Great Barrier Reef Water Quality Protection Plan Marine Monitoring Program Intertidal Seagrass FINAL REPORT For the Sampling Period 1st September 2007 – 31st May 2008 Len McKenzie1 Jane Mellors2 and Michelle Waycott3, 1Northern Fisheries Centre, Queensland Department of Primary Industries & Fisheries, PO Box 5396, Cairns, Qld, 4870, Australia. 2 Northern Office Townsville, Queensland Department of Primary Industries & Fisheries, PO Box 1085, Townsville, Qld, 4810, Australia. 3 School of Marine and Tropical Biology, James Cook University Townsville Marine and Tropical Sciences Research Facility Project 1.1.3 Condition trend and risk in coastal habitats: Seagrass Indicators, distribution and thresholds of potential concern. Acknowledgements We thank our technical staff and consultants for their assistance with field collections, laboratory processing and data management: Naomi Smith, Rudi Yoshida, Rebecca Bowie, Trischelle Lowry, Matt Lowry, Christina Howley and Kelly Jacobs. We also thank the following Seagrass-Watch volunteers (just to name a few) who gave up their weekends and free-time to assist with the field monitoring: Posa Skelton, Margaret Parr, Tom Collis, Lux Foot, Don Kinsey, Barbara Kinsey, Jason Vains, Michelle Jones, Matt Bloor, Noel Kane, John Ryder, Alice Kay, Helen Debnam, Sunnee Goudy, Sandra Hardy, Dell Williams, John Williams, Betty Wilson, Robina Mealey, Sally Cowan, Jamie Havighurst, Dick Wickenden, Steve McGuire, Rose, Jean Hughes, Alisha Stewart, Jenny Tenney, David Reid, Linda Davis, Greg Lynch, Sharon Taylor, Susan Crocetti, Kellie Lobb, Hugh Kirkman, Blair Wilson, Carla Wegscheidl, Kinam Salee, Kristie McNamara, Masau (Yogi) Yoshida, Nicky Yoshida and Kim Hodgson. We also thank Rob Coles, Catherine Collier, Joelle Prange and David Haynes for their guidance and scientific discussions regarding the program. TABLE OF CONTENTS Acknowledgements................................................................................................................... 3 Executive summary................................................................................................................... i 1. Introduction .......................................................................................................................... 1 Background ........................................................................................................................... 1 Methodolgy ............................................................................................................................ 3 Inter-tidal seagrass monitoring............................................................................................. 3 Edge mapping........................................................................................................................ 3 Seagrass reproductive health (status)................................................................................... 1 Seagrass tissue nutrient......................................................................................................... 2 Sediment nutrient .................................................................................................................. 2 QA/QC procedures ................................................................................................................3 Reporting Approach ..............................................................................................................7 2. Results ................................................................................................................................. 10 Cape York NRM .................................................................................................................. 10 Background......................................................................................................................... 10 Seagrass cover and composition......................................................................................... 11 Seagrass reproductive health .............................................................................................. 13 Tissue nutrients................................................................................................................... 13 Seagrass Tissue Nutrients Ratios........................................................................................ 15 Seagrass meadow edge mapping ........................................................................................ 17 Epiphytes and macro-algae................................................................................................. 18 Sediment nutrients .............................................................................................................. 19 Sediment herbicides............................................................................................................ 20 Within meadow canopy temperature.................................................................................. 20 Wet Tropics NRM................................................................................................................ 22 Seagrass cover and composition......................................................................................... 23 Seagrass reproductive health .............................................................................................. 27 Tissue nutrients................................................................................................................... 28 Seagrass Tissue Nutrient Ratios ......................................................................................... 31 Discussion seagrass tissue nutrients and nutrient ratios ..................................................... 34 Seagrass meadow edge mapping ........................................................................................ 35 Epiphytes and macro-algae................................................................................................. 36 Sediment nutrients .............................................................................................................. 38 Sediment herbicides............................................................................................................ 40 Within meadow canopy temperature.................................................................................. 40 Burdekin Dry Tropics.......................................................................................................... 44 Background......................................................................................................................... 44 Seagrass cover and composition......................................................................................... 46 Seagrass reproductive health .............................................................................................. 49 Tissue nutrients................................................................................................................... 49 Tissue nutrient ratios .......................................................................................................... 52 Epiphytes and Macro-algae ................................................................................................ 55 Seagrass meadow edge mapping ........................................................................................ 56 Sediment nutrients .............................................................................................................. 57 Sediment herbicides............................................................................................................ 58 Within meadow canopy temperature.................................................................................. 59 Mackay – Whitsunday......................................................................................................... 62 Seagrass cover and composition......................................................................................... 63 Seagrass reproductive health .............................................................................................. 67 Tissue Nutrients.................................................................................................................. 67 Tissue nutrient ratios .......................................................................................................... 71 Epiphytes and Macro-algae ................................................................................................ 74 Seagrass meadow edge mapping ........................................................................................ 75 Sediment nutrients .............................................................................................................. 77 Sediment herbicides............................................................................................................ 78 Within meadow canopy temperature.................................................................................. 79 Fitzroy .................................................................................................................................. 82 Seagrass cover and composition......................................................................................... 83 Seagrass reproductive health .............................................................................................. 87 Seagrass tissue nutrients ....................................................................................................