mark d. munn nawqa nutrient effects team leader usgs washington water science center tacoma, wa
DESCRIPTION
Nutrient-Biota Interactions in Agriculturally Dominated Landscapes: Lessons from the USGS National Water-Quality Assessment (NAWQA) Program. Mark D. Munn NAWQA Nutrient Effects Team Leader USGS Washington Water Science Center Tacoma, WA. Nutrient Enrichment Effects on Stream Ecosystems. - PowerPoint PPT PresentationTRANSCRIPT
Nutrient-Biota Interactions in Agriculturally Dominated Landscapes: Lessons from the USGS National Water-Quality Assessment
(NAWQA) Program
Mark D. MunnNAWQA Nutrient Effects Team Leader
USGS Washington Water Science CenterTacoma, WA
Nutrient Enrichment Effects on Stream Ecosystems
Determine how biological communities and processes respond to varying levels of nutrient enrichment in streams from contrasting environmental settings.
1. Biological communities: nutrients, habitat, algae and invertebrates
2. Stream metabolism: dissolved oxygen production
3. Nitrogen cycling: transport, transformations, uptake
GeorgiaNebraska
Delaware
Indiana
Washington
EPA Nutrient Indicators
• Chlorophyll a*• Algal AFDW• Community
composition• Community metrics• Production/respiration• Secondary production• pH• DO
• Hydrologic studies• Nitrogen*• Phosphorus*• Nutrient ratios• Sediment composition• Temperature• Transparency/TSS*
Chlorophyll a [rock/wood, silt/sand, or seston]
NUTRIENT GRADIENT
BIO
LO
GIC
AL
RE
SP
ON
SE
Nutrient Gradient – Response Conceptual Model
Threshold
oligotrophic
eutrophic
IN and NE exceeded TP threshold
Phosphorus Gradient (TP mg/L)
0.001 0.01 0.1 1 10
Stu
dy
Un
its
DE
GA
IN
NE
WA
Nitrogen Gradient (TN mg/L)
0.01 0.1 1 10 100
Stu
dy
Un
it
DE
GA
IN
NE
WA
All study units exceeded nitrogen threshold
TN exceeded proposed EPA criteria at 76 to 96% of sites
0.7
1.5
Study Unit
WA NE IN GA DE
TN
(m
g/L
)
0
5
10
20
22
0.880.38 2.18 0.69 0.7176% 96% 87% 83% 96%
Proposed EPA Nutrient Criteria
TP exceeded proposed EPA criteria at 52 to 100% of sites
Study Unit
WA NE IN GA DE
TP
(m
g/L
)
0.0
0.5
1.0
1.5
2.02.53.0
Proposed EPA Nutrient Criteria
0.022 0.067 0.076 0.037 0.03193% 100% 67% 52% 89%
Seston CHLa exceeded proposed EPA criteria at 11 to 93% of sites
10
Study Unit
WA NE IN GA DE
Ses
ton
CH
La
(ug
/L)
0
20
40
60
80Proposed EPA Nutrient Criteria
1.78 3 2.7 0.93 3.7541% 93% 11% 32% 28%
Chlorophyll a varied by substrate
WA NE IN GA DE
Ben
thic
CH
La
(mg
/m2)
0
20
40
60
80
100
Rock-WoodSilt-Sand
National TP-CHLa relationship exists, …
TP (mg/L)
0.001 0.01 0.1 1 10
Ses
ton
Ch
loro
ph
yll
a (u
g/L
)
0.1
1
10
100r2 = 0.11
…but distinct regional differences.
TP (mg/L)
0.001 0.01 0.1 1 10
Ses
ton
Ch
loro
ph
yll a
(u
g/L
)
0.1
1
10
100GAWANEDE IN
Seston CHLa vs TP and TN in GA
0.010
0.100
1.0
10.0
TP (mg/L)
1.0 10.0
1.0
10.0
TN (mg/L)
SE
ST
ON
CH
LO
RO
PH
YL
L A
(u
g/L
)
SE
ST
ON
CH
LO
RO
PH
YL
L A
(u
g/L
)
.04
0.10.10.01
Spearman (rs) correlation matrix (N=142)
Habitat limits CHLa
ROCK/WOOD
CHLa
SILT/SAND
CHLa
SESTON
CHLa
TP 0.24 0.36 0.62
TN 0.14 0.10 0.15
BASE FLOW -0.02 -0.34 -0.34
TEMPERATURE -0.34 0.13 0.23
CANOPY -0.38 -0.43 -0.42
SUBSTRATE 0.44 0.37 -0.10
BFI = Base Flow Index, the ratio of base flow to total flow volume for a given year.
NUTRIENT CONCENTRATION
CH
LO
RO
PH
YL
L A
Nutrients control algae- nutrient limitation
Algae control nutrients-low nutrients due to uptake
Nutrient saturation- possible physical controls
Algae limited by physical processes - stream flow, light, sediment, etc.
oligotrophic
eutrophic
Implications for Nutrient Criteria
1. Nutrient concentrations and chlorophyll may not always provide the best indication of stream status.
2. Agricultural streams can be nutrient saturated and habitat limited.
3. Need sub-regional and/or stream-type specific predictive models that incorporate nutrients, habitat, and biological components.
Contact Information
Mark D. MunnWashington Water Science CenterU.S. Geological SurveyTacoma, WA 98402253-428-3600 [email protected]
National NAWQA:http://water.usgs.gov/nawqa/
Nutrient Effects Team: http://pubs.usgs.gov/fs/fs11803/