88073746 OCEANIC ENGINEERING Volume II SYNTHESIS OF FINDINGS I «=v. ?: BIOLOGICAL AND GEOLOGICAL RECONNAISSANCE AND CHARACTERIZATION SURVEY OF THE TANNER AND CORTES BANKS Prepared for UNITED STATES DEPARTMENT OF INTERIOR BUREAU OF LAND MANAGEMENT under contract AA551-CT8-43 TD 195 . P4 T36 1979 v. 2 j * ezbtfyi:* INTERSTATE 1001 East Ball Road ELECTRONICS Post Office Box 3117 CORPORATION Anaheim, California 92803 SUBSIDIARY OF Telephone (714) 635-7210 or (714) 772-2811 TWX U.S.A. 910-591-1197 TELEX 655443 i<m A%IO Volume II v. 2. Oceanic SYNTHESIS OF FINDINGS Engineering / BIOLOGICAL AND GEOLOGICAL RECONNAISSANCE AND CHARACTERIZATION SURVEY OF THE TANNER AND CORTES BANKS This study was supported by the Bureau of Land Management, Department of the Interior under contract AA551-CT8-43 SEPTEMBER 1979 This report has been reviewed by the Bureau of Land Man¬ agement and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the Bureau, nor does mention of trade names or commercial products constitute endorsement nr ro^nmmon. dations for use. Prepared by - OCEANIC ENGINEERING OPERATIONS INTERSTATE ELECTRONICS CORPORATION VOLUME II PROGRAM PARTICIPANTS The following personnel participated in the conduct of the survey work and the writing and preparation of the final report and other deliverables under this contract to the Bureau of Land Management. Name Responsibility Discipline G.L. Bane General Manager M.S. Mechanical Eng W.B. Merselis Program Manager, Phase II M.S. Geology Party Chief, Principal Author N.B. Plutchak Chief Scientist, Data M.S. Oceanography Analysis, Author P.C. Day Marine Geologist, Phase I M.S. Geology Party Chief, Author A.L. Lissner Marine Biologist (ecology), Ph.D. Biology Phase II Party Chief, Observer, Author D.G. Harden Marine Biologist (coral), Ph.D. Biology Observer, Author K.M. Stoddard Marine Biologist (fish), B.A. Biology Observer, Author T.R. Kendall Photographer (Movies) Ph.D. Oceanography M.F. Valenti Technical Editor, B.A. English J.F. Wellman Graphics Specialist, A.A. Oceanographic Cartography Technology Field Data Collection: Data Analysis and Interpretation: J. Ambrosius, B.S. Biology J. Ambrosius, B.S. Biology D. Johnson, B.A. Geology H. Avera, B.S. Biology and Chemistry E. Lawrence, B.S. Geology L. Doull, B.A. Geology J. Lettow, A.A. Ocean Technology R. Wright, M.S. Biology C. McFarlane, Studies in Oceanography Report Preparation: K. Buckles M. Kittridge S. Heckelman J. Villa Consultant Organization/Contribution Dr. J. Engle, Catalina Marine Science Center, Scientific Observer, Community Review and Comparison C. Finkelstein, Sidescan Consultant Dr. R. Given, Catalina Marine Science Center, Community Review and Comparison Dr. R. Grigg, University of Hawaii, Scientific Observer, Review of unique features and Coral Harvesting potential. Dr. W. Newman, Scripps Institution of Oceanography, Community Review and Comparison Dr. R. Rosenblatt, Scripps Institution of Oceanography, Community Review and Comparison J. Word, Southern California Coastal Water, Research Project, Scientific Observer, Community Review and Comparison II ii CONTENTS Section Title Page 1 INTRODUCTION . 1-1 1.1 BACKGROUND.1-1 1.2 STUDY OBJECTIVES . 1-3 1.3 NOTABLE FINDINGS OF THIS STUDY.1-4 1.4 POTENTIAL IMPACTS . 1-5 1.5 ACKNOWLEDGMENTS.1-7 2 FIELD AND DATA ANALYSIS METHODS . 2-1 2.1 GEOLOGY.2-1 2.1.1 Research Vessel R/V VELERO IV.2-1 2.1.2 Navigation.2-1 2.1.3 Bathymetry.2-2 2.1.4 Side Scan Sonar.2-2 2.2 BIOLOGY.2-2 2.2.1 Cruise Plan Preparation.. 2-2 2.2.2 Equipment Preparation . 2-2 2.2.3 Submersible Operations . 2-3 2.2.4 Transect Activities . 2-3 2.2.5 Movie Production . 2-5 2.3 ANALYSIS.2-5 2.3.1 Geology.2-5 2.3.2 Biology.2-6 3 GEOLOGY AND OCEANOGRAPHY DISCUSSION . 3-1 3.1 GEOLOGY.3-1 3.1.1 Geologic Setting . 3-1 3.1.2 Pertinent Previous Studies . 3-2 3.1.3 Applicability of Previous Studies . 3-2 3.1.4 Interpretations.3-3 3.1.5 Bathymetric and Geomorphic Analysis of Study Areas .3-5 3.1.6 Regional Findings . 3-16 3.2 OCEANOGRAPHY.3-17 4 BIOLOGICAL OBSERVATIONS . 4-1 4.1 COMMUNITIES.4-1 4.1.1 Eisenia/Calliarthron Community . 4-3 4.1.2 Agarum/Laminaria Community . 4-6 4.1.3 Encrusting Coralline Community . 4-6 4.1.4 Florometra/ophiuroid Community . 4-7 4.1.5 Sand Community.4-3 ;i iii CONTENTS (continued) Section Title Page 4.2 AREA DESCRIPTIONS.4-9 4.2.1 Bishop Rock Communities (Area A Plate 5 Map 1).4-9 4.2.2 Nine-Fathom Reef Communities (Area B, Plate 5 Map 2) . 4-9 4.2.3 Northwest Cortes Bank Communities (Area C, Plate 5 Map 3).4-12 4.2.4 Central Tanner Bank Communities (Area E, Plate 5 Map 5).4-14 4.2.5 Northwest Tanner Bank Communities (Area F, Plate 5 Map 6).4-14 4.2.6 Santa Rosa Ridge Communities (Area G). 4-17 4.3 CORAL DISTRIBUTION AND DENSITY . 4-17 4.3.1 Hydrocoral.4-17 4.3.2 Stony Coral.4-32 4.3.3 Fan Corals.4-33 4.4 FISH.4-36 4.5 FISH DISTRIBUTION.4-39 4.6 MACROALGAE.4-45 4.7 OTHER SELECTED SPECIES . 4-48 4.7.1 Annelida._.4-48 4.7.2 Brachiopoda.4-48 4.7.3 Bryozoa (Ectoprocta) . 4-48 4.7.4 Coelenterata.4-48 4.7.5 Crustacea.4-50 4.7.6 Echinodermata (Sea Urchins, Sea Cucumbers, Sea Lilies, Sea Stars and Brittle Stars) . 4-50 4.7.7 Mollusca.4-51 4.7.8 Porifera (Sponges) . 4-52 4.7.9 Urochordata (Tunicates) . 4-53 4.7.10 Comparison with Historical Data.4-53 4.8 PREVIOUS STUDIES . 4-53 4.8.1 Shallow Water Communities . 4-57 4.8.2 Mid-Depth Communities . 4-60 4.8.3 Deep-Water Communities . 4-64 4.8.4 Allopora.4-65 4.8.5 Marine Mammals.4-66 4.8.6 Site-Specific Comparisons . 4-66 4.9 UNIQUENESS.4-69 5 SUMMARY AND CONCLUSIONS . .5-1 5.1 GEOLOGY.5-1 5.2 OCEANOGRAPHY.5-3 5.3 BIOLOGY.5-3 5.3.1 Community Structure and Macroalgae Distribution .... 5-3 5.3.2 Community Comparisons and Species Distributions Between Areas . 5-4 5.3.3 Fish Distribution and Density.5-6 5.3.4 Comparisons.5-7 II iv CONTENTS (continued) Section Title Page 6 RECOMMENDATIONS . 6-1 6.1 GEOLOGY.6-1 6.2 BIOLOGY.6-1 6.2.1 Submersible Techniques . 6-1 6.2.2 Data Collection.6-2 6.2.3 Data Analysis.6-4 6.2.4 Adequacy of Existing Data.6-4 6.2.5 Recommendations for Additional Data.6-4 7 REQUIRED MAPS AND OVERLAYS.7-1 7.1 MAPS AND OVERLAYS.7-1 7.2 MICROFILM AND MICROFICHED DATA.7-1 8 REFERENCES.8-1 8.1 GEOLOGY.8-1 8.2 OCEANOGRAPHY.8-2 8.3 BIOLOGY.8-2 APPENDICES A BATHYMETRIC CRUISE REPORT . A-l B REPORT OF BATHYMETRIC CHARTING . B-l C REPORT OF SIDESCAN SONAR CHARTING . C-l D FIELD METHODS AND ANALYSIS . D-l E TRANSCRIBED OBSERVER, VIDEO, AND BENTHOS DIVE LOGS . E-l F DENSITY - DEPTH PLOTS . F-l G CRUISE REPORT SUBMERSIBLE OPERATIONS #1 AND #2 G-l H SPECIES OCCURRENCES AT TANNER AND CORTES BANK AND SANTA ROSA RIDGE AS RECORDED- BY SUBMERSIBLE OBSERVERS, VIDEO CAMERA, AND BENTHOS CAMERA . H-l > II v CONTENTS (continued) Section Title Page ILLUSTRATIONS Number Title Page II-l Location Map of Tanner and Cortes Banks and the Seven Study Areas (A-G).1-2 II-2 Two-Man Submersible, NEKTON GAMMA, with Camera Mounted on Bow . 2-4 II-3 Species Card.2-7 II-4 Bathymetric and Side Scan Sonar Survey Areas.3-4 II-5 Bathymetry and Cross-Section—Tanner Bank (Area E).3-6 II-6 Reconnaissance Geology and Geomorphology of Tanner Bank (Area E).3-7 II-7 Surface Circulation to 100-meter Depth in Southern California Bight.3-13 II-8 Submersible Survey Transect Coverage . 4-2 II-9 Relative Abundances by Depth of Common Organisms . 4-5 11-10 Benthic Communities Observed in Area A.4-10 11-11 Benthic Communities Observed in Area B.4-11 11-12 Benthic Communities Observed in Area C.4-13 11-13 Benthic Communities Observed in Area E.4-15 11-14 Benthic Communities Observed in Area F.4-16 11-15 Depth Distribution of Allopora californica for Colonies of all Sizes, Colonies Taller than 7 cm and Purple Colonies (Other Colonies are Probably Pink in Color) . 4-20 11-16 Distribution of Allopora californica Area A . 4-22 11-17 Distribution of Allopora californica Area B . 4-23 11-18 Distribution of Allopora californica Area E . 4-25 11-19 Distribution of Allopora californica Area F . 4-26 11-20 Allopora Height/Weight Curve Showing Mean (o) Values (3) for Height Intervals for 245 Colonies Harvested from Bishop Rock.4-31 11-21 Fish Distribution Tanner Bank Area E.4-40 TABLES II-l Scales of Pertinent Data.3-3 II-2 Communities Observed at Tanner and Cortes Banks . 4-3 II-3 Depth Distributions (Meters) of Allopora in Study Areas with Maximum Height, Widty, Coverage and Density Estimates for Each Community.4-21 II-4 The Estimated Extent of Rocky Habitat and Frequency of Observation of Allopora Colonies in Each Area.4-27 II-5 Estimated Suitable Habitat (Square Km) Available to Allopora on Tanner and Cortes Banks .