Transcript catsr.ite.gmu.edu

West and Rhode Rivers
Aquaculture System
- Amy Crockett - Amir Delsouz - John DeGregorio - Alan Muhealden - Daniel Streicher -
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Agenda
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Context Analysis
Problem Statement
Stakeholder Analysis
Statement of Need
Design Alternatives/Questions
Method of Analysis/Simulation
Project Plan/Budget
West and Rhode Rivers (WRR)
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Two sub-estuaries of the Chesapeake Bay
Contain 26 million cubic meters of water, average depth is 2 meters.
Watershed covers 78 square kilometers (J. Askvig et al. 2011)
Fairfax
Chesapeake
Bay
3
Rhode
West
Eutrophication Process
Excess Nutrients
Algae Bloom
Increased
Turbidity
SAV* Growth
Prevented
Hypoxic
Conditions
Aquatic
Species
Mortality
4
Data Source: West/Rhode Riverkeeper Report Card 2011
* SAV = Sub Aquatic Vegetation
Current Water Quality of WRR
INDICATOR
Water Clarity/
Secchi Depth
THRESHOLD
WEST RIVER
% of samples
RHODE RIVER
% of samples
GRADE
AVERAGE
>1m
30%
30%
D
> 5 mg/L
73%
92%
A-
< 0.65 mg/L
< 0.037 mg/L
47%
46%
C
Chlorophyll
< 6.2 μg/L
47%
40%
C-
Underwater
Grasses
> 1.2 km²
0%
0%
F
Dissolved
Oxygen
Nutrients (N/P)
Data Source: West/Rhode Riverkeeper Report Card 2011
5
Earlier Sponsorships
• Previous project established three alternatives to
decrease turbidity and increase SAV growth (Askvig
et al, 2010)
– Soft Shell Clams (Proposed Solution)
– Oysters
– Living Shoreline Restoration
6
Earlier Sponsorships Continued
• Pilot project by Smithsonian Environmental Research
Center Summer 2011
• All of the clams died: close to survivability limits
(Gedan, 2011)
• Oysters are known to be more resilient to varying
salinity and dissolved oxygen conditions, propose to
use oysters in order to improve water quality.
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Salinity Tolerance
y = -0.0002x + 16.096
R² = 0.0188
Salinity (1984 - 2011)
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Salinity Salinity
16
Clam Threshold
Shellfish Threshold
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Oyster Threshold
Linear (Salinity)
Salinity (ppt)
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10
8
6
4
2
0
O-84
J-87
A-90
J-93
O-95
J-98
Date (month/year)
Data Source: Maryland Department of Natural Resources
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M-01
D-03
S-06
J-09
Agenda
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Context Analysis
Problem Statement
Stakeholder Analysis
Statement of Need
Design Alternatives/Questions
Method of Analysis/Simulation
Project Plan/Budget
Problem Statement
The WRR has decreased water quality due to increased nutrients and
sediment from runoff and is exacerbated by loss of Sub-Aquatic Vegetation
(SAV) and other aquatic resources.
y = -3E-05x + 2.016
R² = 0.0685
Secchi Depth (1984 - 2011)
41.7%
Secchi
Depth
(2009)
2.5
Secchi Depth
2
Secchi Depth (m)
Secchi
Depth
(1989)
Percent
above
threshold
Threshold
Linear (Secchi Depth)
1.5
1
0.5
27.3%
0
O-84
14.4% Diff
J-87
A-90
J-93
O-95
J-98
M-01
Date (month/year)
Data Source: Maryland Department of Natural Resources
10
D-03
S-06
J-09
Agenda
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Context Analysis
Problem Statement
Stakeholder Analysis
Statement of Need
Design Alternatives/Questions
Method of Analysis/Simulation
Project Plan/Budget
Primary Stakeholders
1. West/Rhode Riverkeeper
2. Watermen
3. Maryland Department of Natural
Resources
4. Watershed Residents
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West and Rhode Riverkeeper
• Supports stopping pollution, enforcing
environmental law, promoting restoration, and
advocating for better environmental policy. (W/R
Riverkeeper, 2010)
• Monitors water quality
• Performs community outreach
Goal: Increase the water quality of W/R Rivers
13
Watermen
• Supports harvesting and sale of aquatic species
throughout the year.
• Estimated Salary: $8/hour ($18,000-36,000/year)
(Wieland, 2007)
• In the past two decades, working oystermen on the
bay have dropped to less than 500, from 6,000.
(New York Times, 2008)
Goal: Make a profit
14
Oyster Aquaculture
Maryland Oyster Harvest (Bushels)
Number of Oysters Harvested (Bushels)
16000000
14000000
12000000
Result of Overharvesting
10000000
Oyster Harvest (Bushels)
8000000
Presence of P. Marinus (Dermo)
6000000
4000000
2000000
0
1860
1880
1900
1920
1940
Year
1960
Source: Maryland Department of Natural Resources [8]
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1980
2000
2020
Maryland Dept. of Natural Resources
• Supports management of regional watershed, which
includes streams, coastal bays, and the Chesapeake
Bay.
• Provides regulation for shellfish harvesting
• Funds state hatcheries, provides aquaculture
training, and subsidizes loans
Goal: Environmental protection and increasing
employment through aquaculture
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Residents
• Supports recreational use of river and waterfront
property use.
• Provides public support for environmental cause.
• Also source of waste runoff and nutrient pollution.
(W/R Riverkeeper, 2010)
Goal: Support clean environment
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Stakeholder Relationship Diagram
Consumers
Pays Taxes
Aquaculture
Market
Market
Revenue
Waste
Runoff
Recreation
Market
Sales
Harvests Resources
Supplies Aquaculture
Watermen
West and
Rhode Rivers
Residents
Informs and
Promotes
Restoration
Supports and Funds
W/R
Riverkeeper
Supports and
Monitors
Pays Taxes
Supports
Conservation
Support
Aquaculture and
Regulates Licenses
18
MDDNR
Advocates Policy Change
Reinforcement Loop
Agenda
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Context Analysis
Problem Statement
Stakeholder Analysis
Statement of Need
Design Alternatives/Questions
Method of Analysis/Simulation
Project Plan/Budget
Statement of Need
There is a need for a system which will increase the secchi
depth of the West and Rhode River to at least 1 meter and will
be financially sustaining netting at least $36,000 per year in 5
years.
Source: MDDNR Water Quality Monitoring [1]
20
Win-Win Solution
• Oysters have potential to filter 190 liters of water per
day depending on environmental variables
• Implementation of oyster aquaculture in the WRR
will reduce turbidity
• Aquaculture opportunities for employment of
watermen
21
Originating Requirements
1.0 The system shall increase the secchi depth of the
WRR to at least 1 meter.
2.0 The system shall produce a profit of at least
$36,000 per year.
3.0 The system shall have a return on investment in
5 years.
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Scope
• Simulation of oyster growth rate within the varying
environment of the West and Rhode Rivers.
• Simulation of an oyster aquaculture business plan.
• Measurement of nutrient levels within the West and
Rhode Rivers, specifically the effect of Oysters as a
filtration source.
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Agenda
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Context Analysis
Problem Statement
Stakeholder Analysis
Statement of Need
Design Alternatives/Questions
Method of Analysis/Simulation
Project Plan/Budget
Design Alternatives
 Stage 1: Obtaining Oysters
 Larvae
 Seed
 Spat-on-Shell
 Stage 2: Final Product
 Half-Shell
 Shucked Oyster
 Stage 3: Selling Method
 Wholesale
 Direct Sell
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Oyster Lifecycle
Larvae
Data Source = Maryland Sea Grant, 2011
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Seed
Spat-on-Shell
Stage 1: Obtaining Oysters
Larvae
•Growth Method
-Remote Setting
•Type of Cultch
-Recycled Full Shell
•Number of Oysters on Each Shell
-Multiple
Data Source = Abel, 2011
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Stage 1: Obtaining Oysters
Seed
•Growth Method
-Nursery
•Type of Cultch
-Finely Crushed Shell
•Number of Oysters on Each Shell
-One
Data Source = Shockley, 2011
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Stage 1: Obtaining Oysters
Spat-On-Shell
•Growth Method
-N/A (Ready to be Placed in Cages)
•Type of Cultch
-Full Shell
•Number of Oysters on Each Shell
-One
Data Source = Congrove, 2009
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Stages 2 & 3
Final Product
Selling Method
 Shucked Oyster
 Direct Sale
– Ability to reuse shell
– Can be sold for canning
 Half Shell
–
–
–
–
Can be sold to restaurants
Only one oyster per shell
Can typically be sold for more
Not able to reuse shell
(Kallen, 2001) (MDNR,2011)
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– Requires a large investment of
time and energy by the seller
– One-on-one demonstrations
– Personal contact
– Internet sales
 Wholesale
– Selling the oysters in large
quantities to be retailed by
certified dealers
– Requires less investment of
time and energy by the
producer
Design Question: Cage Assemblies
Longline Culture System
B
C
3 subsystems:
• Mooring-Anchor System (A)
• Floatation System (B)
• Growing System (C)
31
A
(Merino, 1997)
Example of Floating Cages
(Webster, 2007)
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Cage Assemblies
FTension
FTension
FTension
FBuoyancy
mg
FTension
Buoyancy
mg
FTension
33
FTension
Agenda
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Context Analysis
Problem Statement
Stakeholder Analysis
Statement of Need
Design Alternatives/Questions
Method of Analysis/Simulation
Project Plan/Budget
Method of Analysis
Larvae
Seed
Spat on Shell
Alternatives
2DTMM
Growth
Model
Utility
Function
Business
Model
Simulation
Timeline
2DTMM = Two Dimensional Tidal Mixing Model (From Previous Project)
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Cost/Benefit
Analysis
Analysis
Growth Model
Stochastic Variable
Environmental
Variables
Mortality?
Stochastic Variable
Oyster
Biomass
Initial Conditions
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Biometric
Variables
Growth Rate
Oyster
Biomass
Final Output
Environmental Variables
Variable
Units
Stochastic
Range
Temperature
C elsius
Yes
1.5 - 31
Dissolved Oxygen
mg/L
Yes
1.0 - 16.5
Salinity
ppt
Yes
0.5 - 18
Total Suspended Solids
mg/L
No
N/A
Particulate Organic C arbon
mg/L
No
N/A
Total Nitrogen
mg/L
No
N/A
Total Phosphorus
mg/L
No
N/A
Biometric Variables
Variable
Unit
Stochastic
Value
Fraction Ingested
IF
No
0.12
Basal Metabolic
BM
No
0.008
Respiratory Fraction
RF
No
0.1
Assimilation Efficiency
α
No
0.77
Mortality Rate
β
No
0.0026
Source: C. Cerco/M. Noel 2007 [5] [19]
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Oyster Biomass
• Total weight of oysters measured in kg Carbon
• ΔO = (α * Fr * POC * IF(1-RF) * O) – (BM * O – β * O)
GROWTH
DEATH
Variable
Unit
Oyster Biomass
O
Particulate Organic C arbon
POC
Filtration Rate
FR
Fraction Ingested
IF
Basal Metabolic
BM
Respiratory Fraction
RF
Assimilation Efficiency
α
Mortality Rate
β
Source: C. Cerco/M. Noel 2007 [5] [19]
38
Growth Model Assumptions
• The water column being modeled is thoroughly
mixed.
• Sink amounts will be placed within legal boundaries.
• Sink rates will be uniform for the entire cell.
• Wind shear will be negligible.
• Tide flow into each cell occurs instantaneously.
• Environmental variable concentrations are assumed
to be uniform throughout each cell.
39
Growth Model Validation
• Method A – Scenario Simulation
– Compare model filtration rate with real oyster
filtration rate within different scenarios.
• Ex. Compare a 3 year cycle of oyster growth to
fully grown oysters and measure filtration
• Method B – Pilot Study
– Funded by SERC
– Measure Oyster Growth for
a year, verify with model.
40
Notional Oyster Growth
2000
1800
Oyster Biomass
1600
Oyster Biomass (g C)
1400
1200
1000
800
600
400
200
0
0
50
100
150
200
Time (Days)
41
250
300
350
2D Tidal Mixing Model
Oyster
Biomass
Cell 1
Cell 2
Cell 3
Cell 4
Cell 5
Cell 6
Cell 7
Cell 8
Cell 9
Tidal Flow
Cell Attributes
N,P,TSS Load
Initial Conditions
N,P,TSS
Removed
Final Output
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Cell Attributes
Cell
Surface Area (m^2)
Average Depth (m)
Volume (m^3)
1
3,099,012
3.05
9,445,789
2
3,024,895
2.44
7,375,904
3
2,322,522
2.13
4,955,333
4
1,251,301
1.22
1,525,586
5
4,211,924
2.75
11,582,791
6
4,603,933
2.13
9,822,951
7
2,526,922
1.83
4,621,235
8
1,493,339
1.22
1,820,679
9
1,390,849
1.17
1,627,293
Total Volume
52,777,561
Source: J. Askvig et al. 2011 [1]
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Tidal Flow
Vn= Volume of Cell n
Tn= Tide volume of Cell n
Nn= Nitrogen concentration of Cell n
Bay to Cell 1:
F = River volume
Bn = Bay Concentration of Nitrogen
Rn = River Concentration of Nitrogen
N1= (N1·V1+ Bn·T1) / (V1+T1)
Cell 1 to Cell 2: N2= (N2·V2+ N1·T2) / (V2+T2)
N1= (N1· (V1+ T1 ) + Bn·T1 - N1·T2) / (V1+T1)
Cell 2 to Cell 3: N3= (N3·V3+ N2·T3) / (V3+T3)
N2= (N2· (V2+ T2 ) + N1·T3 - N2·T3) / (V2+T2)
V1
Ve
V0
N1= (N1· (V1+ T1 ) + Bn·T3 - N1·T3) / (V1+T1)
Cell 3 to Cell 4:
N4= (N4·V4+ N3·T4) / (V4+T4)
N3= (N3· (V3+ T3 ) + N3·T4 - N3·T4) / (V3+T3)
N2= (N2· (V2+ T2 ) + N1·T3 - N2·T4) / (V2+T2)
Source: VIMS, 1993
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V0+Ve+Vt1 = V2
Assume complete mixing and a new
N2 mg/L
Oyster Clearance Rates
•
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•
•
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•
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Filtration Rate (FR) = Frmax*F(S)*F(DO)*F(T)*F(TSS)
Frmax = 0.55 m³ g
F(S) = 0.5*(1 + tanh(S – 7.5))
F(DO) = (1+exp(3.67*(1-DO)))
F(T) = exp(-0.015*(T – 27)²)
F(TSS) = 0.1 when TSS < 5 mg/L
1.0 when 5 mg/L < TSS < 25 mg/L
0.2 when 25 mg/L < TSS < 100 mg/L
0.1 when TSS > 100 mg/L
Future Growth Simulation Work
4.2.4 Build Growth Simulation
4.2.6 Validate Model
4.2.7 Run Monte Carlo Simulation
5.2 Analyze Model
• Assess Survivability Probability
• Verify Model Growth Rate
5.2.1 Conduct Sensitivity Analysis
• Environmental Variable Analysis
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Business Model
t < 5 Yrs
Time
Start-up Cost/
Loan Payment
Survival?
t > 5 Yrs
t < 3 Yrs
+
No
I
Cost
Time
End
No
Growth
Model
t >= 3 Yrs
Revenue
Plant oysters for next
season
47
Yes
Yes
Profit?
t+1
Business Model Variables
Variables
48
Directly Dependent on
Environmental Variables
Oyster price from hatchery
No
Transportation Cost
No
Maintenance Cost
No
Storage/Building Cost
No
Shell Cost
No
Equipment Cost
No
Oyster Selling Price
No
Labor Cost
No
Salt for Remote Setting
Yes
Heat for Remote Setting
Yes
Number of oysters to plant
for next season
Yes
Business Model Assumptions
• Certain equipment will need to be replaced on 3,5,
and 10 year basis
• Receive MDNR loan
– 5 year loan
– Interest only first 3 years (3% yearly)
– 40% forgiven beginning of fourth year if in good
standing with MDNR
– Last 2 years principle payments with 5% yearly
interest
49
Design of Experiment
Design Alternatives
Stage Obtained
Final Product
Shucked
Utilities
Method of Sale
Direct
Whole
Larvae
Half Shell
Direct
Whole
Shucked
Direct
Whole
Seed
Half Shell
Direct
Whole
Shucked
Direct
Whole
Spat-on-Shell
Half Shell
Direct
Whole
50
Profit
Availability of Shell
Availability of Oyster
Notional Cost Input to Model
Larvae
Seed Cost
Cost ($)
Spat-OnShell
Years
51
Notional Profit from Wholesale
Larvae to Shuck
Seed to Shuck
Profit ($)
Seed to Half Shell
Spat-on-Shell to Shuck
Spat-on-Shell to Half Shell
Years
52
Implementation Risks and Mitigation
Implementation Risks
Mitigation
• Large differences in revenue between
years (Due to variability of environmental
conditions, disease, variance of prices)
• Determine a cycle and build in funds to
help smooth revenue netted over time
• Poaching of oysters
• Watermen patrol area
• Community Stewardship
• Floating Cages
• Low Salinity
• Place remote setting where low salinity
only occurs less than every ten years
(MDNR, 2011)
53
Future Business Simulation Work
3.2.1 Determine Value Hierarchy Weights
•
In conjunction with watermen and MDNR
4.3.3 Design Business Simulation
4.3.4 Code Business Simulation
4.3.5 Validate Model
•
Compare results with University of Maryland Extension aquaculture
experts
5.1.1 Analyze Results
• Probability of total business failure
• Number of oysters needed to be profitable
5.1.2 Conduct Sensitivity Analysis
54
Value Hierarchy
Aquaculture System
Objective Function
Maximize Stakeholder
Approval
Maximize Sustainability
0.33
0.30
0.37
Public Approval
Return on Investment
0.40
0.50
Commercial Value
Availability of Shell
Decrease Phosphorus
0.60
0.30
0.25
Availability of Oyster
from Hatchery
Decrease Nitrogen
Weights determined in conjunction with
W/R Riverkeeper VIMS and SERC
(Askvig et al, 2010)
55
Maximize Water Quality
0.20
Decrease Sediment
0.50
Decrease Nutrients
0.50
0.25
Agenda
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•
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Context Analysis
Problem Statement
Stakeholder Analysis
Statement of Need
Design Alternatives/Questions
Method of Analysis/Simulation
Project Plan/Budget
Work Breakdown Structure (WBS)
WRR
Aquaculture
System
1.0 Management
2.0 Research
4.0 Modeling
5.0 Analysis
6.0 Report
1.1Work
Breakdown
Structure
2.1 Concept of
Operations
3.1
Requirements
4.1 Oyster
Growth Model
5.1 Trade-off
Analysis
6.1 Papers
1.1 Weekly
Reports
2.2 Oyster
3.2 Value
Hierarchy
4.2 Business
Model
5.2 Growth
Model Analysis
6.2 PowerPoint
Presentations
1.2 Meeting
Minutes
2.3 Legal
4.3 VIMS Model
5.3 Cost-Benefit
Analysis
6.3 Posters
1.3 Budget
2.4 Environment
2.5 Business
2.6 Field
Research
57
3.0 Design
5.4 Long-Term
Plan
Project Schedule
September
October
November December
January
February
March
April
Management
Scope
Requirements
Design Alternatives
Model Research
Paper 1
Utility Weights
Paper 2
Model V/V
Final
Model Building
Analysis
Final Proposal
Abstract
Poster
Paper
Competition Prep
58
May
Earned Value Management
100000
Planned Cost = $37,008
Actual Cost = $25,050
Earned Value = $39,720
CPI = 1.48
SPI = .93
90000
80000
70000
Cost Spent ($)
60000
Planned
Value
Actual Cost
50000
Earned Value
40000
30000
20000
10000
0
0
5
10
15
20
Week Number
59
25
30
35
40
Project Plan Risks and Mitigation
Project Plan Risks
Mitigation
• Merging growth and business model
• Determine interface requirements
• Begin initial merge as soon as possible
• Gathering accurate data for the business
model
• Start collecting data as soon as possible
• Talk to current aquaculture specialists and
businesses about data
60
Questions?
61
References
[1] J. Askvig et al., West and Rhode River Turbidity Reduction Project: Preliminary Evaluation. George Mason University, VA, 2011.
[2] I. Urbina, Nov 2008, http://www.nytimes.com/2008/11/29/us/29poultry.html?partner=rss&emc=rss. Accessed October 20, 2011.
[3] MDDNR, Apr 2009, http://www.dnr.state.md.us/dnrnews/infocus/oysters.asp . Accessed September 15, 2011.
[4] MDDNR, Apr 2009, http://www.dnr.state.md.us/fisheries/oysters/industry/funding.asp. Accessed September 15, 2011.
[5]C. Cerco and M. Noel, Can Oyster Restoration Reverse Cultural Eutrophication in Chesapeake Bay?. US Army Engineer Research and
Development Center. Vicksburg, Ms, 2007.
[6] Dr. Donohue, verbal communication
[7] West/Rhode Riverkeeper, 2010, http://www.westrhoderiverkeeper.org/index.php/about-us/riverkeeper-program.html. Accessed
September 1, 2011.
[8] MDNR Report, http://www.dnr.state.md.us/fisheries/oysters/mtgs/111907/JudyOysHarvestsandRepletionProgram.pdf. Accessed
October 10, 2011
[9] R. Wieland, The Feasibility for Sustainable Provision of Hatchery Products for Oyster Aquaculture in the Chesapeake Bay. Main Street
Economics, Trappe, Md, 2007.
[10] Horn Point Oyster Hatchery, 2011, http://www.hpl.umces.edu/hatchery/ . Accessed September 10, 2011.
[11] Environmental Cooperative Science Center, 2008, http://ecsc.famu.edu/summaryiss.html. Accessed September 17, 2011.
[12] Coast Seafoods Company, 2011, http://www.coastseafoods.com/triploid_oysters.html. Accessed September 12, 2011.
[13] R. Kallen et al., Small Scale Oyster Farming for Chesapeake Watermen. TerrAqua Environmental Science Policy, LLC. September 2001,
http://www.terraqua.org/SI_oyster_biz_plan.pdf
[14] L. Allen, Nov 2010, http://www.cecilwhig.com/business/article_097d6b04-f803-11df-ac69-001cc4c002e0.html. Accessed September
12, 2011.
.
62
References
[15] R. Wieland, The Feasibility for Sustainable Provision of Hatchery Products for Oyster Aquaculture in the Chesapeake Bay. Main
Street Economics, Trappe, Md, 2007. http://www.mainstreeteconomics.com/docs/MSERCfin.pdf
[16] J. Davidsburg, Aug 2011, http://www.dnr.state.md.us/fisheries/news/story.asp?story_id=181. Accessed September 12, 2011
[17] MDDNR Data Hub, 2011, http://www.chesapeakebay.net/data/index.htm
[18] West/Rhode Riverkeeper, Oct 2009, http://www.westrhoderiverkeeper.org/images/stories/PDF/West_River_Tech_Memo.pdf.
Accessed September 3, 2011.
[19] C. Cerco and M.Noel, Evaluating Ecosystem Effects of Oyster Restoration in Chesapeake Bay. Sep 2005,
http://www.dnr.state.md.us/irc/docs/00015769.pdf
[20] G. Merino, Considerations for Longline Culture Systems Design: Scallops production. Universidad Catolica del Norte. Chile.
1997
[21] M. Parker et al., Economics of Remote Setting in Maryland: A Spreadsheet for Cost Analysis. Maryland Sea Grant Extension,
Md, 2011.
[22] Oyster Restoration Partnership, 2011, http://www.oysterrecovery.org/Content/ContentDisplay.aspx?ContentID=118.
Accessed September 12, 2011.
[22] K. Gedan, Smithsonian Environmental Research Center, Presentation, November 2011.
[23] D. Webster. Oyster Aquaculture Production. University of Maryland, MD, 2007.
[24] Maryland Sea Grant, http://www.mdsg.umd.edu/issues/chesapeake/oysters/garden/guide/seed/. Accessed November 29,
2011.
63
Appendix I - Our Field Data
Station
Depth (feet)
w6
w20
AVG
Specific
Conductance(uS)
Temp (C)
Dissolved Oxygen
%
DO mg/L
salinity (ppt)
2
23.5
5.78
3.13
91
7.6
8.2
4
23.6
5.8
3.14
90.7
7.62
8.25
6
23.7
5.85
3.17
90.3
7.51
8.32
8
23.7
5.85
3.17
92.1
7.63
8.34
10
23.3
5.84
3.17
91.1
7.63
8.35
12
23.1
5.78
3.13
93.6
7.9
8.37
2
22.9
5.88
3.19
91.4
7.65
8.2
4
23
5.89
3.2
91.4
7.67
8.16
6
23
5.91
3.12
87.6
7.23
8.14
8
23
5.92
3.22
86.1
7.23
8.11
10
23
5.91
3.22
86.6
7.13
8.07
12
22.9
5.95
3.23
82.9
6.99
8.03
23.23
5.86
3.17
89.57
7.48
8.21
Taken September 16, 2011
64
pH
Appendix I - Our Field Data
West/Rhode River Sample 10/14/11
Station
W06
W20
CYC
65
Temp (°C)
Depth (ft)
Salinity (ppt)
DO (%)
DO (mg/L)
pH
SC (μS)
2
19.7
4.02
99
8.83
8.3
N/A
4
19.71
4.02
97.1
8.67
8.28
N/A
6
19.71
4.05
96.4
8.61
8.27
N/A
8
19.71
4.04
96
8.56
8.26
N/A
10
19.7
4.34
95
8.38
8.16
N/A
12
N/A
N/A
N/A
N/A
N/A
N/A
2
19.75
3.85
99.1
8.82
8.39
N/A
4
19.74
3.86
97.4
8.7
8.35
N/A
6
19.74
3.85
97.1
8.68
8.34
N/A
8
19.74
3.85
97.1
8.67
8.33
N/A
10
19.74
3.86
97.1
8.68
8.32
N/A
12
N/A
N/A
N/A
N/A
N/A
N/A
1
20.03
4.17
90.3
8.05
8.66
N/A
6
19.88
4.23
90.2
7.94
8.63
N/A
Average
19.76
4.01
95.98
8.55
8.36
N/A
Std
0.10
0.17
2.90
0.28
0.15
N/A
Appendix II - Charts
y = -4E-05x + 2.0926
R² = 0.0803
Rhode River Secci Depth (1984 - 2011)
2.5
Secci Depth
Threshold
2
Secci Depth (m)
Linear (Secci Depth)
1.5
1
0.5
0
October 1984
July 1987
April 1990
January 1993 October 1995
July 1998
Date (month/year)
66
March 2001 December 2003September 2006 June 2009
Appendix II - Charts
2010 VIMS Model – Secchi Depth Improvement
67
Appendix II - Charts
Spat-on-Shell
Cost
Ready to be
placed in cages
Seed
Larvae
3–5
7 – 10
Time (days)
68
Appendix III - Definitions
Turbidity
 Having sediment and/or foreign particles stirred up or suspended in
water (haziness)
 Contributions to turbidity in WRR
 Excess nutrients and sediments that flow into the rivers through
the tide
 Run off from surrounding land (Local residents, farms,
construction)
 Suspended Solids (ie: algae)
 Reduce dissolved oxygen level, killing off other life in river.
69
Appendix III - Definitions
Salinity
 Salt content of the water (measured in parts per thousand (ppt))
 Salt water flows into the Chesapeake from the Atlantic Ocean.
 Fresh water flows into the Chesapeake from the Susquehanna River,
creeks and rain.
 Eastern Oysters (Crassostrea virginica) require at least 7.5 ppt to be
filtering effectively [2]
70
Appendix III - Definitions
Shucked vs. Half Shell
71
Shucked
Half Shell
• Ability to reuse shell
• Can be sold for canning
• Multiple oyster larvae
attach to one shell
• Can be sold to restaurants
• Only one oyster per shell
• Can typically be sold for
more
• Shell is lost
• Requires more marketing
Appendix IV – Etc.
Design Alternatives
72
Growth
Method
Type of
Cultch
Number of Final
oysters on Product
each shell
Growth
Process
Risks
Larvae
Remote
Setting
Recycled
full shell
Multiple
Shucked
oyster
Hatchery
to land to
cages
Availability
of shell
Seed
Nursery
Finely
crushed
shell
One
Half shell,
shucked
Hatchery
to floats to
cages
Spat-onShell
N/A
Full shell
One
Half shell,
shucked
Hatchery
to cages
Availability
Appendix IV – Etc.
Cage Equations
• Floatation = Dry body weight * [1 – (δfluid/δbody)]
• Resistance force = ½ * Cd * A * δ * v2
• Rope Sizing
– Length: n = j * h
– Tension: Tm-a = (Th2 + Tv2)0.5
– Rope Diameter: d = (Tmax * Fs)0.5 / Cr
• Buoy Sizing
– Vb = [W / [(δsw – δb) * g]] * Fs
• Anchor System Sizing
– Vanchor = Wdry / δanchor * g
– Wsub = (Tm-a * cos Φ / μ) + Tm-a * sin Φ
73
Appendix IV – Etc.
Cage Assemblies Longline Culture System
• Mooring-Anchor System
– Stabilizes the system against the effects of both vertical
and horizontal stresses
• Floatation System
– Maintains suspension of the culture system
• Growing System
– Used to contain and grow oysters
• Design Principles
– Buoyancy Force
• Floatation or Gravity Force on an Immersed Body
– Resistance Force
– Tension between all lines
74
nsgd.gso.uri.edu/hawau/hawauw97002/hawauw97002_part6.pdf
Example of Floating Cages
(Webster, 2007)
75