How does excessive nitrogen
loading effect the health and
resiliency of Long Island’s
coastal ecosystems?
Christopher J. G...
“Nitrogen is the critical limiting factor to
primary producers in Long Island coastal
marine waters”
– Dr. John Ryther, Wo...
Population, Suffolk County, NY, USA
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
1,400,000
1,600,000
1900 1910 19...
Septic tank
Water table
/ aquifer
Nitrogen
In Suffolk County:
• 70% of homes have
septic tanks or
cesspools.
• ~70% of N l...
0
1
2
3
4
1987 2005
Nitrogencontent(mg/L)
Glacial Magothy
Changes in groundwater nitrogen levels in Suffolk County
40%
inc...
N loads to Great South Bay from watershed
•~70% of N entering Moriches and Shinnecock Bay is from wastewater
(Gobler et al...
> 22
18
12
6
< 0.3
4.8
4.8
2.8 2.8
3.1
2.4
3.0
Groundwater nitrogen concentrations,
Eastern Bays
Total N mg L-1
> 22
18
12
6
< 0.3
Groundwater N and buildings
Total N mg L-1
> 22
18
12
6
< 0.3
Groundwater N and agriculture
Total N mg L-1
Pine Barrens
South shore bay nitrogen loads
compared to other water bodies
NYSDEC assessment of Long Island coastal waters
Impaired
Minor impacts
No known impacts
What impairments are brought about by
excessive nitrogen loading?
• Loss of critical habitats: Eelgrass, salt marshes
• Lo...
The vital role of salt marshes in coastal
ecosystems and communities
Salt marsh ecosystems
Salt marshes protect coastlines
Chris Bason, Delaware Center for the Inland Bays
Salt marshes protect coastlines
Healthy marsh Nitrogen loaded marsh
“Coastal eutrophication as a driver of salt marsh loss”, Deegan et al 2012, Nature
Den...
0
10
20
30
40
50
60
70
80
90
Manhasset,KingsPoint
Manhasset,PlumPoint
Manhasset,ManorHaven
SouthManhassetBay
NissequogueRi...
Salt marsh loss, Jamaica Bay
Flooding during
Hurricane Sandy
Flooding in Mastic – Shirley during
Hurricane Sandy
Salt
marsh
Salt
marsh
Each point is a home.
Flooding in Mastic – Shirley, sea level rise
Salt
marsh
Each point is a home.
Flooding scenarios will worsen significantly...
Eelgrass:
Critical benthic
habitat
NYS seagrass, 1930 - 2030
NYSDEC Seagrass Taskforce Final Report, 2010; Suffolk County assessment, 2014
0
50,000
100,000
1...
Take a deep breath…
Oxygen (O2)
Carbon dioxide (CO2)
Phytoplankton
CH2O + O2 CO2 + H2O
Respiration
Nitrogen loading leads to low oxygen and high CO2
Nitrogen loading
Consumed ...
Dissolved oxygen (mg L¯¹)
pCO2 (µatm)
Long Island Sound, August 2013
The Forge River, NY, USA
0
1
2
3
4
7
7.1
7.2
7.3
7.4
7.5
7.6
6/30/2012 7/10/2012 7/20/2012 7/30/2012 8/9/2012 8/19/2012
Di...
Effects of high CO2 and low O2 on fish survival
0
10
20
30
40
50
60
70
80
90
Control Low pH Low DO Low pH, Low DO
%Surviva...
Samples for eelgrass genetic analysesHarmful algal blooms across Long Island
PSP, DSP PSP,
DSP
Cochlodinium
Cochlodinium
C...
Samples for eelgrass genetic analyses
Aureococcus
‘Brown tide’
Cochlodinium
‘Rust tide’
Alexandrium
‘Red tide – PSP’
Dinop...
Alexandrium red tides and paralytic shellfish
poisoning (PSP)
Alexandrium
Saxitoxin
Presence of PSP-producing Alexandrium
in NY: 2007-2013
= cells not detected
= < 100 cells L-1
= > 1,000 cells L-1
= 100 - ...
Waste
water
N
“Sewage-derived nitrogen loading promotes
intense and toxic Alexandrium blooms.”
Nitrogen impacts on shellfish
• Landings of clams and scallops have declined 99% since 1980.
• Linkages to nitrogen driven...
Conclusion:
Excessive nitrogen loading leads to…
• Loss of critical habitats: Salt marshes, eelgrass
• Low dissolved oxyge...
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Nitrogen Pollution and The Future of Long Island By Prof. Christopher Gobler

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How does excessive nitrogen loading effect the health and resiliency of Long Island’s coastal ecosystems?

Loss of critical habitats: Eelgrass, salt marshes
Low dissolved oxygen levels, hypoxia
Acidification, low pH
Macroalgal blooms: Sea lettuce, Ulva
Toxic algal blooms: Red, rust, brown tides
Loss or depletion of shellfisheries and finfisheries

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Nitrogen Pollution and The Future of Long Island By Prof. Christopher Gobler

  1. 1. How does excessive nitrogen loading effect the health and resiliency of Long Island’s coastal ecosystems? Christopher J. Gobler
  2. 2. “Nitrogen is the critical limiting factor to primary producers in Long Island coastal marine waters” – Dr. John Ryther, Woods Hole Oceanographic Institute, Science Magazine, 1971
  3. 3. Population, Suffolk County, NY, USA 0 200,000 400,000 600,000 800,000 1,000,000 1,200,000 1,400,000 1,600,000 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Population New York City >25,000,000 lbs of nitrogen per year from human waste
  4. 4. Septic tank Water table / aquifer Nitrogen In Suffolk County: • 70% of homes have septic tanks or cesspools. • ~70% of N loads come from septic tanks and cesspools. Loading of wastewater nitrogen to coastal waters Nitrogen Groundwater flow
  5. 5. 0 1 2 3 4 1987 2005 Nitrogencontent(mg/L) Glacial Magothy Changes in groundwater nitrogen levels in Suffolk County 40% increase 200% increase Suffolk County Comprehensive Water Resources management plan, 2010
  6. 6. N loads to Great South Bay from watershed •~70% of N entering Moriches and Shinnecock Bay is from wastewater (Gobler et al, in progress for NYSDOS). Kinney and Valiela, 2011 Septic tanks, cesspools Atmosphere Fertilizer
  7. 7. > 22 18 12 6 < 0.3 4.8 4.8 2.8 2.8 3.1 2.4 3.0 Groundwater nitrogen concentrations, Eastern Bays Total N mg L-1
  8. 8. > 22 18 12 6 < 0.3 Groundwater N and buildings Total N mg L-1
  9. 9. > 22 18 12 6 < 0.3 Groundwater N and agriculture Total N mg L-1 Pine Barrens
  10. 10. South shore bay nitrogen loads compared to other water bodies
  11. 11. NYSDEC assessment of Long Island coastal waters Impaired Minor impacts No known impacts
  12. 12. What impairments are brought about by excessive nitrogen loading? • Loss of critical habitats: Eelgrass, salt marshes • Low dissolved oxygen levels, hypoxia • Acidification, low pH • Macroalgal blooms: Sea lettuce, Ulva • Toxic algal blooms: Red, rust, brown tides • Loss or depletion of shellfisheries and finfisheries
  13. 13. The vital role of salt marshes in coastal ecosystems and communities
  14. 14. Salt marsh ecosystems
  15. 15. Salt marshes protect coastlines Chris Bason, Delaware Center for the Inland Bays
  16. 16. Salt marshes protect coastlines
  17. 17. Healthy marsh Nitrogen loaded marsh “Coastal eutrophication as a driver of salt marsh loss”, Deegan et al 2012, Nature Dense, strong roots Nutrient weakened, roots
  18. 18. 0 10 20 30 40 50 60 70 80 90 Manhasset,KingsPoint Manhasset,PlumPoint Manhasset,ManorHaven SouthManhassetBay NissequogueRiver StonyBrookHarbor FlaxPond MountSinaiHarbor Peconics,CoreyCreek Peconics,CedarBeachCreek SouthOysterBay,GilgoIs. SouthOysterBay,GooseIs. WesternBays,MiddleBay WesternBays,EastBay Percentlosssince1974 Loss of wetlands on Long Island, since 1974 NYSDEC survey data Nassau County, North Shore Suffolk County, North Shore East end Suffolk County South Shore Nassau County South Shore
  19. 19. Salt marsh loss, Jamaica Bay
  20. 20. Flooding during Hurricane Sandy
  21. 21. Flooding in Mastic – Shirley during Hurricane Sandy Salt marsh Salt marsh Each point is a home.
  22. 22. Flooding in Mastic – Shirley, sea level rise Salt marsh Each point is a home. Flooding scenarios will worsen significantly with weakened or destroyed salt marshes. Salt marsh
  23. 23. Eelgrass: Critical benthic habitat
  24. 24. NYS seagrass, 1930 - 2030 NYSDEC Seagrass Taskforce Final Report, 2010; Suffolk County assessment, 2014 0 50,000 100,000 150,000 200,000 1930 2009 2030 Acresofseagrass 90% loss Extinction in NY Increasing Nitrogen Loading
  25. 25. Take a deep breath… Oxygen (O2) Carbon dioxide (CO2)
  26. 26. Phytoplankton CH2O + O2 CO2 + H2O Respiration Nitrogen loading leads to low oxygen and high CO2 Nitrogen loading Consumed Produced
  27. 27. Dissolved oxygen (mg L¯¹) pCO2 (µatm) Long Island Sound, August 2013
  28. 28. The Forge River, NY, USA 0 1 2 3 4 7 7.1 7.2 7.3 7.4 7.5 7.6 6/30/2012 7/10/2012 7/20/2012 7/30/2012 8/9/2012 8/19/2012 Dissolvedoxygen (mgL-1) pH(totalscale) pH Dissolved oxygen
  29. 29. Effects of high CO2 and low O2 on fish survival 0 10 20 30 40 50 60 70 80 90 Control Low pH Low DO Low pH, Low DO %Survival Larval Inland Silversides High CO2 Low O2 High CO2, low O2
  30. 30. Samples for eelgrass genetic analysesHarmful algal blooms across Long Island PSP, DSP PSP, DSP Cochlodinium Cochlodinium Cochlodinium PSP Brown tideCochlodinium PSP, red tide DSP, red tide PSP PSP Toxic blue green algae Toxic blue greens Toxic blue greens Ulva Ulva Ulva DSP
  31. 31. Samples for eelgrass genetic analyses Aureococcus ‘Brown tide’ Cochlodinium ‘Rust tide’ Alexandrium ‘Red tide – PSP’ Dinophysis ‘Red tide – DSP’ Enhanced nutrient loading more intense &/or toxic HABs Gobler et al 2012 Gobler et al 2011; Gobler and Sunda 2012 Hattenrath et al 2010 Hattenrath- Lehmann 2014 Microcystis ‘Blue green algae’ Harke and Gobler, 2013
  32. 32. Alexandrium red tides and paralytic shellfish poisoning (PSP) Alexandrium Saxitoxin
  33. 33. Presence of PSP-producing Alexandrium in NY: 2007-2013 = cells not detected = < 100 cells L-1 = > 1,000 cells L-1 = 100 - 1,000 cells L-1 **circles represent the highest observed densities at each site** • Alexandrium found at 47 of 63 sites samples (75%)
  34. 34. Waste water N “Sewage-derived nitrogen loading promotes intense and toxic Alexandrium blooms.”
  35. 35. Nitrogen impacts on shellfish • Landings of clams and scallops have declined 99% since 1980. • Linkages to nitrogen driven HABs, habitat loss, and water quality degradation. 0 100,000 200,000 300,000 400,000 500,000 600,000 700,000 800,000 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 Hard clam landings (bushels) in Great South Bay
  36. 36. Conclusion: Excessive nitrogen loading leads to… • Loss of critical habitats: Salt marshes, eelgrass • Low dissolved oxygen levels, hypoxia • Acidification, low pH • Macroalgal blooms: Sea lettuce, Ulva • Toxic algal blooms: Red, rust, brown tides • Loss or depletion of shellfisheries and finfisheries

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