options. Each couplet is numbered and thenumbers in bold refer to the next couplet (the next set of numbers that you proceed to).
Please be aware that some macroinvertebrates may have missing body partsso you should look at more than one organism!
(1)a Has a shell(s)2
(4)a Right-handed opening RIGHT-HANDED SNAIL
Right-Handed Snail
(4)b Left-hand opening LEFT-HANDED SNAIL
Left-Handed Snail
(1)b Has no shell 5
(2)a Has a hinged double shell
(2)b Has a single shell 4
(3)a Adult under 2 inches long 19
(3)b About 2-4 inches long MUSSEL
Taxonomic Key toBenthic Macroinvertebrates
CHOOSE ONE:
3
Mussel
84 www.HoosierRiverwatch.com
GO BELOW TO:6(5)a Has a segmented body or looks like a tiny tick
(5)b Has an unsegmented body and has an "arrowshaped" head; 2 pigment spots (eyes)
PLANARIA
Planaria
(6)a No obvious legs 7
(6)b Obvious legs
(7)a Has no obvious appendages (long, tubular body)
12
8
(7)b Has some appendages (small tubes, tiny bumps,or feathery structures)
9
LEECH(8)a Has a smooth body and suckers Leech
RAT-TAILED MAGGOTRat-Tailed Maggot
(8)b Has a round body and a rat tail
(8)c Has a rounded body AQUATIC WORMS
Aquatic Worms
CRANE FLY LARVA(9)a Body black or brown; more than 1/3 inch long;plump and catepillar-like
(9)b Has a distinct head 10
CHOOSE ONE:
BLACK FLY LARVA(10)a One end of body wider than otherend; two tiny feather structures on smaller end
Black Fly Larva
Crane Fly Larva
85www.HoosierRiverwatch.com
GO BELOW TO:CHOOSE ONE:
(10)b No difference in diameter along body 11
(11)a Bright red body BLOOD MIDGESBlood Midge
(11)b Grey Body OTHER MIDGES
(12)a Has four pairs of legs WATER MITE
Water Mite
(12)b Has three pairs of legs 13
(12)c Has many pairs of legs 26
(13)a Has no wings or short wing pads on back 14
(13)b Has two pairs of wings that cover the abdomen 23
WATER PENNY BEETLELARVA
(14)a Has a flat, round body with legsunderneath (wings are not obvious)
Water Penny
(14)b Not flat, has long body with legs 15
(15)a Lives in a tube or a case or has twohooks in its last segment and is greenwith 3 plates on back behind head.(The "green caddisfly" builds a net &tube, but will be washed into thekick net as "free living")
CADDISLY LARVA
Caddisfly Larva
(15)b Free-living 16
86 www.HoosierRiverwatch.com
GO BELOW TO:CHOOSE ONE:(16)a Abdomen possesses lateral filaments
similar in size to legs21
(16)b Abdomen does not have "leg-like"filaments (may have feathery "gills")
17
(17)a Always with only twotail appendages and noabdominal gills
STONEFLY NYMPHStoneflyNymph
(17)b Usually has three tail appendages, andwith no lateral gills on abdominalsegments
18
(17)c Tail has no appendages 25
MAYFLY NYMPH(18)a Has long, bristle-like tail appendages,sometimes 2 or 3
Mayfly Nymph
(18)b Lower lip formed into extensible scoop-like structure and has leaf-like tailappendages
DAMSELFLY NYMPH
Damselfly Nymph
20
(19)b Small triangular shell with alternatingcream and dark brown bands
ZEBRA MUSSEL (EXOTIC)
(20)a Numerous very fine concentric rowsof elevated lines, white or creamcolored, with smooth lateral teeth(ridge lines on inside near point)
FINGERNAIL CLAM
(19)a Small rounded shell (< 2 inches)
Fingernail Clam
Zebra Mussel
(20)b Numerous concentric elevated ridges,yellowish brown to black shell withserrated lateral teeth
ASIATIC CLAM (EXOTIC)
Asiatic Clam
87www.HoosierRiverwatch.com
CHOOSE ONE:
(21)a Head narrower than widest bodysegments
BEETLE LARVA
(21)b Head as wide or wider than other bodysegments
22
(22)a Abdomen with single long filament at end ALDERFLY
(22)b Abdomen ending with a pair of tinyhooked legs, large head with pincer-likejaws
DOBSONFLY OR FISHFLY
Dobsonfly Larva
(23)a Oval shaped body, legs with featheryswimming hairs
ADULT WATER BUGS ANDWATER BEETLES
(23)b All legs smooth, without hairs, crawling RIFFLE BEETLE ADULT
Riffle Beetle Adult
GO BELOW TO:
(25)a Lower lip formed into scoop like structure
Dragonfly Nymph
(25)b Looks like a tiny millipede RIFFLE BEETLE LARVA
Riffle Beetle Larva
DRAGONFLY NYMPH
Beetle larva
Alderfly
Water bug
(26)a Flattened top to bottom, crawling lookslike "roly-poly" or a "pill bug"
SOWBUG
(26)b Flattened side to side, swimming lookslike tiny shrimp
SCUD
Sowbug
Scud or Side-swimmer
Key
to M
acro
inve
rteb
rate
Life
in th
e Ri
ver
spira
l, op
ening
on le
ftco
nical
larg
e, 2
to 8
inch
es,
dark
-colo
red
long b
reathi
ngtub
etw
o frin
ged
“tails
”sm
ooth,
“stif
f,”sm
all he
adlar
ge, g
rey w
ithten
tacles
distin
ct he
ad,
red, g
reen o
rtan
, twi
stsbig
“hea
d,”ac
tive
black
, atta
ches
toha
rd su
rface
swh
ite or
grey
with
tentac
les
coile
dsp
iral,
open
ing on
righ
t
Single
Shell
Shell
s
Doub
le Sh
ell
Gille
d Sn
ail
Pouc
hSn
ail
Orb
Snai
l
Lim
pet
Pill
orFi
nger
nail
Clam
Fres
hwat
er
Mus
sel
Rat t
aile
dM
aggo
tLa
rva
Wat
erSn
ipe
Fly
Larv
aHo
rse
Fly
Larv
aCr
ane
Fly
Larv
a
Cran
e Fl
yLa
rva
Mid
geLa
rva
Mid
gePu
paBl
ack
Fly
Larv
a
reddis
h bro
wn,
segm
ented
body
gli
des a
long
botto
m, bo
dyno
t seg
mente
d
tan to
brow
n,lon
gSu
cker
s, ex
pand
s an
d con
tracts
, bod
yse
gmen
ted
Leec
hTu
bife
xW
orm
Flat
wor
mor
Plan
aria
Hors
ehai
rW
orm
small
, hair
-like,
swim
s in “
S” sh
ape
Nem
atod
e or
Thre
adw
orm
roun
dsw
ims w
ith a
jerk,
using
anten
nas
apos
troph
e-sh
aped Cyclo
psor
Cope
pod
Seed
and
Clam
Shri
mp
Wat
er F
lea
or D
aphn
ia
shrim
p-like
,sw
ims o
n side
walks
on bo
ttom
lobste
r-like
Cray
fish
Aqua
ticSo
wbu
g or
Isop
od
runs
on
top of
wate
rtin
y, of
tenbr
ightly
color
ed
Wat
erM
iteFi
shin
gSp
ider
small
, cra
wls
on bo
ttom
back
legs
mov
e at
same
time
sw
ims o
n su
rface
“Cra
wls”
thro
ugh
water
, spo
tted
Riff
leBe
etle
Wat
erSc
aven
ger
Beet
le
Pred
aceo
usDi
ving
Beet
leW
hirl
igig
Beet
le
Craw
ling
Wat
er B
eetle
dark
,liv
es on
surfa
cegr
aspin
g fro
nt leg
s, up
to th
ree in
ches
swim
s on b
ack,
back
whit
esw
ims r
ight-s
ide-up
,ba
ck bl
ack
long,
stick
-like
Wat
erSt
ride
r
Gian
tW
ater
Bug
Back
swim
mer
Wat
erBo
atm
an
Wat
erSc
orpi
on‘R
anat
ra’
Scud
or
Amph
ipod
swim
s mov
ing
hind l
egs a
ltern
ating
gree
n, tan
,or
ange
orwh
ite bo
dy
sucti
on cu
p-lik
elar
ge bo
dy,
hinge
d mou
thliv
es in
stick
hous
eliv
es in
ston
eca
se
Pyra
lidCa
terp
illar
Wat
erPe
nny
Drag
onfly
Larv
a
Cadd
isfly
Larv
a
Cadd
isfly
Larv
a
six le
gs an
dpr
olegs
onab
dome
n
long “
tails,
” gills
onab
dome
nlon
g “tai
ls,” g
ills
on ab
dome
nlar
ge le
gs,
feathe
ry gi
llspla
te-lik
e “tai
ls,”
no gi
lls on
abdo
men
May
flyLa
rva
May
fly La
rva
Dam
selfl
yLa
rva
dark
head
, gree
n or
tan bo
dy, t
wobr
ush-l
ike ta
ils
large
mou
th pa
rts,
“spin
es” o
n side
“tails
” lon
g an
d stif
f, lon
gan
tenna
s
flat g
ills
on ab
dome
n
Cadd
isfly
Larv
aAl
derf
lyLa
rva
Dobs
onfly
Larv
aSt
onef
lyLa
rva
May
flyLa
rva
small
, “s
pines
” on s
ide
Legs
With
Tenta
cles,
Brus
hes
or “T
ails”
10+
Legs
Four
Pairs
of Le
gsTh
ree P
airs o
f Leg
s
Beetl
e-Like
, Wing
s Har
dLe
ather
y Wing
s
Thre
e “Ta
ils”
One o
r Two
“Tail
s”No
Obv
ious “
Tails
”
No W
ings
Worm
-Like
Micro
scopic
No Sh
ells
Wing
s
No Le
gs
tan, li
ves o
nsu
rface
Mar
shTr
eade
r
long b
reathi
ng tu
be,
gras
ping f
ront
legs
Wat
erSc
orpi
on‘N
epa’
hang
s fro
m su
rface
,lar
ge m
outh
parts
Pred
aceo
usDi
ving
Bee
tleLa
rva
(Size
s of i
llustr
ation
s are
not
prop
ortio
nal.)
body
with
brist
les,
no su
cker
s
brow
n, lea
therli
ke,
six le
gs, u
suall
y“C
”-sha
ped
side v
iewof
“tails
”
small
, whit
ish,
tan or
brow
n
Cadd
isfly
Larv
a
Riff
leBe
etle
Larv
a
Deve
lope
d by
the
Univ
ersit
y of
Wisc
onsin
–Ex
tens
ion
in co
oper
atio
n wi
th th
e W
iscon
sinDe
partm
ent o
f Nat
ural
Res
ourc
es. B
ased
on
ake
y de
velo
ped
by R
iver
edge
Nat
ure
Cent
er,
Newb
urg,
WI.
May
be re
prod
uced
with
this
cred
it fo
r edu
catio
nal,
non-
prof
it pu
rpos
es.
For i
nfor
mat
ion,
cont
act U
WEX
Env
ironm
enta
lRe
sour
ces C
ente
r, 60
8/26
2-26
34. U
nive
rsity
of W
iscon
sin-E
xten
sion
is an
EEO
/Affi
rmat
ive
Actio
n em
ploy
er a
nd p
rovi
des e
qual
opp
ortu
ni-
ties i
n em
ploy
men
t and
pro
gram
min
g, in
cludi
ngTi
tle IX
and
ADA
requ
irem
ents.
May
flyLa
rva
Bris
tleW
orm
89www.HoosierRiverwatch.com
How to Complete theBiological Monitoring Data Sheet
The first portion of the Biological Monitoring Data Sheet is the information section. For instructionson how to complete this section, see pages 108-111 in Chapter 7 Data Reporting.
Sampling ProceduresEquipment: Check one or both of the nets used to collect macroinvertebrate sample.Habitat: Check each type of habitat sampled during this survey.
Pollution Tolerance IndexThe macroinvertebrate index is divided into Pollution Tolerance Groups (PT Group) 1,2,3 and 4.These PT groups represent the different levels of pollution tolerance. The higher the group number,the higher the pollution tolerance level. Record the number of macroinvertebrates you find here.
The next row is the # of Taxa. Insects that have the same body shape all belong to the same taxa (seethe back of your PTI macroinvertebrate data sheet for general body shape/taxa). To find the totalnumber of taxa for each PT Group you need to add the number of types of organisms. It is possible tohave a particular PT group without any numbers, therefore it will score a zero.
Do not make the mistake of adding the numbers of organisms together.
PT GROUP 1 PT GROUP 2 PT GROUP 3 PT GROUP 4 Intolerant Moderately Intolerant Fairly Tolerant Very Tolerant
Stonefly Nymph ________ Damselfly Nymph ________ Midge Larvae ________ Left-Handed Snail ________
Mayfly Nymph ________ Dragonfly Nymph ________ Black Fly Larvae ________ Aquatic Worms ________
Caddis Fly Larvae ________ Sowbug ________ Planaria ________ Blood Midge ________
Dobsonfly Larvae ________ Scud ________ Leech ________ Rat-tailed Maggot ________
Riffle Beetle ________ Crane Fly Larvae ________
Water Penny ________ Clams/Mussels ________
Right-Handed Snail ________ Crayfish ________
# of TAXA ______ # of TAXA ______ # of TAXA ______ # of TAXA ______
The next row is the group scores. Multiply each # of taxa by its weighting factor.
# of TAXA ______ # of TAXA ______ # of TAXA ______ # of TAXA ______
(x 4) ______ (x 3) ______ (x 2) ______ (x 1) ______
Note: The Volunteer Stream Monitoring Internet Database (described in Chapter 7) will perform thesecalculations for you when you submit data.
Weighting
Factors:
4 2 2 2
4 2 2 216 6 4 2
6
10
30
15
2
>100
16
15 25
90 www.HoosierRiverwatch.com
Other Biological IndicatorsCheck the appropriate box if you find native mussels, zebra mussels, rusty crayfish or submerged aquaticplants at your site. Estimate the percentage of rocks or the stream bottom covered by algae at your site. Writeyour Diversity Index score if you perform the procedures described on pages 95-96.
Then total all of the group scores to get the POLLUTION TOLERANCE INDEX RATING.
POLLUTION TOLERANCEINDEX RATING(Add the final index values for each group.)
23 + Excellent17 - 22 Good11 - 16 Fair10 or Less Poor
# of TAXA ______ # of TAXA ______ # of TAXA ______ # of TAXA _______
(x 4) ______ (x 3) ______ (x 2) ______ (x 1) ______
Other Biological Indicators
_______ % Algae Cover
_______ Diversity Index
NativeMussels
ZebraMussels
RustyCrayfish
Aquatic Plants
4 2 2 2
16 6 4 2
28
25 0.75
PT GROUP 1 PT GROUP 2 PT GROUP 3 PT GROUP 4 Intolerant Moderately Intolerant Fairly Tolerant Very Tolerant
Stonefly Nymph ________ Damselfly Nymph ________ Midge Larvae ________ Left-Handed Snail ________
Mayfly Nymph ________ Dragonfly Nymph ________ Black Fly Larvae ________ Aquatic Worms ________
Caddis Fly Larvae________ Sowbug ________ Planaria ________ Blood Midge ________
Dobsonfly Larvae ________ Scud ________ Leech ________ Rat-tailed Maggot ________
Riffle Beetle ________ Crane Fly Larvae ________
Water Penny ________ Clams/Mussels ________
Right-Handed Snail________ Crayfish ________
# of TAXA ________ # of TAXA ________ # of TAXA ________ # of TAXA ________
(x 4) ________ (x 3) ________ (x 2) ________ (x 1) ________
23 or More Excellent17 - 22 Good11 - 16 Fair10 or Less Poor
Weighting
Factors:
POLLUTION TOLERANCEINDEX RATING(Add the final index values for each group.)
POLLUTION TOLERANCE INDEX (PTI)
Example of a complete Pollution Tolerance Index:
6
30
15
2
>100
16
15
1025
416
2 2 26 4 2
28
91www.HoosierRiverwatch.com
BIOLOGICAL MONITORING DATA SHEET
Date ____/____/____ Begin Time _____:_____ (am/pm) # Adults __________________
End Time _____:_____ (am/pm) # Students ________________
Certified Monitors' Names____________________________________ Volunteer ID_______________
Organization Name ___________________________________________________________________
Watershed Name _______________________________________ Watershed # __ __ __ __ __ __ __ __
Stream/River Name ____________________________________________ Site ID ________________
MM DD YY
(Above ID numbers are required.) (Please do not abbreviate.)
Riffles
Leaf Packs Snags/Vegetation
Undercut Banks Sediment
Other
Check Habitats Sampled
Kick Seine Net (3 times)
D-Net (20 jabs or scoops)
Check Methods Used
PT GROUP 1 PT GROUP 2 PT GROUP 3 PT GROUP 4 Intolerant Moderately Intolerant Fairly Tolerant Very Tolerant
Stonefly Nymph ________ Damselfly Nymph ________ Midges ________ Left-Handed Snail ________
Mayfly Nymph ________ Dragonfly Nymph ________ Black Fly Larvae ________ Aquatic Worms ________
Caddis Fly Larvae________ Sowbug ________ Planaria ________ Blood Midge ________
Dobsonfly Larvae ________ Scud ________ Leech ________ Rat-tailed Maggot ________
Riffle Beetle ________ Crane Fly Larvae ________
Water Penny ________ Clams/Mussels ________
Right-Handed Snail________ Crayfish ________
# Of TAXA ________ # Of TAXA ________ # Of TAXA ________ # Of TAXA ________
(x 4) ________ (x 3) ________ (x 2) ________ (x 1) ________
23 or More Excellent17 - 22 Good11 - 16 Fair10 or Less Poor
Weighting
Factors:
POLLUTION TOLERANCEINDEX RATING(Add the final index values for each group.)
POLLUTION TOLERANCE INDEX (PTI)
Other Biological Indicators
_______ % Algae Cover
_______ Diversity Index
NativeMussels
ZebraMussels
RustyCrayfish
Aquatic Plants
GROUP 4 – Very Tolerant of Pollution
GROUP 3 – Fairly Tolerant of Pollution
GROUP 2 – Moderately Intolerant of Pollution
GROUP 1 – Very Intolerant of Pollution
Stonefly Nymph Mayfly NymphRiffle BeetleAdult & Larva Caddisfly Larva
DobsonflyLarva Water Penny Larva
Right-Handed
Snail
Damselfly Nymph
DragonflyNymph
Scud
SowbugCranefly
Clam/Mussel
MidgeLarva
Planaria
Black Fly Larva
Leech
Aquatic Worms
Rat-tailedMaggot Blood Midge
LarvaLeft-HandedSnail
Macroinvertebrate Identification Key
2 tailslongantennae
3 tails
3 paddle-like (feathery) tails
no tailslarge eyes
flattened top tobottom (lookslike a pill bug)
flattenedside-ways& swimson side
caterpillar-shaped, ringed
large head &2 pinchers
lookslike a
suctioncup
makes a case fromtwigs, rocks, leaves
flattened &segmented
one end isswollen
bright red
2 eye spots& very small
top bottom
www.HoosierRiverwatch.com
verysmall
&hardshell
must bealive tocount
must bealive tocount
must bealive tocount
small, butvisible head
intense wiggler
segmented“earthwormy”
92
Crayfish
looks likea mini-lobster
fluttering gills
93www.HoosierRiverwatch.com
Metric Your Metric Result
2 1 0
A) Mayflies + Stoneflies + Most Caddisflies
Greater than 32.2
16.1-32.2 Less than 16.1
B) Common Netspinner Caddisflies
Less than 19.7 19.7-34.5 Greater than 34.5
C) Lunged Snails Less than 0.3 0.3-1.5 Greater than 1.5
D) Riffle Beetles + Water Pennies
Greater than 6.4
3.2-6.4 Less than 3.2
E) % Tolerant Less than 46.7 46.7-61.5 Greater than 61.5
F) % Non-Insects Less than 5.4 5.4-20.8 Greater than 20.8
Total # of 2s: Total # of 1s: Total # of 0s:
subtotals:Multiply by 2: Multiply by 1: Multiply by 0:
Add the 3 subtotals to get the Final Multimetric Index Score:
Acceptable Ecological Condition (7-12)Unacceptable Ecological Condition (0-6)
Virginia Save Our Streams Multimetric Index
Other Macroinvertebrate IndicesOnce you have identified the macroinvertebrates in your river or stream samples and noted the numberof each taxa, the data can easily be applied to more than one index. The metrics shown below weredeveloped for the Virginia Save OurStreams program through an extensiveresearch project by Sarah Engel and J.Reese Voshell at Virginia Tech. Theseexamples are provided for Riverwatchvolunteers purely for educational use.They provide an example of additionalinformation that can be obtained fromsamples properly collected and countedfor the Pollution Tolerance Index (PTI).
Since the final multimetric index ratingvalues or "scores" were based on ecologicalconditions in Virginia streams, they do notapply in Indiana. The final metric is only validfor shallow, rocky-bottom streams in the mid-Atlantic region of the U.S. However, we hopeto someday complete the research to develop amultimetric index for use in Indiana. If youwant to "try out" this index with your data,your sample must contain at least 200organisms for these metrics to be valid.
Metric A scores better when higher, since these are Group 1 organisms.
Metric B scores better when lower, since net spinners are more tolerant of pollution.
Metric C scores better when lower, since these are Group 4 organisms.
Metric D scores better when higher, since these are in Group 1.
Metrics E & F score better when lower, since these are more tolerant organisms (mostly Group 3 & 4).
The final index combines the resultsof the six individual metrics andweights them accordingly. Themultimetric index's final assessmentof ecological condition in Virginiastreams matched those of theprofessional biologist 95.5% of thetime. (Information on this page modifiedfrom Engel and Voshell, 2002.)
Taxon NumberDamselflies
Dragonflies Taxon NumberSowbugs Right-handed snailsScuds SowbugsClams ScudsAll Midges ClamsBlack Flies CrayfishPlanaria PlanariaLeeches LeechesLunged Snails Lunged SnailsAquatic Worms Aquatic WormsTotal Tolerant Total Non-InsectsTotal Tolerant divided by the total number of organisms in the sample
Total Non-Insects divided by the total number of organisms in the sample
Multiply by 100 (E) Multiply by 100 (F)
E) % Tolerant Organisms
F) % Non-Insects
Metric Number Counted
Total # of Organisms in the Sample
Final Percent
A) Mayflies + Stoneflies + Most Caddisflies
Divide by
Multiply by 100
B) Common Netspinner Caddisflies
Divide by
Multiply by 100
C) Lunged Snails - Orb + Left-handed + Limpets
Divide by
Multiply by 100
D) Riffle Beetles + Water Pennies
Divide by
Multiply by 100
Individual Macroinvertebrate Metrics
15
16
5
1
30
210 7.62
210
210
210
0.48
2.38
14.29
>10016125
157 157
210
74.76 20.95
210
16125
7.62
0.482.38
14.2974.7620.95
1 1 42 1 0
3
2
94www.HoosierRiverwatch.com
Met
ric
Your
Met
ric
Resu
lt2
10
A) M
ayfl
ies
+ St
onef
lies
+ M
ost C
addi
sflie
s
Gre
ater
than
32
.216
.1-3
2.2
Less
than
16.
1
B) C
ommo
n N
etsp
inne
r Ca
ddis
flie
s
Less
than
19.
719
.7-3
4.5
Gre
ater
than
34.
5
C) L
unge
d Sn
ails
Less
than
0.3
0.3-
1.5
Gre
ater
than
1.5
D) R
iffl
e Be
etle
s +
W
ater
Pen
nies
Gre
ater
than
6.
43.
2-6.
4Le
ss th
an 3
.2
E) %
Tol
eran
tLe
ss th
an 4
6.7
46.7
-61.
5G
reat
er th
an 6
1.5
F) %
Non
-Ins
ects
Less
than
5.4
5.4-
20.8
Gre
ater
than
20.
8
Tota
l # o
f 2s
:To
tal #
of
1s:
Tota
l # o
f 0s
:
subtotals:
Mul
tipl
y by
2:
Mul
tipl
y by
1:
Mul
tipl
y by
0:
Add
the
3 s
ubto
tals t
o ge
t th
e Fi
nal Multimet
ric
Inde
x Sc
ore:
Acce
ptab
le E
colo
gica
l Con
ditio
n (7
-12)
Una
ccep
tabl
e Ec
olog
ical
Con
ditio
n (0
-6)
Virg
inia S
ave
Our
Str
eams
Multimet
ric
Inde
x
Met
ric
Num
ber
Coun
ted
Tota
l # o
f Org
anisms
in
the
Sample
Fina
l Pe
rcen
t
A) M
ayfl
ies
+ S
tone
flie
s +
Mos
t Ca
ddis
flie
sDi
vide
by
Mul
tipl
y by
100
B) C
ommo
n N
etsp
inne
r Ca
ddis
flie
sDi
vide
by
Mul
tipl
y by
100
C) L
unge
d Sn
ails
- O
rb +
Le
ft-h
ande
d +
Lim
pets
Divi
de
byM
ulti
ply
by 1
00
D) R
iffl
e Be
etle
s +
W
ater
Pen
nies
Divi
de
byM
ulti
ply
by 1
00
Individu
al M
acro
inve
rteb
rate
Met
rics
Taxo
nNum
ber
Dams
elfl
ies
Drag
onfl
ies
Taxo
nNum
ber
Sow
bugs
Righ
t-ha
nded
sna
ilsSc
uds
Sow
bugs
Clam
sSc
uds
All M
idge
sCl
ams
Blac
k Fl
ies
Cray
fish
Plan
aria
Plan
aria
Leec
hes
Leec
hes
Lung
ed S
nails
Lung
ed S
nails
Aqua
tic W
orms
Aqua
tic W
orms
Tota
l Tol
eran
tTo
tal N
on-I
nsec
tsTo
tal T
oler
ant d
ivid
ed
by th
e to
tal n
umbe
r of
or
gani
sms
in th
e sa
mpl
e
Tota
l Non
-Ins
ects
div
ided
by
the
tota
l num
ber
of
orga
nism
s in
the
sam
ple
Mul
tipl
y by
100
(E)
Mul
tipl
y by
100
(F)
E) %
Toler
ant
Org
anisms
F) %
Non
-Ins
ects
Virg
inia S
ave
Our
Str
eams
Multimet
ric
Inde
x
Dis
clai
mer
: Th
ese
indi
ces
can
be u
sed
by H
oosi
er R
iver
watc
hvo
lunt
eers
for
edu
cati
onal
use
and
pra
ctic
e in
det
erm
inin
g a
mul
tim
etri
c bi
otic
inde
x. T
he r
atin
g sc
ale
used
in th
e fi
nal
mul
tim
etri
c in
dex
was
deve
lope
d fo
r Vir
gini
a st
ream
s an
d is
not
valid
for
use
in d
eter
min
ing
over
all s
trea
m h
ealt
h in
Ind
iana
.
95www.HoosierRiverwatch.com
Macroinvertebrate Diversity IndexThe Diversity Index does not require benthic macroinvertebrate identification. This index measuresstream water quality by distinguishing organisms by color, size and shape. The only distinction ismade between the number of runs, and the number of different types (taxa) of organisms.
1. Collect macroinvertebrates using the Kick Seine or Dip Net sampling procedures and place them ina jar with water or a preservative and randomize them by swirling.
2. Make a grid of 4-6 cm squares on the bottom of a white tray.
3. Pour the sample from the jar into the white tray, spreadingthe macroinvertebrates evenly over the tray.
4. Randomly select a starting grid and begin picking outorganisms in a random sequence. Pick out all the specimensfrom one square before moving to the next square. If youpicked all of the specimens from one square and there were less than 50 organisms in the square,move to the next square and pick all of the organisms from that square to add to the first. You musthave at least 50 organisms to complete the test procedures.
5. Place the selected organisms in another tray and compare them two at a time. You will bedetermining if the next insect is like or different from the previous organism. To complete the"Organism" row, place an "X" in the box if the organism you are comparing is like the previousorganism and a "O" if it is different from the previous organism. Fill in the X and O boxes untilyou have compared 50 organisms.
6. To complete the "Run" row, record a number each time a change from "X" to "O", or "O" to "X"occurs. An example is shown below. Note: Always place an "X "in the first box for your firstorganism, and always begin with the number one for your first run.
CalculationsDetermine the total number of runs and the total number of organisms (usually 50). Divide the numberof runs by the number of organisms to determine the Diversity Index. (Note: The diversity index is thesame as the Sequential Comparison Index printed in the first edition of this manual).
Diversity = Number of runs = 7 = .78 = GoodIndex Number of organisms 9
Diversity Index Results
0.0 - 0.3 Poor0.3 - 0.6 Fair0.6 - 1.0 Good
X O X O O X O X X
1 2 3 4 5 6 7 Run
Organism
96www.HoosierRiverwatch.com
Diversity Index Results
0.0 - 0.3 Poor0.3 - 0.6 Fair0.6 - 1.0 Good
Sample 1
Run
Organism
Run
Organism
Run
Organism
Total Number of Runs: __________
Total Number of Organisms: __________
Divide # Runs to get Diversity Index Results: __________
Diversity Index Results
0.0 - 0.3 Poor0.3 - 0.6 Fair0.6 - 1.0 Good
# Organisms
Sample 2
Run
Organism
Run
Organism
Run
Organism
Total Number of Runs: __________
Total Number of Organisms: __________
Divide # Runs to get Diversity Index Results: __________ # Organisms