1. Evaluation of shellfish aquaculture and nutrient removal and credit trading in Long Island Sound
Suzanne Bricker NOAA National Ocean Service
Joao Ferreira IMAR
Katharine Wellman Northern Economics
Gary Wikfors NOAA National Marine Fisheries Service
Mark Tedesco EPA Long Island Sound Study
Julie Rose NOAA National Marine Fisheries Service
Bob Rheault East Coast Shellfish Growers Association
Robin Landeck Miller HydroQual
Paul Mankiewicz The Gaia Institute
Estuarine & Coastal Sciences Association: ECSA47 Symposium
Figueira da Foz, Portugal
September 14-19, 2010

2. Long Island Sound: Background
New York
Connecticut
Size: 3,259 km2
Tide: 2 m in west, 1 m in east
Residence time: 2-3 months
Highly developed watershed
Population: 4.9 x 106 total, 1,508 people/km2
2/3 freshwater inflow from Connecticut River
The Long Island Sound Study names 4 major water quality issues being addressed by government agencies, environmental groups, universities and the private sector:
Nutrients and hypoxia - eutrophication
Toxic Contaminants and pollution
Pathogens
Floatable debris

3. EPA Regional Ecosystem Services Program– Eutrophication and shellfish aquaculture
Two year project, EPA funded, focus on Long Island Sound and Great Bay/Piscataqua region;
Research groups from NOAA, EPA, HydroQual Inc., Longline Environment Ltd., Northern Economics, Shellfish Environmental Services;
Conduct a comparative study on the bioextraction potential of shellfish, and its contribution to ecosystem services;
Species: Eastern oyster, Northern quahog, ribbed mussel;
For Long Island Sound (major case study): combine watershed models, detailed water quality models (SWEM), EcoWin2000, FARM, and economic models.

4. LIS Eutrophication Impacts
Loss of eelgrass from historic range
Hypoxia
Species shifts
(Picture or explanation?)

5. NEEA/ASSETS Results: LIS Highly Eutrophic
Since early 1990s:
Nuisance/toxic blooms improved
Macroalgae improved
Chl no change
SAV no change
DO worsened
Bricker et al. 2007, Nutrient enrichment in
the nation`s estuaries, A decade of change. National Estuarine Europhication Assessment Update.

6. *Total Maximum Daily Load
Potential Resolution of Nutrient issues: Long Island Sound TMDL* (Approved by EPA April 2001)
In-basin Nitrogen Reduction Goal
58.5% by 2014
10% reduction to urban and agricultural runoff
59-64% reduction to point sources
Allows “Trading” of nutrient credits
Out-of-basin Actions
Out of State Sources (10% reduction to runoff, 25% reduction to point sources)
Atmospheric Deposition (Clean Air Act reductions)
Alternatives to nutrient control
Biomass harvesting
Periodic Revision (Adaptive Management)
Evaluation in 2008
*Total Maximum Daily Load

7. December 3-4, 2009 at UConn Stamford
Potential Resolution of Nutrient issues: nutrient bioextraction considered for LIS
Longtime nitrogen management focus has been point sources (i.e. wastewater treatment plant upgrades)
Growing recognition that non-point source pollution is also a substantial (more difficult) problem
Nutrient bioextraction can also address legacy pollution in the water column and sediments
International Workshop on Bioextractive Technologies for Nutrient Remediation
December 3-4, 2009 at UConn Stamford

8. How does bioextraction work?
Cultivation and harvest of shellfish and macroalgae
Nutrients are taken up directly (seaweed) or indirectly (shellfish, via plankton, organic detritus)
Removal of biomass removes nutrients from the ecosystem
Removal of 1ary eutrophication symptoms reduces 2ary symptoms by (i) improving water clarity, restoring SAV; (ii) limiting D.O. loss from decomposition of organic matter
Shellfish farmers can negotiate nutrient credits to offset loading fom land, and be included in the trading program

9. Harvest – Bottom Culture State Approved Restricted Prohibited Total
Scope of shellfish aquaculture: American Oyster (Crassostrea virginica), Northern Quahog clam (Mercenaria mercenaria)
Harvest – Bottom Culture
Shellfish lease area
20 kT
State Approved Restricted Prohibited Total
as % total area 103 acres NY CT
NY/CT
27 kT NY
only
Approved for CT includes conditionally approved, for
NY Approved is represented by Certified and Restricted is represented by Seasonal rating.
Prohibited (CT) and Uncertified (NY) are considered equal.
Area which appears to be actually farmed is under 1% of approved area
On the basis of a yield of 10 tonnes ha-1 (1 kg m-2), the reported harvest of ~17,000 tonnes (37 million lb) would correspond to 17 km2, i.e. ~4200 acres

10. The REServ approach Economic model
Millennium Ecosystem Assessment Framework
Field measurements
Farm-scale modelling
FARM model
Catchment model
SPARROW, Watershed Runoff Modelling
System- and local-scale ecological modelling
E2K, FARM, ASSETS
System-scale ecological modelling
SWEM, E2K, ASSETS
Transport model
SWEM
Public participation
Individual growth models for cultivated species
Ribbed mussel
In situ and lab experiments

11. Change in dissolved oxygen through the use of IMTA
Preliminary simulations of biomass harvesting show substantial DO improvements
Phase 3 & 4 TMDL: N & Corg
4.0
3.0
2.0
1.0
0.0
With shellfish
and seaweeds
Minimum D.O (mg L-1)
+4.0
+2.0
0.0
-2.0
-4.0
System-Wide Eutrophication model (SWEM)
HydroQual, 2009.
Model year simulation: 1988
Delta min.D.O (mg L-1)
Change in dissolved oxygen through the use of IMTA

12. Data Drivers for simulated farm
Simulated farm location is within approved lease areas
Data for Station 09 for 2008
Thanks to Matt Lyman of CTDEP
Simulated farm location from CTDEP aquaculture bottom lease maps and CTDEP data for station 09 for drivers of FARM

13. Data Drivers for FARM model application Station 09 for 2008
TSS = PIM + POM
POM = algal POM + detrital POM

14. Preliminary FARM model results
N removal is net, and equivalent to nutrient removal for about 13.5 thousand PEQ. About 1000 farms to remove total load, area would be less than 3%
Total N load to LIS = 50 x103 t y-1

15. Summary and Conclusions
Biomass harvesting –
promising solution to nutrient issues
complementary to land-based nutrient load reductions
provides shellfish product, income for shellfish farmers
caveat: marine spatial planning
Significance to LIS nutrient budget not known but -
45 tons N removed in one 10 hectare farm (PEQ 13,600)
Shellfish cultivation in 3% LIS area would remove equivalent of present N load
If significant, will shellfish farmers become part of the LIS nutrient trading program?
Stay tuned
Try the models yourself:
FARM
ASSETS