Mussel growth and food utilization in relation to water column conditions on raft systems in Puget Sound, Washington Dan Cheney, Andrew Suhrbier, Aimee Christy, Hector Beltran, Joth Davis, Kenn Brooks and Frank Smith Sea Grant National Marine Aquaculture Initiative Pacific Shellfish Institute, Taylor Shellfish Farms, Penn Cove Shellfish, Aquatic Environmental Science Lab and NorthWest Research Associates PSI/Taylor Shellfish - 1
Project Objectives Growth and yield against measured water column parameters Concurrent measurements of feeding and biodeposit production Comparative experiments at differing growout locations Modeling farm scale carrying capacity PSI/Taylor Shellfish - 2
Key Environmental Issues Effects of suspended shellfish culture in PS on: Physical and chemical characteristics of the water column Phytoplankton and zooplankton The benthos Native species of mussels and other shellfish Fishery resources, especially ESA listed PSI/Taylor Shellfish - 3
Kenai Peninsula Seward Kachemak Bay Strait of Juan de Fuca Olympic Peninsula Puget Sound Seattle PSI/Taylor Shellfish - 4
PSI/Taylor Shellfish - 5 Totten Inlet
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315 7.5 5 45 2.5 27 9 2.5 5 7.5 225 135 18 315 7.5 45 5 2.5 27 9 2.5 5 7.5 225 135 18 1 12.5 315 7.5 45 315 5 45 315 1 45 315 7.5 45 27 9 27 2.5 2.5 5 9 7.5 5 27 5 2.5 9 5 2.5 2.5 2.5 5 7.5 1 2.5 5 27 7.5 1 12.5 2.5 5 7.5 9 225 135 225 135 225 135 225 135 18 27 18 27 315 225 315 225 7.5 5 2.5 18 12.5 1 7.5 5 2.5 18 18 9 2.5 5 7.5 1 12.5 45 2.5 5 7.5 135 45 135 9 18 N Water Flow LEGEND 2 315 15 45 1 27 to 1 cm/sec 11 to 2 cm/sec 21 to 3 cm/sec 31 to 4 cm/sec 41 to 5 cm/sec 5 5 1 15 2 225 135 18 PSI/Taylor Shellfish - 9 9
Outside Inside Location Authors 7.6 1.11 Saldanha Bay, S. Africa Boyd & Heasman, 1998 5.2 Loch Etive & Kishorn, Scotland Karayuecel & Karayuecel, 1998 14.2-16.5 2.9-3.4 Totten Inlet, Puget Sound Present study net 1.78 same (1 day only) Present study wo net 1.81 same (1 day only) Present study 18.7 Totten Inlet, outer Brooks, 2 PSI/Taylor Shellfish - 1
Growth Size, all Raft Units Histogram of Length 8. 9 6. Count 4. Length (mm) 68 46 24 2.. 15 3 45 6 35. Length Histogram of Length 2 262.5 2 3 4 5 6 7 8 9 1 Count 175. Month 87.5. 2 4 6 8 1 PSI/Taylor Shellfish - 11 Length
Growth Size vs Location Position on a Unit Outside and Center Position on all Units North to South PSI/Taylor Shellfish - 12
Growth Size vs Location / Size vs Depth Analysis of Variance Table Source Prob Term DF F-Ratio Level A: Date 6 5641.9.* B: Unit 5 653.7.* AB 3 3..* C: Location 8 24..* AC 48 5..* BC 4 35.3.* ABC 24 5.7.* * Term significant at alpha =.5 Length (mm) 45 34 24 13 2 1 m 3 m 5 m Water Depth PSI/Taylor Shellfish - 13
Growth Wet and Dry Weights for all Units R-Squared.854 PSI/Taylor Shellfish - 14
Chlorophyll vs Phytoplankton 3 25 2 ug/l 15 1 5 15-Apr 2-Apr 25-Apr 3-Apr 5-May PSI/Taylor Shellfish - 15
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Phytoplankton sampling PSI/Taylor Shellfish - 17
Phytoplankton observations 3,5, 3,, 2,5, Diatoms Dinoflagellates 2,, 1,5, 1,, 5, M-2 A-2 M-2 J-2 J-2 A-2 S-2 Cells/L PSI/Taylor Shellfish - 18
Table 1. Species Inventory* Centric Diatoms Pennate Diatoms Dinoflagellates Flagellates Actinoptychus senarius Achnanthes sp. Akashiwo sanguinea Meringosphaera sp. Asteromphalus sp. Cylindrotheca closterium Alexandrium spp. Cryptomonads Cerataulina pelagica Fragilaria spp. Amylax triacantha Dictyocha spp. Chaetoceros spp. Fragilariopsis spp. Ceratium spp. Euglenophyceae Corethron hystrix Licmophora spp. Dinophysis spp. Ebria tripartita Coscinodiscus spp. Navicula spp. Gonyaulax spp. Dactyliosolen spp. Nitzschia ascicularis Gyrodinium spp. Detonula pumila Pseudo-nitzschia spp. Heterocapsa triquetra Ditylum brightwellii Striatella unipunctata Kofoidinium velleloides Eucampia zodiacus Thalassionema nitzschioides Noctiluca scintillans Grammatophora sp. Tropidoneis antarctica Oxyphysis oxytoxoides Guinardia delicatula Unidentified pennate Prorocentrum spp. Hemiaulus sp. Protoperidinium spp. Lauderia annulata Scrippsiella trochoidea Leptocylindrus spp. Unidentified Dinos Melosira moniliformis Odontella spp. Plagiogrammopsis vanheurckii Proboscia alata Rhizosolenia spp. Skeletonema costatum Stephanopyxis spp. Thalassiosira spp. Unidentified centric PSI/Taylor Shellfish - 19
Phytoplankton clearance Location/Tide Ave Cells/L St dev % Decrease from N. Boom P Value North Boom/Incoming 929,654 86,646 Center/Incoming 176,52 161,643 7.6.6 South Boom Incoming 816,457 843,968 24.7.615 South Buoy Incoming 963,333 537,751 4.2.4796 PSI/Taylor Shellfish - 2
Cells/L/1 2 18 16 14 12 1 8 6 4 2 8/5/22 8/3/22 9/16/22 1/18/22 Control N. Buoy N. Boom Center S. Boom S. Buoy PSI/Taylor Shellfish - 21
Mussel feeding efficiency/selectivity? 6, 5, 4, R 2 =.2571 3, 2, Center Cells/L 1, 1,8, 2, 4, 6, 8, 1,, 1,2, 1,4, 1,6, N. Boom Cells/L PSI/Taylor Shellfish - 22
Species Ave N. Boom Ave Center % Decrease St dev Centric Diatoms Chaetoceros spp. 285,216 68,552 68.4 39.9 Eucampia zodiacus 83,826 5,57 6.9 46.1 Thalassiosira spp. 35,25 2,832 55.6 28.5 Pennate Diatoms Thalassionema nitzschioides 13,338 2,325 77.9 44.5 Pseudo-nitzschia sp. 29,474 4,429 76 48. Dinoflagellates Ceratium fusus 3,82 6,248 79.4 7.9 Akashiwo sanguinea 85,79 58,79 26 2.6 Protoperidinium spp. 2,67 1,66 42.9 44.4 PSI/Taylor Shellfish - 23
The Mussel Farm Ecosystem 4 mo 9 mo 11 mo 15 mo PSI/Taylor Shellfish - 24
Summary Water currents lower in mussel culture system than at control stations Mussel growth in PS similar to other productive waters and mirrors trends in phytoplankton densities Mussel lengths and weights are uniform within the raft Phytoplankton densities decrease in culture system but recover within a few meters downstream Phytoplankton feeding appeared to be selective Sediment deposition largely limited to the footprint of the raft units (companion study) Ecology within system during culture cycle is complex and not well described for PS PSI/Taylor Shellfish - 25