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Carl LoBue, Senior Marine Scientist, The Nature Conservancy Topic: The Value of Restoring Shellfish
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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, [email protected]
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
7
8
9
10
Con
ditio
n In
dex
0
1
2
3
4
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