Candidate Bioindicator Measures to Monitor Exposure to Changing Water Quality on the Great Barrier Reef

Research Report

Katharina Fabricius¹, Sven Uthicke¹, Tim Cooper^1,2, Craig Humphrey¹, Glenn De'ath¹ and Jane Mellors³

¹Australian Institute of Marine Science
²James Cook University
³Queensland Department of Primary Industries and Fisheries

Catchment to Reef Joint Research Programme of the CRC Reef Research Centre and Rainforest CRC

ISBN 9781921359026
Published August 2007

Preface

This Interim Report summarises research results aimed at identifying sensitive and cost-effective indicators to monitor changes in biota in the inshore Great Barrier Reef (GBR) in response to changing water quality from altered catchments.

Through the Great Barrier Reef Water Quality Protection Plan, the National Action Plan (NAP) for Salinity and Water Quality and National Heritage Trust (NHT2), the Commonwealth and Queensland Governments proposed to assist landholders in the Great Barrier Reef catchment to reduce terrestrial runoff of sediment and nutrients to the reef.  The main aim of the 'Reef Plan' is to 'halt or reverse the decline in water quality entering the GBR' by 2013.  As rivers are the most important sources of new nutrients and sediments entering the lagoon, a reduction of river loads should, in the long term, prevent further deterioration of the water quality within the GBR lagoon.  The importance of the actions proposed through the 'Reef Plan' have recently been further emphasised by new models that show that dissolved nutrients discharged from the Burdekin River mouth may be retained in the GBR lagoon by physical processes alone for up to one year.  Biological uptake could further slow down dissipation, resulting in exposure times of reef organisms to land-sourced materials that are ecologically relevant.

Developing the capacity to reliably monitor the status in nearshore marine ecosystems in response to changing water quality is an essential part of the Reef Plan.  This report presents preliminary results of research aimed at identifying the most suitable biophysical indicators to identify and track such changes.  It was conducted as a Task of the Catchment to Reef Program (January 2004 - June 2006), a supplementary program to the Cooperative Research Centre for the Great Barrier Reef World Heritage Area (CRC Reef Research Centre) and the Cooperative Research Centre for Tropical Rainforest Ecology and Management (Rainforest CRC).  This report also builds on and incorporates elements of previous work carried out through the CRC Reef Task Terrestrial Runoff:  Inputs and Impacts (July 2000 - June 2006), and ongoing research activities at the Australian Institute of Marine Science, which produced a review of a number of related studies assessing the effects of terrestrial runoff on individual groups of ecosystem properties.