Nitrogen pollution in Long Island’s coastal waters – impacts and solutions

Long Island and the gravity of water

Our groundwater is our drinking water

The beauty of Long Island waters

The bounty of Long Island fisheries

The richness of our maritime culture

Menhanden, 1700s, 1800s

Oysters, 1800s, 1900s

Whaling, 1700s, 1800s

Clamming, 1900s

How are things looking these days?

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

2004

2006

0

100,000

200,000

300,000

400,000

500,000

600,000

700,000

800,000

Hard Clam landings from Great South Bay in bushels

NY bay scallop landings

The end of our maritime culture?

How are things looking these days?

Riverhead turtle die-off, May 2015, linked to red tide, saxitoxin

Riverhead fish kill, June 2015, linked to nitrogen loading, algal blooms, low oxygen

Brown tide, south shore, July 2015, linked to shellfish mortality

Point Lookout, seaweed bloom, August 2015, unsightly, contributes to low oxygen,

low pH

Great Peconic Bay, rust tide, September 2015, linked to fish mortality

All of Long Island is a watershed -Materials on land eventually enter our groundwater and

surface water.

1980 1990 2000 2010 20202

2.2

2.4

2.6

2.8

3

3.2

3.4

3.6

3.8

Nitr

ogen

(mg/

L)

Expanding population, nitrogen levels

Suffolk County groundwater

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 20100

200,000

400,000

600,000

800,000

1,000,000

1,200,000

1,400,000

1,600,000Population of Suffolk County

Septic tanks,

cesspools

Many impairments associated with nitrogen overload

Impaired

Minor impacts

No known impacts

Salt marsh ecosystems

Salt marshes protect coastlines

Salt marsh

Salt marsh

Salt marshes protect coastlines

Salt marshes protect coastlines

Flooding during Hurricane Sandy

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

Manhasset, K

ings Point

Manhasset, Plum

Point

Manhasset, M

anor Haven

South Manhasset B

ay

Nissequogue R

iver

Stony Brook H

arbor

Flax Pond

Mount Sinai H

arbor

Peconics, Corey C

reek

Peconics, Cedar B

each Creek

South Oyster B

ay, Gilgo Is.

South Oyster B

ay, Goose Is.

Western B

ays, Middle B

ay

Western B

ays, East Bay

0

10

20

30

40

50

60

70

80

90

Perc

ent l

oss s

ince

197

4

Loss of wetlands on Long Island, since 1974

NYSDEC survey data

Nassau County, North Shore

Suffolk County, North Shore

East end Suffolk CountySouth Shore

Nassau CountySouth Shore

Salt marsh

Salt marsh

Salt marshes protect coastlines

Seagrass: Critical habitat for fish and shellfish

NYS seagrass, 1930 - 2030

NYSDEC Seagrass Taskforce Final Report, 2010; Suffolk County assessment, 2014

1930 2009 20300

50,000

100,000

150,000

200,000

Acre

s of s

eagr

ass

Extinction in NY

90% loss$200,000,000 lost annually (Johnston et al 2002).$10,000,000,000 lost since 1975.

Samples for eelgrass genetic analysesHarmful algal blooms across Long Island

Brown tide Rust TidePSP DSPToxic blue green algae Seaweeds

More nitrogen makes harmful algae on Long Island grow faster.

Brown tide

Toxic blue green algae

Studies: Hattenrath et al 2010; Gobler et al 2011, 2012; Gobler and Sunda 2012; Harke and Gobler 2013, 2015 Hattenrath-Lehmann et al 2015

1980 1990 2000 2010 20202

2.2

2.4

2.6

2.8

3

3.2

3.4

3.6

3.8

Nitr

ogen

(mg/

L)

Alexandrium red tides and paralytic shellfish poisoning

(PSP)

AlexandriumSaxitoxin

Wastewater

N

Wastewater-derived nitrogen loading promotes PSP in Long Island Sound.

-Hattenrath et al 2010, Harmful Algae

Saxitoxin

Presence of PSP-producing Alexandrium in LI and CT: 2007-2014

= 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**

~900 time points

• Alexandrium found at 49 of 65 sites samples (75%)

Nitrogen promotes in the water impairments: algal blooms, low oxygen

Clams Oysters Scallops Mussels

-100

-80

-60

-40

-20

0

Perc

ent d

eclin

e sin

ce 1

980

NYS landings of shellfish, 1980 – 2010

Losses due to nitrogen driven harmful algal blooms, seagrass loss, and water quality degradation.

Where is the nitrogen coming from?

Kinney and Valiela, 2011

Gobler and Stinnete, 2014

Where is the nitrogen coming from?

Stephen Lloyd, The Nature Conservancy, 2014

Where is the nitrogen coming from?

Stephen Lloyd, The Nature Conservancy, 2014

Where is the nitrogen coming from?

Crisis

Danger Opportunity

Center for Clean Water Technology

On-site wastewater disposal

…Engineering a solution…

Coupled septic tanks and leaching pit

CCWT Mission

• Develop and commercialize the next generation of nitrogen removal technology for septic systems– Improve efficiency of nitrogen removal– Reduce system costs– Minimize maintenance– Shrink the infrastructure

Alternative septic systems

Long Island’s Coastal Ecosystems

Nitrogen mitigation goal 2015

Conclusions

• Water is at the heart of the Long Island existence.

• Excessive nitrogen loading is causing ecosystem and economic harm across Long Island.

• Nitrogen loading reductions are needed to improve water quality.

Questions• Reducing nitrogen levels will be very difficult. Do we know it

will work? Are there success stories on Long Island regarding the reduction of nitrogen levels and water quality improvements?

• How long will it take to improve water quality conditions once we start reducing nitrogen levels?

• What can be done to improve water quality once nitrogen is released into coastal waters?