A Nutrient Biotic Index (NBI) for Usewith Benthic Macroinvertebrate

Communities

A Nutrient Biotic Index (NBI) for UseA Nutrient Biotic Index (NBI) for Usewith Benthic Macroinvertebratewith Benthic Macroinvertebrate

CommunitiesCommunitiesA.J. Smith, R.W. Bode, and G.S. Kleppel

NYS DEC Stream BiomonitoringA.J. Smith, R.W. Bode, and G.S. KleppelA.J. Smith, R.W. Bode, and G.S. Kleppel

NYS DEC Stream BiomonitoringNYS DEC Stream Biomonitoring

OutlineOutline• Development of the NBI

– Deriving Nutrient Optima

– Creating Scale of Eutrophication

– Impairment Thresholds

– Brief Comparison w/Diatoms

Nutrient Biotic IndexNutrient Biotic Index• Question

– How can we estimate the degree of enrichment?

• Nutrient Biotic Index– Linear Scale of Eutrophication

• Oligotrophic Eutrophic

• Importance– Assist in reporting– Assist in site prioritizing– Nutrient criteria

Nutrient Biotic IndexNutrient Biotic Index• 1993 - 2002• 185 different sampling events

– 129 different Locations– On 116 different streams– Chemistries and Invertebrates

Nutrient Biotic IndexNutrient Biotic Index• Chemistries were averaged

– Within 90 days prior to invertebratesampling date

– Split NO3- and TP values into Bins

(ranges)• 15 bins• Between 11 and 14 sites in each

Nutrient Biotic IndexNutrient Biotic Index

• Weighted Averaging used theproportion of times a taxon waspresent w/in bins

– Established nutrient optima

• Basis for tolerance values

• Site Index scores are calculated usingtolerance values

Nutrient Biotic IndexNutrient Biotic Index

Acroneuria abnormisTP optimum = 0.0151 mg/lTolerance Value = 0

TP Bin Ranges (mg/l)

0.00890.0120

0.01510.0175

0.01930.0233

0.02950.0366

0.04730.0565

0.06500.0927

0.10750.1633

0.5558

Freq

uenc

y of

Occ

urre

nce

0

1

2

3

4

5

Nutrient Biotic IndexNutrient Biotic Index

Gammarus sp.TP optimum = 0.1017 mg/lTolerance Value = 8

TP Bin Ranges (mg/l)

0.00890.0120

0.01510.0175

0.01930.0233

0.02950.0366

0.04730.0565

0.06500.0927

0.10750.1633

0.5558

Freq

uenc

y of

Occ

urre

nce

0

2

4

6

8

10

B1B2

B3B4

B5B6

B7

B8

B9B10

B11

B12B13

B14B15

Additive tree cluster of Nitrate binsbased on mean pair-wise Bray-Curtis similarity

Additive tree cluster of Nitrate binsbased on mean pair-wise Bray-Curtis similarity

Eutrophic> 0.98 mg/l

Mesotrophic> 0.24 – 0.98 mg/l

Oligotrophic< 0.24 mg/l

B1

B2B3

B4

B5

B6B7

B8

B9B10

B11

B12B13

B14B15

Additive tree cluster of Total P binsbased on mean pair-wise Bray-Curtis similarity

Additive tree cluster of Total P binsbased on mean pair-wise Bray-Curtis similarity

Eutrophic> 0.065 mg/l

Mesotrophic> 0.0175 - 0.065 mg/l

Oligotrophic< 0.0175 mg/l

NBI-N and NitrateNBI-N and Nitrate

NO3- Trophic State

Oligotrophic Mesotrophic Eutrophic

NB

I-N S

core

0

1

2

3

4

5

6

7

8

9

10

(0.24mg/l) (0.98mg/l) (5.66mg/l)

NBI-P and TPNBI-P and TP

TP Trophic State

Oligotrophic Mesotrophic Eutrophic

NB

I-P S

core

0

1

2

3

4

5

6

7

8

9

10

(0.065 mg/l)(0.0175 mg/l) (0.556 mg/l)

Water Quality - NitrateWater Quality - Nitrate

NO3- Trophic State

Oligotrophic Mesotrophic Eutrophic

Perc

ent o

f Sam

ples

0

10

20

30

40

50

60

70

Non ImpactedSlightly ImpactedModerately Impacted

Water Quality - TPWater Quality - TP

TP Trophic State

Oligotrophic Mesotrophic Eutrophic

Per

cent

of S

ampl

es

0

10

20

30

40

50

60

70

Non ImpactedSlighty ImpactedModerately Impacted

Impairment ThresholdsImpairment Thresholds• Meso/Eutrophic boundaries

– Nitrate• > 0.98 mg/l• NBI-N Score > 6.0

– Total Phosphorus• > 0.065 mg/l• NBI-P Score > 6.1

NBI-P and DTINBI-P and DTI

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35Summ.TP

3

4

5

6

7

TPsc

ore

0.0

0.2

0.4

0.6

0.8

1.0

DTI

TPscoreDTI

DTI Score

0.0 0.2 0.4 0.6 0.8 1.0

NB

I-P S

core

0

2

4

6

8

10

NBI-P Score = 2.99 + 4.15(DTI Score)r = 0.82; p < 0.0001; n = 32

ConclusionsConclusions• NBIs provide a meaningful measure of

enrichment

• Trophic state boundaries have directrelationship with biota

• Together they provide monitoring andenforcement mechanisms for nutrientcriteria

• Similarity to diatom indices shows promise

AcknowledgementsAcknowledgements• Bob Bode, Margaret Novak, Larry Abele, and

Diana Heitzman

• Scott Stoner

• Ken Markussen, and NYC SDWF

• Gary Kleppel, George Robinson

• Karen Riva-Murray, Pat Phillips, Doug Burns,Barry Baldigo, Mike McHale