New Hampshire – Local Factors in
Ocean and Coastal Acidification.
Ken Edwardson
Coastal Marine Natural Resources and
Environment Commission
June 19th, 2017
How would I describe OCA in
Great Bay?
Ocean Acidification in the Gulf of Maine,
Dr. Joe Salisbury, UNH (March 20, 2017 )
2
Measures and Estuarine Drivers
• Measures
– Clean Water Act Assessments
– pCO2, Aragonite Saturation, pH
• Estuarine Drivers
– Atmospheric Loading
– Freshwater Inputs
– Temperature
– Nutrients
– Carbon Storage
3
pH Assessment
Draft 2016 305(b)/303(d)
Healthy
Unhealthy
Based on the Water
Quality Standards
8.5 < Waterbody > 6.5
*All other
marine waters
are unassessed.
4
pCO2 – Great Bay (GRBGB)
5
ΩAragonite – Great Bay (GRBGB)
6
pH
7
pH – Great Bay (GRBGB)
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
10.5
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016
pH
"Current" Line for
2016pH-24HR_MIN
pH-24HR_MAX
pH-GRAB
pH-Max-Magex
pH Max
pH Min
pH-Min-Magex
GREAT BAY - COND
APPR
(NHEST600030904-04-
05)
8
Atmospheric Loading Reductions
9
National Trends in Emissions
NHDES 2015. Acid Rain Status and Trends New Hampshire Lakes, Ponds and Rainfall.10
NH Trend in Precipitation Acidity
NHDES 2015. Acid Rain Status and Trends New Hampshire Lakes, Ponds and Rainfall.11
Loading reductions confirmedpH improvements slow
NHDES 2015. Acid Rain Status and Trends New Hampshire Lakes, Ponds and Rainfall.12
Loading reductions confirmedpH improvements slow
NHDES 2015. Acid Rain Status and Trends New Hampshire Lakes, Ponds and Rainfall.13
Why it matters
• Demonstrates that the Clean Air Act is being
successful.
• Demonstrates that those successes are slow.
• pH of the freshwater inputs to our estuaries are
likely improving.
14
Freshwater Inputs
Ocean Acidification in the Gulf of Maine,
Dr. Joe Salisbury, UNH (March 20, 2017 ) 15
Annual Precipitation, Durham
(1900-2016)
Statistically significant (p=0.004) increase (~19%) from 1900-2016.
y = 0.062x - 80.344R² = 0.0696
0
10
20
30
40
50
60
70
1900 1920 1940 1960 1980 2000 2020
An
nu
al In
che
s o
f P
reci
pit
atio
n
16
Annual Precipitation Events,
> 1 inch in 24 Hours (1900-2016)
Non statistically significant (p=0.49) increase (~9%) from 1900-2016.
y = 0.007x - 4.0715R² = 0.0041
0
5
10
15
20
25
1900 1920 1940 1960 1980 2000 2020
Day
s th
at h
ave
Re
cord
er
Pre
cip
itat
ion
> 1
In
ch
Recorded Precip. > 1 inch in 24 hours
17
(2010 Spierre and Wake. Extreme
Precipitation Events for the
Northeastern United States 1948-
2007.)
Durham
18
Annual Precipitation Events,
> 0.5 inch in 24 Hours (1900-2016)
Statistically significant (p=0.009) increase (~20%) from 1900-2016.
y = 0.0411x - 53.951R² = 0.0574
0
5
10
15
20
25
30
35
40
45
50
1900 1920 1940 1960 1980 2000 2020
Day
s th
at h
ave
Re
cord
er
Pre
cip
itat
ion
>
0.5
Inch
Recorded Precip. > 0.5 inch in 24 hours
19
Annual Precipitation Events,
(1900-2016)
y = 0.231x - 342.24R² = 0.2209
0
20
40
60
80
100
120
140
160
1900 1920 1940 1960 1980 2000 2020
Day
s o
f R
eco
rde
r P
reci
pit
atio
n
Days with Recorded Precip.
Statistically significant (p<0.001) increase (~28%) from 1900-2016.20
Why it matters
• Increased precipitation brings increased runoff
of acidifying compounds and nutrients.
• Increased storm size shortcuts the natural
infiltration and filtering process of acidifying
compounds and nutrients.
21
Annual Freshwater Flow (1935-2016)
Non statistically significant (p = 0.17 and 0.22) increases (~15-17%) from 1935-2016.
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
1930 1940 1950 1960 1970 1980 1990 2000 2010 2020
An
nu
al A
vera
ge F
low
(cf
sm)
Oyster River,01073000
Oyster River,+0.0031 cfsm/year(p=0.18)
Lamprey River,01073500
Lamprey River,+0.0027 cfsm/year(p=0.22)
22
Why it matters.
• Increased runoff reflects the precipitation and
brings increased runoff of acidifying
compounds and nutrients.
• Increased runoff decreases estuarine salinity
and buffering thereby decreasing the potential
for shell formation.
23
Water Temperature
24
Squamscott River – GRBSQ
(July, August, September)
y = 0.1118x - 202.08R² = 0.2956
0
5
10
15
20
25
30
2000 2005 2010 2015
Tem
pe
ratu
re (
C)
95th Percentile
Median
5th Percentile
Linear (Median)
Almost statistically significant (p=0.055) increase (~6%) from 1900-2015. 25
Great Bay – GRBGB
(July, August, September)
Not statistically significant (p=0.85) increase (~0.5%) from 1900-2015.
y = 0.0087x + 3.6158R² = 0.0034
0
5
10
15
20
25
30
2000 2005 2010 2015
Tem
pe
ratu
re (
C)
95th Percentile
Median
5th Percentile
Linear (Median)
26
Why it matters.
• Increased temperature would increase the
potential aragonite saturation.
• Increased temperature is among the stressors to
native marine life.
27
Nutrients
28
Great Bay Total Nitrogen
(GRBAP, GRBGB, GRBSQ)
NHDES 2017. Technical Support Document for the Great Bay Estuary Aquatic Life Use Support
Assessments, 2016 305(b) Report/303(d) List. 29
Great Bay Total Nitrogen
(GRBGB)
NHDES 2017. Technical Support Document for the Great Bay Estuary Aquatic Life Use Support
Assessments, 2016 305(b) Report/303(d) List. 30
Great Bay Chlorophyll a
(GRBAP, GRBGB, GRBSQ)
NHDES 2017. Technical Support Document for the Great Bay Estuary Aquatic Life Use Support
Assessments, 2016 305(b) Report/303(d) List. 31
NHDES 2017. Technical Support Document for the Great Bay Estuary Aquatic Life Use Support
Assessments, 2016 305(b) Report/303(d) List.
Great Bay Chlorophyll a(GRBGB)
32
NHDES 2017. Technical Support Document for the Great Bay Estuary Aquatic Life Use Support
Assessments, 2016 305(b) Report/303(d) List.
Great Bay Dissolved Oxygen (mg/L)(GRBAP, GRBGB, GRBSQ)
33
Summer Minimums
NHDES 2017. Technical Support Document for the Great Bay Estuary Aquatic Life Use Support
Assessments, 2016 305(b) Report/303(d) List.
Great Bay Dissolved Oxygen (mg/L)(GRBGB)
34
Summer Minimums
NHDES 2017. Technical Support Document for the Great Bay Estuary Aquatic Life Use Support
Assessments, 2016 305(b) Report/303(d) List.
Great Bay Dissolved Oxygen (% Sat.)(GRBAP, GRBGB, GRBSQ)
35
NHDES 2017. Technical Support Document for the Great Bay Estuary Aquatic Life Use Support
Assessments, 2016 305(b) Report/303(d) List.
Great Bay Dissolved Oxygen (% Sat)(GRBGB)
36
Nutrient/Dissolved Oxygen –
pH Signal?
37
Example: 2012, GRGSQ
7.0
7.2
7.4
7.6
7.8
8.0
8.2
8.4
0
2
4
6
8
10
12
14
16
18
20
7/30 8/1 8/3 8/5 8/7 8/9 8/11 8/13
pH
Dis
solv
ed
Oxy
gen
(m
g/L)
DissolvedOxygen(mg/L)
pH
38
Photosynthesis/respiration in control:
high salinity, minimal flush, large pH
swings
Tide in control: lower salinity, higher flush,
smaller pH swings, better pH overall
pH
39
pH – Great Bay (GRBGB)
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
10.5
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016
pH
"Current" Line for
2016pH-24HR_MIN
pH-24HR_MAX
pH-GRAB
pH-Max-Magex
pH Max
pH Min
pH-Min-Magex
GREAT BAY - COND
APPR
(NHEST600030904-04-
05)
40
pH – Squamscott/Great Bay (GRBSQ)
41
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
10.5
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016
pH
"Current" Line for
2016pH-24HR_MIN
pH-24HR_MAX
pH-GRAB
pH-Max-Magex
pH Max
pH Min
pH-Min-Magex
SQUAMSCOTT
RIVER NORTH
(NHEST600030806-01-
02)
Eelgrass Carbon Sequestration?
Decreasing sequestration capacity.
NHDES 2017. Technical Support Document for the Great Bay Estuary Aquatic Life Use Support
Assessments, 2016 305(b) Report/303(d) List. 42
Ocean Acidification Measures the
Great Bay Estuary
Factors for Acidification Trend
pCO2 No data
Aragonite Saturation No data
pH Trends analysis not
attempted.
43
Ocean Acidification Stressors
Great Bay EstuaryFactors for
Acidification
Trend Implication Management
NOx and SOx in
Precipitation
Reduced. Improves pH 1o - Global
2o - Local
Total Precip. Increasing Decreases pH 1o – Global/Local
Storm Size Increasing in New
England
(except Durham)
Decreases pH 1o – Global/Local
Annual Flow Increasing Decreases pH 1o – Global/Local
Water
Temperature
Not detected in Great
Bay
(GOM increasing)
Could improve pH
(but add stressors)
1o - Global
2o - Local
Nutrient Load High but some areas
decreasing and more
decreases coming.
Decreases will improve
pH
1o - Local
2o - Global
Eelgrass Reduced Decreases pH
(lost carbon storage)
1o - Local
2o - Global44
Summary
• Calcifies in NH estuaries are at risk.
• Some local stressors getting better.
• Some local stressors getting worse.
• Local opportunities to promote resilience.
45
Discussion?
Contact Information:
Ken Edwardson
Senior Scientist
Watershed Management Bureau
New Hampshire Department of Environmental Services
(603) 271-8864
46
47
48
Living Seagrass
Biomass MgC ha-1
(mean +/- 95%CI)
Soil Corg MgC ha-1
(mean +/- 95%CI) Source
North
Atlantic0.85 (+/- 0.19) 48.7 (+/- 14.5)
Fourqurean et al.
2012
Global
Average2.51 (+/- 0.49) 194.2 (+/- 20.2)
Fourqurean et al.
2012
Mass. Eelgrass
Meadows0.25-3.0 12-50 EPA 2014/2015
Eelgrass Carbon Sequestration
49
Sediment Carbon Accumulation Rates
Site Accumulation Rate
(g/cm2/yr)
Core age (yrs)
Great Bay 1.0 20
Gloucester 0.12 100+
Cohasset 0.2 100
Pleasant Bay 0.3 80
Ninigret Pond 0.35 40
EPA 2017. Zosterapalooza.50
pH – Great Bay (GRBGB)
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
10.5
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016
pH
"Current" Line for 2016
pH-24HR_MIN
pH-24HR_MAX
pH-GRAB
pH-Max-Magex
pH Max
pH Min
pH-Min-Magex
Monthly Median, pH-
GRABMonthly Median, pH-
24HR_MAXMonthly Median, pH-
24HR_MIN
GREAT BAY - COND
APPR
(NHEST600030904-04-
05)
51
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
0 1 2 3 4 5 6 7 8 9 10 11 12
pH
Month
pH-24HR_MAX
pH-24HR_MIN
Monthly Median, pH-
24HR_MAX
Monthly Median, pH-
24HR_MIN
pH-Max-Magex
pH Max
pH Min
pH-Min-Magex
GREAT BAY - COND
APPR
(NHEST600030904-04-
05)
52
pH – Great Bay (GRBGB)
pH – Great Bay (GRBGB)
53
pH – Squamscott/Great Bay (GRBSQ)
54
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
0 1 2 3 4 5 6 7 8 9 10 11 12
Flo
w (
cfsm
)
pH
Month
pH-24HR_MAX
pH-24HR_MIN
Monthly Median,
pH-24HR_MAX
Monthly Median,
pH-24HR_MIN
pH-Max-Magex
pH Max
pH Min
pH-Min-Magex
Monthly Median,
Flow (cfsm)
SQUAMSCOTT
RIVER NORTH
(NHEST600030806-01-
02)