west and rhode rivers aquaculture system

1

West and Rhode Rivers Aquaculture System- Amy Crockett - Amir Delsouz - John DeGregorio - Alan Muhealden - Daniel Streicher -

2

Agenda• Context Analysis• Problem Statement• Stakeholder Analysis• Statement of Need• Design Alternatives/Questions• Method of Analysis/Simulation• Project Plan/Budget

3

West and Rhode Rivers (WRR)

Context Analysis

• 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

West

Rhode

Chesapeake Bay

4

Eutrophication Process

Context Analysis

Excess Nutrients

Algae Bloom

Increased Turbidity

SAV* Growth Prevented

Hypoxic Conditions

Data Source: West/Rhode Riverkeeper Report Card 2011

Aquatic Species

Mortality* SAV = Sub Aquatic Vegetation

5

Current Water Quality of WRR

Context Analysis

INDICATOR THRESHOLD WEST RIVER% of samples

RHODE RIVER% of samples

GRADE AVERAGE

Water Clarity/ Secchi Depth

> 1 m 30% 30% D

Dissolved Oxygen

> 5 mg/L 73% 92% A -

Nutrients (N/P) < 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

Data Source: West/Rhode Riverkeeper Report Card 2011

6 Context Analysis

• 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

Earlier Sponsorships

7

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.

Context Analysis

8 Context Analysis

Salinity Tolerance

Data Source: Maryland Department of Natural Resources

O-84 J-87 A-90 J-93 O-95 J-98 M-01 D-03 S-06 J-090

2

4

6

8

10

12

14

16

18

f(x) = NaN x + NaNR² = 0 Salinity (1984 - 2011)

Salinity

Linear (Salinity)

Shellfish Threshold

Date (month/year)

Salin

ity (p

pt)

Salinity

Clam Threshold

Oyster Threshold

9


10

Problem Statement

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.

O-84 J-87 A-90 J-93 O-95 J-98 M-01 D-03 S-06 J-090

0.5

1

1.5

2

2.5

f(x) = − 3.3222664173928E-05 x + 2.01599500665494R² = 0.0685078355680124

Secchi Depth (1984 - 2011)

Secchi Depth

Linear (Secchi Depth)

Threshold

Date (month/year)

Secc

hi D

epth

(m)

Secchi Depth(1989)

Percent above

threshold

41.7%

Secchi Depth(2009)

27.3%

Data Source: Maryland Department of Natural Resources14.4% Diff

11


12

Primary Stakeholders

Stakeholder Analysis

1. West/Rhode Riverkeeper2. Watermen3. Maryland Department of Natural Resources4. Watershed Residents

13

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 outreachGoal: Increase the water quality of W/R Rivers

14

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

15

Oyster Aquaculture


0

2000000

4000000

6000000

8000000

10000000

12000000

14000000

16000000

1860 1880 1900 1920 1940 1960 1980 2000 2020

Num

ber o

f Oys

ters

Har

vest

ed (

Bush

els)

Year

Maryland Oyster Harvest (Bushels)

Oyster Harvest (Bushels)Result of Overharvesting

Presence of P. Marinus (Dermo)

Source: Maryland Department of Natural Resources [8]

16

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 loansGoal: Environmental protection and increasing employment through aquaculture

17

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

18

Stakeholder Relationship Diagram


West and Rhode Rivers

Residents

Watermen

W/R Riverkeeper

MDDNR

Pays Taxes

Support Aquaculture and Regulates Licenses

Informs and Promotes Restoration

Supports and Funds

Advocates Policy Change

Pays Taxes

Harvests Resources

Supports Conservation

Aquaculture Market

Market Sales

Market Revenue

Consumers

Supports and Monitors

Waste Runoff Recreation

Supplies Aquaculture

Reinforcement Loop

19


20

Statement of Need

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]

21

Win-Win Solution

Statement of Need

• 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

22

Originating Requirements

Statement of Need

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.

23

Scope

Statement of Need

• 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.

24


25

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

Design Alternatives

26

Oyster Lifecycle

Design Alternatives

Data Source = Maryland Sea Grant, 2011

Larvae Seed

Spat-on-Shell

27

Larvae

Design Alternatives

Data Source = Abel, 2011

•Growth Method-Remote Setting

•Type of Cultch-Recycled Full Shell

•Number of Oysters on Each Shell-Multiple

Stage 1: Obtaining Oysters

28

Seed

Design Alternatives

Data Source = Shockley, 2011

•Growth Method-Nursery

•Type of Cultch-Finely Crushed Shell

•Number of Oysters on Each Shell-One


29

Spat-On-Shell

Design Alternatives

Data Source = Congrove, 2009

•Growth Method-N/A (Ready to be Placed in Cages)

•Type of Cultch-Full Shell

•Number of Oysters on Each Shell-One


30

Final Product Shucked Oyster

– 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

Selling Method Direct Sale

– 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 (Kallen, 2001) (MDNR,2011)

Design Alternatives

Stages 2 & 3

31

Design Question: Cage Assemblies

Design Questions

(Merino, 1997)3 subsystems:• Mooring-Anchor System (A)• Floatation System (B)• Growing System (C)

A

B

C

Longline Culture System

32

Example of Floating Cages

Design Questions

(Webster, 2007)

33

Cage Assemblies

Design Questions

Buoyancy

mg

FTension

FTension

FBuoyancy FTension

FTensionmg

FTension FTension

34


35

Method of Analysis

Method of Analysis

2DTMM

Growth Model

Business Model

Utility Function

Cost/Benefit Analysis

2DTMM = Two Dimensional Tidal Mixing Model (From Previous Project)

Larvae

Seed

Spat on Shell

Alternatives Simulation AnalysisTimeline

36

Growth Model

Method of Analysis

Oyster Biomass

Initial Conditions

Environmental Variables

Biometric Variables

Mortality?

Growth Rate Oyster Biomass

Final Output

Stochastic Variable

Stochastic Variable

37


Method of Analysis

Variable Units Stochastic RangeTemperature Celsius Yes 1.5 - 31

Dissolved Oxygen mg/L Yes 1.0 - 16.5Salinity ppt Yes 0.5 - 18

Total Suspended Solids mg/L No N/AParticulate Organic Carbon mg/L No N/A

Total Nitrogen mg/L No N/ATotal Phosphorus mg/L No N/A

Biometric VariablesVariable Unit Stochastic Value

Fraction I ngested I F No 0.12Basal Metabolic BM No 0.008

Respiratory Fraction RF No 0.1Assimilation Efficiency α No 0.77

Mortality Rate β No 0.0026Source: C. Cerco/M. Noel 2007 [5] [19]

38

Oyster Biomass

Method of Analysis

Source: C. Cerco/M. Noel 2007 [5] [19]

• Total weight of oysters measured in kg Carbon• ΔO = (α * Fr * POC * IF(1-RF) * O) – (BM * O – β * O)

GROWTH DEATH

Variable UnitOyster Biomass O

Particulate Organic Carbon POCFiltration Rate FR

Fraction I ngested IFBasal Metabolic BM

Respiratory Fraction RFAssimilation Efficiency α

Mortality Rate β

39

Growth Model Assumptions

Method of Analysis

• 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.

40

Growth Model Validation

Method of Analysis

• 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.

41

Notional Oyster Growth

Simulation

0 50 100 150 200 250 300 3500

200

400

600

800

1000

1200

1400

1600

1800

2000

Oyster Biomass

Time (Days)

Oys

ter B

iom

ass (

g C)

42

2D Tidal Mixing Model

Method of Analysis

Oyster Biomass

Tidal Flow

Initial Conditions

Cell 1

N,P,TSS Removed

Final Output

Cell Attributes

N,P,TSS Load

Cell 2 Cell 3

Cell 4 Cell 5 Cell 6

Cell 7 Cell 8 Cell 9

43

Cell Attributes

Method of Analysis

Cell Surface Area (m^2) Average Depth (m) Volume (m^3)1 3,099,012 3.05 9,445,7892 3,024,895 2.44 7,375,9043 2,322,522 2.13 4,955,3334 1,251,301 1.22 1,525,5865 4,211,924 2.75 11,582,7916 4,603,933 2.13 9,822,9517 2,526,922 1.83 4,621,2358 1,493,339 1.22 1,820,6799 1,390,849 1.17 1,627,293

Total Volume 52,777,561

Source: J. Askvig et al. 2011 [1]

44

Tidal Flow

Method of Analysis

Vn= Volume of Cell n F = River volumeTn= Tide volume of Cell n Bn = Bay Concentration of NitrogenNn= Nitrogen concentration of Cell n Rn = River Concentration of Nitrogen

N1= (N1· (V1+ T1 ) + Bn·T3 - N1·T3) / (V1+T1)

Bay to Cell 1: 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)


N2= (N2· (V2+ T2 ) + N1·T3 - N2·T3) / (V2+T2)


N3= (N3· (V3+ T3 ) + N3·T4 - N3·T4) / (V3+T3)

N2= (N2· (V2+ T2 ) + N1·T3 - N2·T4) / (V2+T2)

Source: VIMS, 1993

V0+Ve+Vt1 = V2

Assume complete mixing and a new N2 mg/L

V0

V1

Ve

45

Oyster Clearance Rates • 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/L0.2 when 25 mg/L < TSS < 100 mg/L0.1 when TSS > 100 mg/L

Method of Analysis

46

Future Growth Simulation Work

Method of Analysis

4.2.4 Build Growth Simulation4.2.6 Validate Model4.2.7 Run Monte Carlo Simulation5.2 Analyze Model

• Assess Survivability Probability• Verify Model Growth Rate

5.2.1 Conduct Sensitivity Analysis• Environmental Variable Analysis

47

Growth Model

Start-up Cost/ Loan Payment

Cost

RevenueI Time

Survival?

Profit?

Time

End

t < 5 Yrs

t > 5 Yrs t < 3 Yrs

t >= 3 Yrs

Yes

Yes

No

No

Plant oysters for next season

Business Model

+

t + 1

Method of Analysis

48

Business Model VariablesVariables Directly Dependent on


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

Method of Analysis

49

Business Model Assumptions

Method of Analysis

• 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

50

Design Alternatives Utilities

Stage Obtained Final Product Method of Sale Profit Availability of Shell Availability of Oyster

Larvae

Shucked Direct

Whole

Half Shell Direct

Whole

Seed

Shucked Direct

Whole

Half Shell Direct

Whole

Spat-on-Shell

Shucked Direct

Whole

Half Shell Direct

Whole

Design of Experiment

Method of Analysis

51

Notional Cost Input to Model

Simulation

Larvae

Seed Cost

Spat-On-Shell

Cost

($)

Years

52

Notional Profit from Wholesale

Simulation

Larvae to Shuck

Seed to Shuck

Seed to Half Shell

Spat-on-Shell to Shuck

Spat-on-Shell to Half Shell

Years

Profi

t ($)

53

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)

Method of Analysis

54

Future Business Simulation Work

Method of Analysis

3.2.1 Determine Value Hierarchy Weights• In conjunction with watermen and MDNR

4.3.3 Design Business Simulation4.3.4 Code Business Simulation4.3.5 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

55

Value Hierarchy

Method of Analysis

Aquaculture System Objective Function

Maximize Stakeholder Approval

Public Approval

Commercial Value

Maximize Sustainability

Return on Investment

Availability of Shell

Availability of Oyster from Hatchery

Maximize Water Quality

Decrease Sediment

Decrease Nutrients

Decrease Phosphoru

s

Decrease Nitrogen

0.33 0.30 0.37

0.40

0.60

0.20

0.30

0.50 0.50 0.50

0.25

0.25 Weights determined in conjunction with W/R Riverkeeper VIMS and SERC(Askvig et al, 2010)

56


57

Work Breakdown Structure (WBS)

Project Plan

WRR Aquaculture System

1.0 Management

1.1Work Breakdown Structure

1.1 Weekly Reports

1.2 Meeting Minutes

1.3 Budget

2.0 Research

2.1 Concept of Operations

2.2 Oyster

2.3 Legal

2.4 Environment

2.5 Business

2.6 Field Research

3.0 Design

3.1 Requirements

3.2 Value Hierarchy

4.0 Modeling

4.1 Oyster Growth Model

4.2 Business Model

4.3 VIMS Model

5.0 Analysis

5.1 Trade-off Analysis

5.2 Growth Model Analysis

5.3 Cost-Benefit Analysis

5.4 Long-Term Plan

6.0 Report

6.1 Papers

6.2 PowerPoint Presentations

6.3 Posters

58

Project Schedule

Project Plan

September October November December January February March April May

Management

Scope

Requirements

Design Alternatives

Model Research

Paper 1

Paper 2Final

Model Building

Competition Prep

Model V/V

Analysis

Utility Weights

Abstract

Poster

Paper

Final Proposal

59

Earned Value Management

Project Plan

0 5 10 15 20 25 30 35 400

10000

20000

30000

40000

50000

60000

70000

80000

90000

100000

Planned Value

Actual Cost

Earned Value

Week Number

Cost

Spe

nt ($

)

Planned Cost = $37,008Actual Cost = $25,050Earned Value = $39,720CPI = 1.48SPI = .93

60

Project Plan Risks and Mitigation

Project Plan

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

61

Questions?

62

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..

http://www.nytimes.com/2008/11/29/us/29poultry.html?partner=rss&emc=rss

http://www.dnr.state.md.us/dnrnews/infocus/oysters.asp

http://www.dnr.state.md.us/fisheries/oysters/industry/funding.asp

http://www.westrhoderiverkeeper.org/index.php/about-us/riverkeeper-program.html

http://www.dnr.state.md.us/fisheries/oysters/mtgs/111907/JudyOysHarvestsandRepletionProgram.pdf

http://www.hpl.umces.edu/hatchery/

http://ecsc.famu.edu/summaryiss.html

http://www.coastseafoods.com/triploid_oysters.html

http://www.terraqua.org/SI_oyster_biz_plan.pdf

http://www.cecilwhig.com/business/article_097d6b04-f803-11df-ac69-001cc4c002e0.html

63

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.

http://www.mainstreeteconomics.com/docs/MSERCfin.pdf

http://www.dnr.state.md.us/fisheries/news/story.asp?story_id=181

http://www.westrhoderiverkeeper.org/images/stories/PDF/West_River_Tech_Memo.pdf

http://www.dnr.state.md.us/irc/docs/00015769.pdf

http://www.oysterrecovery.org/Content/ContentDisplay.aspx?ContentID=118

http://www.mdsg.umd.edu/issues/chesapeake/oysters/garden/guide/seed/

64

Appendix I - Our Field Data

Station Depth (feet) Temp (C)Specific Conductance(uS) salinity (ppt)

Dissolved Oxygen % DO mg/L pH

w6 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

w20 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

AVG 23.23 5.86 3.17 89.57 7.48 8.21

Taken September 16, 2011

65

Appendix I - Our Field DataWest/Rhode River Sample 10/14/11

Station Depth (ft) Temp (°C) Salinity (ppt) DO (%) DO (mg/L) pH SC (μS)

W06 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

W20 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

CYC 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

66

Appendix II - Charts

October

1984

July 1987

April 1990

January

1993

October

1995

July 1998

March 2001

December

2003

Septem

ber 2006

June 2009

0

0.5

1

1.5

2

2.5

f(x) = − 3.54337518828152E-05 x + 2.09264983274883R² = 0.0803133399743463

Rhode River Secci Depth (1984 - 2011)

Secci Depth

Linear (Secci Depth)

Threshold

Date (month/year)

Secc

i Dep

th (m

)

67


2010 VIMS Model – Secchi Depth Improvement

68


Larvae

Seed

Spat-on-Shell

Cost

3 – 5 7 – 10

Ready to be placed in cages

Time (days)

69

Appendix III - DefinitionsTurbidity

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.

70

Appendix III - DefinitionsSalinity

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]

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Appendix III - Definitions

Shucked vs. Half Shell

Shucked

• Ability to reuse shell• Can be sold for canning• Multiple oyster larvae attach to one shell

Half Shell

• Can be sold to restaurants• Only one oyster per shell• Can typically be sold for

more• Shell is lost• Requires more marketing

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Appendix IV – Etc.Design Alternatives

Growth Method

Type of Cultch

Number of oysters on each shell

Final Product

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-on-Shell

N/A Full shell One Half shell, shucked

Hatchery to cages

Availability

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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 = (Th

2 + 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

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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

nsgd.gso.uri.edu/hawau/hawauw97002/hawauw97002_part6.pdf

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Example of Floating Cages

Context Analysis

(Webster, 2007)

west and rhode rivers aquaculture system

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