Lucy Islands Eelgrass Study June 2011 Research carried out by Ocean Ecology 1662 Parmenter Ave. Prince Rupert, BC V8J 4R3 Telephone: (250) 622-2501 Email: [email protected] In partnership with WWF Funding provided by MEC Lucy Islands Eelgrass Study Lucy Islands Eelgrass Study Prepared for: Mike Ambach Program Manager World Wildlife Fund - Prince Rupert #3-437 3rd Ave. West Prince Rupert BC V8J 1L6 Prepared by: Ocean Ecology © 1986 Panda symbol WWF-World Wide Fund For Nature (also known as World Wildlife Fund). ® “WWF” is a WWF Registered Trademark. ® Mountain Equipment Co-op logo is a trade-mark of Mountain Equipment Co-operative, © 2011, Mountain Equipment Co-operative. Ocean Ecology Lucy Islands Eelgrass Study Table of Contents Table of Contents ............................................................................................................................. ii List of Figures .................................................................................................................................. iv List of Tables .................................................................................................................................. vii Executive Summary ....................................................................................................................... viii 1 Introduction ............................................................................................................................... 1 2 Lucy Islands Eelgrass Survey Methodology ............................................................................ 8 2.1 Overall Project Design ...................................................................................................... 8 2.2 Single-Beam Sounder Bathymetric Survey ....................................................................... 9 2.2.1 Single-Beam Sounder System ................................................................................... 9 2.2.2 Survey Design ............................................................................................................ 9 2.2.3 Depth Grids and Contour Plots ................................................................................ 11 2.3 Towed Benthic Video Survey .......................................................................................... 11 2.3.1 Towed Video System ............................................................................................... 11 2.3.2 Video Recording System ......................................................................................... 12 2.3.3 Survey Design .......................................................................................................... 12 2.4 Classification and Mapping ............................................................................................. 16 2.4.1 Database of Species and Substrate Classifications ................................................ 16 2.4.2 ArcGIS Mapping ....................................................................................................... 16 2.4.3 Substrate Maps ........................................................................................................ 17 2.4.4 Range Maps ............................................................................................................. 17 2.4.5 Eelgrass Maps ......................................................................................................... 17 2.4.6 Diversity Analysis Using Range Maps ..................................................................... 18 2.4.7 Species Richness Maps........................................................................................... 18 2.5 High Definition Drop Camera Survey .............................................................................. 19 2.5.1 Drop Camera System .............................................................................................. 19 2.5.2 Survey Design .......................................................................................................... 20 2.5.3 Photograph Analysis ................................................................................................ 20 2.6 Side Scan Sonar Survey ................................................................................................. 22 2.6.1 Side Scan Sonar System ......................................................................................... 22 2.6.2 Survey Design .......................................................................................................... 23 2.6.3 Viewing of Raw Side Scan Sonar Data ................................................................... 23 2.6.4 Simple Georeferencing and Mosaicing of the Side Scan Sonar Data ..................... 23 2.6.5 Calculation of Eelgrass Cover Using Grey Level Co-occurrence Matrices (GLCM) 24 2.6.6 Processing of Side Scan Sonar Data ...................................................................... 25 2.6.7 Bottom Hardness ..................................................................................................... 25 2.6.8 Calculation of Eelgrass Height ................................................................................. 25 2.6.9 Macrophyte Height Profiles ...................................................................................... 26 2.6.10 Observations of Anthropogenic Disturbances in the Eelgrass Bed ......................... 26 2.7 Multibeam Sonar Survey ................................................................................................. 28 2.7.1 Multibeam Sonar System ......................................................................................... 28 2.7.2 Survey Design .......................................................................................................... 28 2.7.3 Processing of Multibeam Sonar Data ...................................................................... 28 2.8 Beach Seining ................................................................................................................. 30 2.8.1 Survey Design .......................................................................................................... 30 2.8.2 Organism Identification ............................................................................................ 30 2.9 Bird Observations ............................................................................................................ 31 2.10 Observations of Human Activities ............................................................................... 31 3 Lucy Islands Eelgrass Study Results and Discussion ........................................................... 32 3.1 Eelgrass Observations in the Upper Intertidal Zone ....................................................... 32 3.2 Single-beam Sonar Bathymetric Survey ......................................................................... 35 3.2.1 Bathymetry ............................................................................................................... 35 3.3 Benthic Video Survey ...................................................................................................... 37 3.3.1 Substrate .................................................................................................................. 37 ii Ocean Ecology Lucy Islands Eelgrass Study 3.3.2 Flora ......................................................................................................................... 42 3.3.3 Fauna ....................................................................................................................... 54 3.3.4 Diversity ................................................................................................................... 59 3.4 High Definition Drop Camera Survey .............................................................................. 64 3.5 Side Scan Sonar Survey ................................................................................................. 68 3.5.1 Raw Side Scan Sonar Data ..................................................................................... 68 3.5.2 Simple Georeferencing and Mosaicing of the Side Scan Sonar Data ..................... 70 3.5.3 Calculation of Eelgrass Cover Using Grey Level Co-occurrence Matrices (GLCM) 76 3.5.4 Processing of Side Scan Sonar Data ...................................................................... 81 3.5.5 Bottom Hardness ..................................................................................................... 91 3.5.6 Calculation of Eelgrass Height ................................................................................. 96 3.5.7 Macrophyte Height Profiles .................................................................................... 101 3.5.8 Observations of Anthropogenic Disturbances in the Eelgrass Bed ....................... 104 3.6 Multibeam Sonar Survey ............................................................................................... 108 3.7 Beach Seining ............................................................................................................... 110 3.8 Bird Observations .......................................................................................................... 112 3.9 Observations of Human Activities ................................................................................. 114 3.10 Feasibility Study for Placement of Fixed Anchors ..................................................... 114 4 Project Outcomes as Related