An Assessment of Potential Water Column Impacts of Mussel Raft Culture in Totten Inlet
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An Assessment of Potential Water Column Impacts Of Mussel Raft Culture in Totten Inlet November 2009 Prepared for: Taylor Resources, Inc. 130 Southeast Lynch Road Shelton, Washington 98584 Prepared by: PO Box 216 4729 NE View Drive Port Gamble, Washington 98364 An Assessment of Potential Water Column Impacts of Mussel Raft Culture in Totten Inlet November 2009 Prepared for: TAYLOR RESOURCES, INC. 130 SOUTHEAST LYNCH ROAD SHELTON, WASHINGTON 98584 Prepared by: NEWFIELDS LLC P.O. BOX 216 4729 NE VIEW DRIVE PORT GAMBLE, WASHINGTON 98364 November 2009 Table of Contents 1. Introduction..................................................................................................................................1 1.1. Totten Inlet........................................................................................................................1 1.2. Mussel Rafts Proposed For NTI Site................................................................................2 1.3. Objectives.........................................................................................................................3 1.4. Data Sources....................................................................................................................4 2. Effects of Mussel Rafts on Water Flow .......................................................................................5 2.1. Physical Attributes of Totten Inlet.....................................................................................5 2.1.1. Currents in North Totten Inlet ..................................................................................6 2.1.2. Residence Time and Flushing Rates.......................................................................8 2.1.3. Effects of Mussel Rafts on Water Flow..................................................................10 2.1.4. Flow in the Immediate Vicinity of the Rafts............................................................11 2.1.5. Flow Downstream of the Rafts...............................................................................15 2.1.6. Summary................................................................................................................17 3. Dissolved Oxygen .....................................................................................................................18 3.1. Effects of Mussel Rafts on Dissolved Oxygen................................................................21 3.2. Summary ........................................................................................................................24 4. Effects of Mussel Rafts on Nutrients .........................................................................................25 4.1. Mussel Biology ...............................................................................................................25 4.2. Nutrient Sensitivity..........................................................................................................26 4.3. Nutrients in Totten Inlet ..................................................................................................28 4.3.1. Silicate ...................................................................................................................29 4.3.2. Phosphorous..........................................................................................................32 4.3.3. Nitrogen .................................................................................................................34 4.4. Summary ........................................................................................................................48 5. Effects of Mussel Rafts on Phytoplankton.................................................................................50 5.1. Phytoplankton in Totten Inlet..........................................................................................50 5.1.1. Species Composition and Abundance...................................................................50 5.1.2. Plankton Biomass and Chl a..................................................................................52 5.2. Mussel Raft Effects on Phytoplankton............................................................................56 5.2.1. Effects on Phytoplankton Abundance....................................................................57 5.2.2. Effects on Chlorophyll and Biomass......................................................................59 5.2.3. Effects of Turbulent Mixing ....................................................................................62 5.2.4. Mixing Model, Recovery Rates, and Primary Production ......................................66 5.2.5. Summary................................................................................................................67 6. Mussel Raft Effects on Food Web.............................................................................................69 6.1. Habitat in Totten Inlet .....................................................................................................69 6.2. The Food Web in Totten Inlet.........................................................................................69 6.2.1. Phytoplankton ........................................................................................................70 6.2.2. Microzooplankton...................................................................................................70 6.2.3. Zooplankton ...........................................................................................................71 6.2.4. Gelatinous Zooplankton.........................................................................................71 6.2.5. Bivalve Mollusk Shellfish .......................................................................................72 6.2.6. Adult Herring..........................................................................................................72 6.2.7. Forage Fish and Salmonids...................................................................................73 6.2.8. Other Food Web Links...........................................................................................74 6.3. Carbon Flow Model for Cultivated Mussels and Mussel Production..............................76 6.3.1. Role of Pseudofeces in Carbon Flow Model .........................................................77 6.3.2. Role of Diet Composition in Carbon Flow Model...................................................78 6.3.3. The Role of Fouling Organisms in Mussel Raft Consumption Estimates..............79 6.3.4. Estimating Carbon Sequestration using Seasonal Production of Cultivated Mussels..................................................................................................................80 NewFields LLC i November 2009 6.3.5. Mussel Rafts Effects on Water-Column Food Web in Totten Inlet ........................82 6.4. Summary ........................................................................................................................87 7. Conclusions...............................................................................................................................89 8. References ................................................................................................................................93 List of Tables Table 1. Summary of Projected Harvest from the Proposed North Totten Inlet Rafts ......................4 Table 2. Dissolved Oxygen Concentrations at the Deepwater Point Raft Array. ............................22 Table 3. Predicted Concentration of Ammonium within the Raft at a Current Speed of 10 cm/s and 25 cm/s...............................................................................................................................40 Table 4. Data Supporting Nitrogen Flow Model for Totten Inlet. .....................................................42 Table 5. Individual Growth Rates and Production for Deepwater Point Mussel Rafts. ...................44 Table 6. Average Monthly Chlorophyll a, Standing Stock, and Biomass for Totten Inlet. ...............55 Table 7. Predicted Changes in Phytoplankton Biomass Based on Deepwater Point Raft Surveys.60 Table 8. Model Parameters and Output for the Time to Reach Ambient Conditions following the NTI Rafts and Turbulent Mixing Zone...............................................................................67 Table 9. Individual Growth Rates and Production for Deepwater Point Mussel Rafts. ...................81 Table 10. Spring/Summer Carbon Flow and Consumption Estimates ............................................83 Table 11. Fall/Winter Production and Consumption Estimates .......................................................83 Table 12. Monthly Spring/Summer Estimates for NTI Mussel Raft Production and Phytoplankton Consumption and Relative Importance in Totten Inlet. ....................................................85 Table 13. Monthly Estimates during Fall/Winter for NTI Mussel Raft Production and Phytoplankton Consumption and Relative Importance in Totten Inlet....................................................86 List of Figures Figure 1. Location of Proposed Mussel Raft Facility in Totten Inlet, Washington. .............................2 Figure 2. Approximate Location of Proposed Mussel Rafts at the North Totten Inlet Site. ................3 Figure 3. Hydraulic Linkages between Totten Inlet, WA and Surrounding Water Bodies in South Puget Sound, WA....................................................................................................5