Eelgrass Mapping Review: Eelgrass Mapping Initiatives in Coastal British Columbia March 2003 For: Gretchen Harlow Canadian Wildlife Service 5421 Robertson Road Delta, B.C. V4K 3N2 By: Katherine Dunster, R.P.Bio. Dunster & Associates Environmental Consultants Ltd. P.O. Box 109 Bowen Island, B.C. V0N 1G0 25 March 2003 1 Table of Contents ACKNOWLEDGEMENT ............................................................................................................... 3 DEFINITIONS................................................................................................................................ 4 1.0 INTRODUCTION..................................................................................................................... 5 1.1 STUDY LIMITATIONS....................................................................................................... 5 1.2 METHODS........................................................................................................................... 6 1.3 RESULTS............................................................................................................................. 8 1.3.1 COARSE-SCALE MAPPING GAPS................................................................................ 8 1.3.2 FINE-SCALE MAPPING GAPS....................................................................................... 9 1.4 RECOMMENDATIONS.................................................................................................... 10 1.4.1 BUILDING THE WORKING GROUP NETWORK ...................................................... 10 1.4.2 LITERATURE SEARCH AND BIBLIOGRAPHY DEVELOPMENT ........................... 11 1.4.3 INFORMATION SHARING AND SECURING EXISTING INFORMATION .............. 11 1.4.4 FUNDING POSSIBILITIES AND PARTNERSHIPS..................................................... 12 1.5 SUMMARY........................................................................................................................ 12 2.0 PEOPLE CONTACTED..................................................................................................... 13 3.0 MAPPING INITIATIVES .................................................................................................. 17 3.1 COARSE-SCALE (REGIONAL) MAPPING PROJECTS................................................. 17 3.2 FINE-SCALE (LOCAL) M APPING PROJECTS .............................................................. 17 3.3 EELGRASS RESTORATION PROJECTS........................................................................ 17 3.4 HISTORICAL EELGRASS MAPPING PROJECTS......................................................... 18 3.5 EELGRASS RESEARCH PROJECTS/THESES ............................................................... 19 4.0 INVENTORY..................................................................................................................... 20 4.1 CONTINENTAL SLOPE........................................................................................................ 21 4.2 DIXON ENTRANCE .............................................................................................................. 23 4.3 HECATE STRAIT.................................................................................................................. 25 4.5 NORTH COAST FJORDS...................................................................................................... 29 4.6 QUEEN CHARLOTTE STRAIT............................................................................................ 37 4.7 JOHNSTONE STRAIT........................................................................................................... 41 4.8 STRAIT OF GEORGIA.......................................................................................................... 47 4.9 JUAN DE FUCA STRAIT....................................................................................................... 83 4.10 VANCOUVER ISLAND SHELF........................................................................................... 85 2 Table of Figures Figure 1. Marine Ecosections of British Columbia (source: LUCO)........................................ 7 Figure 2. Continental Slope Area. .......................................................................................... 21 Figure 3. Dixon Entrance Area. .............................................................................................. 23 Figure 4. Hecate Strait Area................................................................................................... 25 Figure 5. Queen Charlotte Sound Area. ................................................................................ 27 Figure 6. North Coast Fjords Area. ........................................................................................ 29 Figure 7. Queen Charlotte Strait Area. .................................................................................. 37 Figure 8. Johnstone Strait Area. ............................................................................................ 41 Figure 9. Strait of Georgia Area. ............................................................................................ 47 Figure 10. Juan de Fuca Strait Area. ....................................................................................... 83 Figure 11. Vancouver Island Shelf Area .................................................................................. 85 Acknowledgement Figures 2 through 11 are adapted from Canadian Hydrographic Chart L/C 3000, Juan de Fuca Strait to Dixon Entrance 1: 1 250 000, 1994. 3 ACRONYMS CMPB Coast and Marine Planning Branch, MSRM CWS Canadian Wildlife Service, Environment Canada DFO Department of Fisheries and Oceans Canada IOS Institute of Oceanographic Sciences LRMP Land Resource Management Plan LUCO Land Use Coordination Office, now in part Decision Support Services of the Resource Management Division, MSRM. LWBC Land and Water British Columbia MAFF B.C. Ministry of Agriculture, Fisheries and Food MSRM B.C. Ministry of Sustainable Resource Management NGO Non-governmental Organisation OCP Official Community Plan PBS Pacific Biological Station, Nanaimo (DFO) RLUP Regional Land Use Plan DEFINITIONS Eelgrass Eelgrass (Zostera marina and Zostera japonica ). Z. japonica is an introduced non- native species. Foreshore (intertidal) area The area between the mean high tide and low tide mark (i.e. below zero tide). Fine-scale Fine-scale maps (also known as large-scale maps) depict a small geographic area, with a large amount of detail. Intertidal The shore zone between the mean low water and the mean high water mark. The substrate is exposed and flooded by tides. Nearshore The subtidal area below low tide mark (i.e. below zero tide), generally extending to the 20 metre isobathymetric depth. Seagrass Eelgrass (Zostera marina and Zostera japonica ) and surfgrass (Phyllospadix scouleri and Phyllospadix torreyi). Coarse-scale Coarse-scale maps (also known as small-scale maps) depict a large geographic area, with a small amount of detail. 4 1.0 Introduction Since the turn of the millennium there has been an upsurge in grassroots interest in mapping and monitoring coastal eelgrass beds at the local level. Linked to that interest is the finite amount of funding, resources and support staff available to support grassroots initiatives. The overarching need for this review was to determine where there are geographical gaps in our knowledge of fine-scale eelgrass distribution throughout coastal B.C. In order to determine where new efforts should be focussed, it is important to know what work has already been initiated, and what areas are in most need of assistance due to resource management and other pressures. Three questions were asked: Where has eelgrass mapping been completed? And conversely, where has little or no eelgrass mapping been done? The answer to the first question forms Section 4.0 of this report, while the answer to the second question is summarized in Section 1.3 (Results) and Section 1.4 (Recommendations) below. Once the gaps were determined, the third question attempted to ask what areas most urgently needed mapping assistance or help organizing a mapping initiative, and what areas were under the most pressure (for example, finfish or shellfish aquaculture expansion, harbour development)? During the course of this project it became apparent that in addition to finding answers to the two mapping questions, it would also be worthwhile documenting eelgrass restoration and eelgrass research projects in each marine ecoregion. Eelgrass restoration projects date back to around 1990, and there are several reasons for keeping track of where they have been done: 1) to ensure that contemporary mapping, monitoring and restoration projects are cognizant of the locations of previous restoration efforts; 2) to allow grassroots groups and others to continue monitoring restoration projects in their areas long after “official” or statutory monitoring has ended; and 3) to provide contemporary restoration projects with a local benchmark for comparative purposes. The eelgrass research category is a start at documenting the research efforts of universities, government agencies and industry. The projects in the 1980’s and 1990’s have for the most part provided insight into marine vegetation inventory, mapping and classification techniques. The results are often useful to contemporary eelgrass mappers because the plot data from research sites provide both historical context and valuable information about