TNC’s shellfish restoration efforts on Long Island NY:

Achievements, lessons learned, and next steps

Baird Symposium: The Future of Shellfish in RI

Nov 14, 2013

Carl LoBue, clobue@tnc.org

Ultimate objectiveRestore LI estuaries to thriving, healthy, naturally

productive, self-sustaining ecosystems that benefit people and nature

Key estuarine/coastal biogenic habitats

Why Shellfish?No clams 2 clams

4 clams

8 clams 16 clams

No clams 2 clams

4 clams

8 clams 16 clams

Great South Bay NY, circa 1976

Four main challenges to bay-wide clam recovery

Yum Clams!

Recruitment limitation

Water quality / clam food quality Predation

Effective, coordinated harvest management and enforcement

Fishing and predation mortality

“Whether the clams were abundant or scarce, commercial clammers on the Great South Bay have always been free to take as many as they want.” Newsday 12/22/2009

Increasing production of wild-born clams

Clam seed abundance and distribution

Clam seed abundance and distribution

2008 Brown Tide hits hard

GSB BT cell counts 2004-2012

Clam seed abundance and distribution

Jan0

4A

pr04

Jul0

4O

ct04

Jan0

5A

pr05

Jul0

5O

ct05

Jan0

6A

pr06

Jul0

6O

ct06

Jan0

7A

pr07

Jul0

7O

ct07

Jan0

8A

pr08

Jul0

8O

ct08

Jan0

9A

pr09

Jul0

9O

ct09

Jan1

0A

pr10

Jul1

0O

ct10

Jan1

15

6

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8

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10

Con

ditio

n In

dex

0

1

2

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Gonad R

ank

Y-MeanY-Mean

Condition Inde xGonad Rank

GSB - T ran splan t Site A

Clam condition and spawning 2004-2010

Conditions in GSB in 2011

Toxic algae bloom dashed hopes for 2012 scallop season

“Scallops Suffer Massive Die-Off: Red Tide May Be To Blame” EHS 10/23/12

Just a few weeks ago, baymen and shellfish experts were brimming with optimism about what was expected to be a banner bay scallop harvest when the season opens next month. Some pointed to the predictions as a sign that the local scallop population had finally gotten past the devastation wreaked by brown tides in the 1980s and 1990s.

This week, much of that optimism has evaporated.

Scientists from Long Island University.., said they found as much as 90 percent mortality rates in the mammoth “set” of bay scallops that they recorded at the start of the summer

Sources of reactive nitrogen to coastal waters

County land use data N-Load and ELM models quantify sources of Nitrogen loaded to LI bays

2008 Kinney and Valiela + 2010 USGS

33 GSB sub-watersheds

˜ 1M people live in the GSB groundwatershed

SWSD has ocean outfall

20% GW to Ocean

N loads to GSB from watershed (684,000 kg N / yr)

atm to land20%

atm to water0%

STPs1%

septic/ cesspool67%

agriculture1%

lawns7%

golf courses2%

Fire Island2%

Total N Loads to Great South Bay (908,000 kg N/Yr)

atm to land15%

atm to water25%

STPs1%

septic/ cesspool51%

agriculture0%

lawns5%

golf courses1%

Fire Island2%

Linking development to groundwater N, case study, Bicycle Path (Suffolk County 2011)

Other impacts of excessive algal growth from nitrogen pollution

LIS hypoxia

Algae symptoms are island-wide

Nitrogen enrichment impacts on seagrass from Butler (1999)

Thousands of acres of eelgrass have already disappeared

Eelgrass is Essential Fish Habitat

Nitrogen pollution impacts on saltmarshes

Images from Nature 10/2012

CAT scans of marsh roots: StableHealthy marsh

FailingImpacted marsh

Population gains still possible

Clam Seed Abundance and Distribution

New Sandy caused Inlet in eastern GSB

Increased water clarity

Lower dissolved nutrients

Increased circulation with ocean water

Transit of marine animals (fish and seals)

Positive response to new inlet / impacts not estuary wide

Unusually good growth near new inlet (Bellport Bay July 2013)

Defining “RESTORATION”

Future of shellfish in RI?

• Articulate goals (fishery vs production vs ecosystem)

• Address all major threats• Think ahead• Monitor / adapt• LI vs VCR• Commitment / Scale

Questions?

Development of the 2013 GSB brown tide