The $19 million Western Australian Marine Science Institution (WAMSI) Dredging Science Node has delivered one of the largest single issue environmental research programs in Australia. This world-class research will vastly improve the planning and regulation of major dredging operations in Western Australia, nationally and internationally.
Perhaps no other environmental issue has been subject to more public debate and controversy in WA over the past decade than the potential impacts on our sensitive marine environment of dredging associated with construction and expansion projects in the mining, energy and port sectors.
The WAMSI project has been a remarkable collaboration between industry, government and research resulting in the unprecedented sharing of hundreds of millions of dollars’ worth of environmental monitoring data collected during four large-scale dredging projects (Pluto, Cape Lambert, Gorgon and Wheatstone) and provided by Chevron, Woodside and Rio Tinto Iron Ore.
Using in-depth analysis and applied science the project has delivered outputs that will be directly applied to improve the social, environmental and financial outcomes of major marine dredging activities, most notably in the form of improved Environmental Impact Assessment guidelines.
The outcomes are already finding valuable applications in the assessment of current marine dredging proposals in Western Australia and elsewhere, leading to greater confidence for government and industry and delivering practical and real ways to better protect and manage our marine environment.
The WAMSI Dredging Science Node has been made possible through $9.5 million invested by Woodside, Chevron and BHP as environmental offsets and a further $9.5 million co-invested by the WAMSI Joint Venture partners.
Review and consolidation of available environmental data collected for dredging projects.
Predicting and measuring the characteristics of sediments generated by dredging, plus characterisation and prediction of dredge-generated sediment plume dynamics and fate.
A review of available knowledge on the generation of particle size characteristics when material is subjected to dredging processes, dredge-induced sediment resuspension and the early stages of dredge plume development.
A review of contemporary practice in the context of Environmental Impact Assessment in Western Australia.
A review of the potential of remote sensing to support dredge plume monitoring, and the availability of existing in situ data that may support further research into the development and validation of applicable remote sensing products.
In this review we summarise the current state of knowledge and gaps in the various components required to predict sediment transport within coral reef and vegetated coastal ecosystems.
This review provides a synthesis of the current knowledge on several key processes for sediment transport modelling, and standard practice of sediment transport modelling around the world.
A field program was undertaken during a large scale capital dredging program near Onslow, northwestern Australia (the Wheatstone Project) to collect in situ total suspended solids (TSS) concentration and coincident optical data. These data have been used to develop and test relationships between surface reflectance and TSS.
Comparative measurements using various common turbidity sensors, including optical scattering and acoustic scattering instrumentation
The aim of this project was to build on ‘conventional’ knowledge of sediment transport over bare sandy beds to develop new transport formulations.
The project sought to improve the modelling of the dynamics and fate of total suspended solids (TSS) in the passive dredge plumes.
There is a critical need to establish quantitative relationships between dredging-relating pressures and the responses for key biota.
Information from several major dredging projects was used to describe sediment particle sizes in the water column/seabed.
Establishing an evidence-based footprint of water quality impacts associated with dredging is clearly important for a range of stakeholders.
Smothering of benthic organisms by high levels of sediment deposition is known to be one of the key cause-effect pathways associated with dredging activities.
Design, calibration, laboratory testing, and then subsequent field deployment of an in situ optical backscatter (OBS) sediment deposition sensor.
To guide the choice of coral species for the laboratory experiments on the effects of dredging activities on adult and juvenile corals, the biogeographic distribution of hard corals in Western Australia was examined.
The exposure conditions used in these studies were based on the recent detailed studies of spatial and temporal patterns of dredging plumes from several large scale capital dredging projects.
Baseline data on demographic processes to improve our understanding of the fundamental population dynamics in relation to recruitment, growth and survival of reef building corals in the Pilbara.
The function and biological role of the mucous sheet has been previously explored, yet studies involving exposure to altered environmental conditions have produced equivocal results.
A three-part report including analysis of the Barrow Island coral health data set.
Through a combination of laboratory and field experiments, plus field surveys, this theme determines the levels of dredging-related pressures that produce the earliest observable effects on two species of seagrasses considered most ecologically important in the northwest of Western Australia.
This review summarises our understanding, from a northwest of Western Australia and global perspective, the pressures seagrasses are exposed to from dredging, their tolerance thresholds and responses to dredging related stressors, and the bioindicators of dredging related stressors.
This review was undertaken to identify which seagrass primary producers (species or different functional groups) that collectively cover the bio-geographic range of key primary producers in the northwest of Western Australia are most appropriate for the focus of subsequent research into thresholds and indicators of response to dredging-related pressures
This study was the first of its kind to examine the patterns of genetic diversity in seagrasses in the Pilbara region of WA.
This study was undertaken to improve our understanding of the spatial and temporal patterns in seagrass composition, abundance and reproductive phenology in the Pilbara.
Examining the capacity, duration and mechanisms of recovery of seagrass from a severe localised disturbance.
This report presents findings from a controlled burial experiment that aimed to determine the effects of burial by sediments on the growth of two seagrass species.
This report presents findings from a controlled light experiment that aimed to determine the effects of low light stress on the growth of three seagrass species.
This report presents findings from a controlled mesocosm experiment that aimed to determine the responses of seagrasses to, and recovery from, differences in the pattern of the delivery of light.
Seagrasses can be negatively affected by dredging-associated deterioration in water clarity due to suspended sediments and burial by the subsequent deposition of those sediments. This report presents findings from a controlled sediment burial experiment.
Extensive dredging projects pose an environmental risk to local filter feeder communities through turbidity and light reduction, impediments to filtration organs and smothering by sedimentation. This project aimed to investigate the nature and thresholds of such risks.
This review generated an enhanced understanding of shorter-term physiological and longer-term ecological responses of filter feeders to sediment and mechanical effects of dredging gear, and has identified physiological and ecological indicators for use in future work.
This study presents information on the biodiversity of sponges in marine environments off northwest Western Australia.
Changes in turbidity, sedimentation and light over a two year large scale capital dredging program at Onslow, northwestern Australia, were quantified to assess their effects on filter feeder communities, in particular sponges.
Results of these individual experiments contributed to the derivation of trigger values that can be used to interrogate models for impact prediction and in water quality monitoring programs to alert dredging proponents to levels of stressors that, if continued, could detrimentally impact sponge populations.
This project aimed to address the environmental effects of sediments on the early life-history stages of corals, coral spawning Environmental Windows and shutdown procedures as applied to large-scale dredging projects in WA.
This review examines the effects of turbidity on all aspects of the coral life cycle of corals from gamete development to the early post settlement stage. The focus is on the effects of sediments on broadcast spawning species which usually dominate the tropical coral reef environment.
This review provides a brief summary of the methods and sampling protocol for quantifying patterns of reproduction in corals and an approach to quantifying the relative significance of periods of reproductive output that may occur throughout the year.
All biologically plausible cause-effect pathways whereby sediment could affect the four broad life phases were identified. A series of experiments were designed and conducted to validate the pathways and determine pressure-response relationships.
Dredging can have significant impacts on aquatic environments, but the direct effects on fish have not been critically evaluated. Here, a meta-analysis is used to understand how dredging-related stressors directly influence the effect size and the response elicited in fish.
This study reviewed environmental windows for organisms other than corals and fish such as sessile invertebrates, macroalgae and seagrasses. Environmental windows are periods of critical importance to the life history of a marine species, like reproduction and recruitment.
August 10, 2021
Perth-based environmental and oceanographic consultancy, O2 Marine attributes Western Australian Marine Science Institution (WAMSI) dredging science research as a key factor that contributed to its rapid organic growth and business success.
November 17, 2020
CSIRO has released a new guideline that provides current best practice for dredge plume modelling in the context of Australia’s Environmental Impact Assessment processes.
September 9, 2019
