Survey indicates strong support for Kimberley coast protection

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By Murdoch University News

Research indicates strong public support for protecting and conserving much of the Kimberley coastline according to a report for WAMSI’s Kimberley Marine Science Program.

Murdoch University scientist Dr Jennifer Strickland-Munro and her research team conducted an online survey of more than 370 people to find the majority placed a high value on conservation and protection across the coast, including sites not covered by Marine Protected Areas (MPAs). Increased Aboriginal management was also highly valued.

 

“The survey results should be considered in the future planning strategies and management of the Kimberley coast and marine environment,” Dr Strickland-Munro said.

Two marine parks have been established along the coast; at Eighty Mile Beach and Lalang-garram/Camden Sound with proposals for three more at Roebuck Bay, Horizontal Falls and North Kimberley.

The Kimberley MPAs are managed for multiple uses including biodiversity conservation, Aboriginal culture and heritage, nature-based tourism, commercial fishing and aquaculture, science/education, recreation and recreational fishing.

The survey asked respondents to place markers on a map to show the coastal and marine areas they valued along with their management preferences for the region. The results showed there were no unvalued places along the entire Kimberley coast.

Figure 2: Responses across the different value categories. Subsistence included food, collection

 

“We also found that pro-conservation preferences dominated, but significant differences in responses suggest the potential for conflict over future management,” Dr Strickland-Munro said.

Fifteen per cent of the preferences mapped in the survey were pro-development, with resource related preferences supporting commercial fishing, new port and oil and gas developments.

Many value and preference hotspots were located outside the existing and proposed MPAs, including the northern tip of the Dampier Peninsula, the Buccaneer Archipelago and King Sound near Derby.

Figure 3: Hotspot map for values relating to the ‘physical landscape’.  Numbers are the frequency for ‘physical landscape’ values. The location of hot spots varied according to value type. However, Roebuck Bay, the western and northern coastal fringes and marine environments of Dampier Peninsula, the Buccaneer Archipelago, Horizontal Falls and Talbot Bay, and Montgomery Reef appeared as hot spots for a number of values. Sites northward of this also appeared as hotspots, although of less intensity than other area.

 

“Our findings reinforce the importance of taking a broader, comprehensive and regional view to marine conservation,” Dr Strickland-Munro said.

“In Australia, as elsewhere in the world, marine and coastal management have struggled to include diverse values, knowledge systems and cultural contexts,” she explained. “These social elements of planning are much more challenging to include compared with the biological and physical attributes of MPAs.

“MPAs can be politically-driven in their boundaries and zoning or these processes may not provide the time or resources for significant stakeholder involvement during planning phases to ensure lasting public support.

“The participatory mapping we used in our survey can be a powerful tool to help address this issue, connecting resource users, planners and managers.

“Our research contributes to marine spatial planning, which helps to identify potential conflicts among users and is particularly useful for large areas like the Kimberley that contain both State and Commonwealth jurisdictions,” Dr Strickland-Munro said.

Links:

Social values and aspirations for coastal waters of the Western Kimberley project page

Social values and aspirations for coastal waters of the Western Kimberley Report

Research Articles:

Strickland-Munro J, Kobryn H, Brown G, Moore S (2016) Valuing The Wild, Remote And Beautiful: Using Public Participation Gis To Inform Tourism Planning In The Kimberley, Western Australia International Journal of Sustainable Development and Planning DOI: 10.2495/SDP-V11-N3-355-364

Strickland-Munro J, Kobryn H, Brown G, Moore S (July 2016) Marine spatial planning for the future: Using Public Participation GIS (PPGIS) to inform the human dimension for large marine parks Marine Policy DOI: 10.1016/j.marpol.2016.07.011

Pearce J, Strickland-Munro J, Moore S (June 2016) What fosters awe-inspiring experiences in nature-based tourism destinations?, Journal of Sustainable Tourism, DOI: 10.1080/09669582.2016.1213270

Brown G, Strickland-Munro J, Kobryn H, Moore S (Dec 2015) Stakeholder analysis for marine conservation planning using public participation GIS Applied Geography DOI:10.1016/j.apgeog.2015.12.004

The $30 million Kimberley Marine Research Program is funded through major investment supported by $12 million from the Western Australian government’s Kimberley Science and Conservation Strategy co-invested by the WAMSI partners and supported by the Traditional Owners of the Kimberley.

 

Category:

Kimberley Marine Research Program

Tide turning for Kimberley crocodiles

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By Kandy Curran, Roebuck Bay Working Group

An audience of more than 100 people at the latest Science on the Broome Coast series were surprised to hear the tide is turning in different directions for the two species of crocodiles in the Kimberley region.

CSIRO freshwater crocodile biologist Dr Ruchira Somaweera, and Parks and Wildlife estuarine crocodile scientist Dr Andrew Halford, presented their research findings at the University of Notre Dame campus on September 20, 2016.

Whilst Dr Somaweera predicts a likely severe decline in freshwater crocodile numbers in some parts of the Kimberley with the invasion of cane toads, Dr Andrew Halford’s research shows estuarine crocodile numbers increasing steadily since full protection in 1997.

Freshie hatching (Photo: Ruchira Somaweera)

Dr Somaweera said that although cane toads are the biggest threat to freshies, other threats include invasive weeds such as exotic passionfruit vine that can choke river bank nesting habitats, bycatch in fishing, and predation by their saltwater relatives.

Two studies in the Northern Territory along the Daly and Victoria River systems showed significant  population declines (77% and 60% respectively), highlighting the concern for the Kimberley freshie.

Dr Somaweera said there is hope however for Crocodylus johnstoni. Recent studies show freshwater crocodile hatchlings are intelligent and can develop a taste aversion for toxic toads if they experience a non-fatal experience from eating a juvenile that has made them ill.

Dr Ruchira Somaweera presenting at Science on the Broome Coast

“I think we will see a phase of severe decline, and then those that have adapted will form a stronger population,” Dr Somaweera said.

Dr Halford is finding a steady increase in numbers of larger saltwater crocodiles as the population matures over time. Surveys conducted along the Roe and Prince Regent Rivers show a significant increase in the population of ‘salties’.

“Numbers (of saltwater crocodiles) are up in the range of a 100 to 300 per cent increase since 1997 – when their numbers were estimated to be as low as 2,500,” Dr Halford said. “It’s been 30 years, so it’s a very clear example of what happens when you take human predators out of the equation.”

Dr Halford said that increased population density is forcing younger males to move south, hence the increase in sightings around Broome in recent years. It’s not clear if these animals will establish breeding populations around Broome and further south as this will depend on the availability of suitable nesting habitat.

Freshie taking off (Photo: Ruchira Somaweera)

 

The Science on the Broome Coast series is hosted by the Roebuck Bay Working Group and Yawuru Land and Sea Unit in Broome, and sponsored by Inspiring Australia, Rangelands NRM through the Federal Government Landcare program, State NRM through Royalties for Regions, Western Australian Marine Science Institution, Department of Parks and Wildlife and University of Notre Dame Broome.

 

Category:

Kimberley Marine Research Program

Life in the mud attracts global travellers

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By Kandy Curran, Roebuck Bay Working Group

Professor Theunis Piersma’s footprint on the mudflats of Roebuck Bay and Eighty Mile Beach will go down in scientific history, for 20 years of continuous research of the wetland’s remarkable migratory shorebirds and rich invertebrate life. 

Recognising the critical importance of the benthic fauna from his base at the NIOZ Royal Netherlands Institute of Sea Research, Professor Piersma made the long journey to the remote town of Broome in 1996, to see the Ramsar listed wetlands for the first time. 

Speaking at the Science on the Broome Coast series on October 6, 2016, Professor Piersma presented findings from this research, including disturbing news of the alarming population decline in migratory shorebirds using the East-Asian Australasian Flyway.

Pebble crab (family Leucosiidea) © Kandy Curran

As Professor Piersma explained, ‘a benthic invertebrate dataset is being amassed from the results of monthly mud sampling Roebuck Bay since 1996 (in collaboration with Broome Bird Observatory and Parks and Wildlife Yawuru joint management team), and from major benthic mapping expeditions in 1997, 2002, 2006 and 2016, where volunteers and scientists sieved mud from 2,000 locations, turning up a staggering 50,000 invertebrates.

Incredibly, colourful topshells, tiny mudwhelks and snails can reach an abundance of 3,000 per square metre in Roebuck Bay’s intertidal mudflats. Bivalves are plentiful too, with more than 30 different species. Surprisingly though, the most abundant and diverse animals are worms. Some of these remarkable benthic invertebrates are superfoods for migratory shorebirds, replenishing fat stores for their annual life cycle along the flyway.

 

The benthic expedition underway on Roebuck Bay’s remarkable intertidal mudflats. © Kandy Curran

 

Australia however, is only one of nine flyways of the world under growing pressure. In 2006, Professor Piersma procured international funding to establish the non-profit Global Flyway Network to better understand and help conserve migratory shorebirds in a rapidly changing world. Through the Global Flyway Network, Broome ornithologists are employed to conduct shorebird research on Roebuck Bay, Eighty Mile Beach and at the migratory shorebird’s staging grounds on China’s Yellow Sea.

Sadly, these studies are showing a significant decline in populations of migratory knots and godwits. Professor Piersma says, ‘My hypothesis from a large data set, is that habitat loss and environmental degradation of the Yellow Sea mudflats is the key factor in this downward spiral.’

 A world leader in wetland and waterbird ecology, with a long list of prestigious scientific awards, publications and books, Professor Piersma’s  take home message is, ‘Don’t take Roebuck Bay for granted, since this remarkable embayment has the richest intertidal mudflats in the world’.

The Science on the Broome Coast series is hosted by the Roebuck Bay Working Group and Yawuru Land and Sea Unit in Broome, and sponsored by Inspiring Australia, Rangelands NRM through the Federal Government Landcare program, State NRM through Royalties for Regions, Western Australian Marine Science Institution, Department of Parks and Wildlife and University of Notre Dame Broome.

Read more about the Roebuck Bay benthic survey here.

Grant Pearson, Randal Tabrizian, Kandy Curran, Professor Theunis Piersma © Kandy Curran

Category: 

Kimberley Marine Research Program

New survey allays fears about coral reef health in the inshore Kimberley

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Only six months after one of the worst summers in history for coral bleaching, a new coral reef biodiversity and health survey suggests some of Australia’s most biologically important fringing reef communities in the central Kimberley remain intact.

READ MORE

 

Category: 

Kimberley Marine Research Program

What do flatback turtles in NW Australia eat?

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Surprisingly, little is known about what flatback turtles eat and what we do know comes from examining the stomach contents of dead flatback turtles. 

The Department of Parks and Wildlife has joined forces with WAMSI to try to answer this question through a 17 day field campaign to flatback turtle foraging grounds in the little known and relatively pristine tropical waters of north-west Australia’s remote Kimberly region.

Read More at: http://northwestatlas.org/node/1665

Category: 

Kimberley Marine Research Program

Blueprint for Marine Science Report – September 2016

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Western Australia’s marine science, government, industry, conservation and community sectors met at the inaugural Blueprint for Marine Science Forum in Perth to begin building an Australian-first collaboration around marine science.

For more information, click the following link: http://www.marinescienceblueprint.org.au/latest-progress/wa-marine-science-strategy-achieves-unprecedented-collaboration

DSN Report 4.3: Corals of the northwest of Western Australia: biogeography and considerations for dredging-related research

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WAMSI dredging science research has delivered the first guide to the choice of coral species for laboratory experiments to determine the effects of dredging activities on adult and juvenile corals in Western Australia.

Identifying scientifically appropriate coral species that will help to determine the overall ecosystem response to dredging-related pressures is one of three key research areas under the WAMSI Dredging Science Node, along with studies into primary producers such as seagrass and algae, and filter feeders such as sponges.

In Australia, and especially in sub-tropical and tropical north-western Australia, there are many examples of current and planned major dredging projects where millions of cubic metres of sediments require removal. These volumes are significant by global standards and since the released sediments can reduce or block light, clog filtering and feeding apparatus and smother benthic organisms they carry a significant environmental risk.

At the Australian Institute for Marine Science’s National Sea Simulator (SeaSim) laboratory in Townsville, Queensland, researchers are able to ‘pressure test’ for ecological responses. And so the criteria for identifying the best type of coral from the WA coast to test not only had to prove to work well under laboratory conditions but also be readily available for collection from the SeaSims lab doorstep, the Great Barrier Reef (GBR).

In order to identify which corals best fitted the criteria to achieve the most useful results the biogeographic distribution of hard corals was examined over ~2,500 km from Ashmore Reef (12°S) in the Timor Sea to the Recherche Archipelago near Esperance (34°S).

Using data mainly from studies conducted in association with the Western Australia Museum, together with digital records from the east coast held by the Museum of Tropical Queensland ~3,500 records were grouped to 19 locations and then sorted according to family, genus and species.

Of the WA records, the total hard coral species count was 361 species from 17 Families and 83 genera. The highest species count (253 species) was recorded at Scott Reef (North and South Scott Reef and Seringapatam Reef).

Another important criterion was that the corals were reasonably abundant, not just for collecting/permitting purposes but because they are an important part of the species in that habitat.

(Source: Jones R,  Corals of the north west of Western Australia: biogeography and considerations for dredging-related research)

Nine coral species were selected for study Each of these species is found in the central GBR and at each of the sites from Shark Bay to Ashmore Reef and Cartier Islet (i.e. the tropical/reef building territories).

The species represent five families including Poritidae and Acroporidae which are abundant in the Pilbara and commonly used in tagged-coral monitoring program in the Pilbara (Hanley 2011) and in the central GBR (Jones 2008).

The selected species have a range of forms and structures (morphologies):

  • Acropora millepora which “broadcast spawn” by releasing gametes—eggs and sperm—into the water to spread offspring. Broadcasters represent the majority of all reef-building corals.
  • Pocillopora damicornis is a brooder, which are most often not reef-building. Brooders release only sperm, which is negatively buoyant, sinking on to the waiting egg carriers.
  • Acropora tenuis is also a broadcast spawning species but it spawns just after sunset a few hours earlier than A. millepora allowing for more experiments to be performed on the night of spawning. It is a very common species with a similar widespread distribution pattern as Acropora millepora.

Both Pocillopora damicornis and Acropora tenuis will also be used in DSN studies (Theme 7) to help manage the risk of dredging projects around coral reefs where many (though not all) coral species spawn at predictable times of the year.

Links:

Background:

The Western Australian Marine Science Institution is delivering one of the largest single-issue marine research programs in Australia. It will vastly improve the planning and regulation of major dredging operations in our precious marine environment.

This world-class marine research is enhancing capacity within government and the private sector to predict and manage the environmental impacts of dredging in Western Australia. The outcomes will increase the confidence, timeliness and efficiency of the assessment, approval and regulatory processes associated with dredging projects.

The WAMSI Dredging Science Node is made possible through $9.5 million invested by Woodside, Chevron and BHP as environmental offsets. A further $9.5 million has been co-invested by the WAMSI Joint Venture partners, adding significantly more value to this initial industry investment. The node is also supported through critical data provided by Chevron, Woodside and Rio Tinto Iron Ore.

Category:

Dredging Science

DSN Report 3.1.3: Numerical modelling of dredge plumes: a review

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Quantifying and modelling the transport and fate of debris from dredging operations is essential to predicting the environmental impact of large-scale port and coastal developments. Now a ground-breaking project to deliver one of the largest single-issue marine research programs in Australia has brought together the world knowledge on modelling the size, extent and behaviour of dredging debris to determine the most reliable science-based results achieved to date.

In this Western Australian Marine Science Institution (WAMSI) Dredging Science Node (DSN) report, modelling exercises to simulate dredge plume dispersal conducted for Environmental Impact Assessments (EIAs) were reviewed for the tropical Australian marine environment.

Relatively speaking, protocols for hydrodynamic and wave modelling have been well established, however this is not the case for sediment transport modelling due to the more complex nature of sediment transport processes and lack of data, which is a huge obstacle for improving model predictions. The report found the following need to be considered:

  • Lack of suitable data for model calibration and validation;
  • Three dimensional models are more expensive but preferable to two dimensional models as the vertical structure of the plumes can be simulated; and
  • If the dredge plume is likely to travel to areas that are under the influence of large-scale currents, it is recommended to either set up nested models or appropriate open boundary conditions.

Compared to hydrodynamic and wave modelling, sediment transport modelling has many challenges. Some major issues  reported by this review include:

  • Modelling non-cohesive sediments (sand) and cohesive sediments (mud) requires different approaches;
  • Sediment transport models are often not calibrated or validated due to the lack of relevant field data;
  • Parameters used in sediment transport models are often not reported in EIA documentation leaving considerable uncertainty in assessing the model performance;
  • Currently sediment transport modelling in EIA documents does not include ambient sediments. Their dynamics could be important in determining the overall impact of dredging; and
  • Assessing the long-term impact of dredging requires the modelling of extreme events such as tropical cyclones and floods.

One of the main objectives of the WAMSI DSN is to promote the use of best practices in numerical modelling. This latest review of current knowledge in EIA modelling, led by CSIRO researcher Dr Chaojiao Sun, is a first step towards establishing detailed and specific guidance with regard to modelling physical and sediment transport processes in tropical and subtropical Australia, including model calibration and set up, and potential ranges of suitable parameters when possible.

Links:

 

Background:

The Western Australian Marine Science Institution is delivering one of the largest single-issue marine research programs in Australia. It will vastly improve the planning and regulation of major dredging operations in our precious marine environment.

This world-class marine research is enhancing capacity within government and the private sector to predict and manage the environmental impacts of dredging in Western Australia. The outcomes will increase the confidence, timeliness and efficiency of the assessment, approval and regulatory processes associated with dredging projects.

The WAMSI Dredging Science Node is made possible through $9.5 million invested by Woodside, Chevron and BHP as environmental offsets. A further $9.5 million has been co-invested by the WAMSI Joint Venture partners, adding significantly more value to this initial industry investment. The node is also supported through critical data provided by Chevron, Woodside and Rio Tinto Iron Ore.

Category: 

Dredging Science

DSN Report 3.1.2: Sediment transport processes within coral reef and vegetated coastal ecosystems: a review

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As part of one of Australia’s biggest scientific efforts towards minimising the impact of dredging related operations Dredging Science Node researchers have, for the first time, reviewed the current state of knowledge and gaps required to predict sediment transport within coral reef and vegetated coastal ecosystems.

Coral reefs, seagrass meadows and mangrove forests are ecologically-important and prominent features along Australia’s coastline, and considered to be particularly sensitive to dredging-related pressures. The potential for adverse impacts from exposure to suspended sediment plumes is well known; in turbid waters, a higher concentration of suspended sediment reduces light availability for photosynthesis and can clog feeding mechanisms. Indeed, the ecological function of marine biological communities exposed to sediment plumes from dredging or other activity (e.g. river inputs, cyclones, shipping and trawling) can be greatly compromised. As a result, these ecosystems are often prioritised in dredging monitoring and management programs.

These coastal ecosystems contain large and complex bottom roughness (or canopies) on the seafloor that can dramatically influence both near-bed water movement, and in turn, how sediment is transported.  However, modern sediment transport theory and models, including those used to predict the impact of dredging plumes, are still based entirely on the mechanics of how sediment is transported over open (bare) sediment beds.


(Source: Lowe R, Ghisalberti M: Sediment transport processes within coral reef and vegetated coastal ecosystems: a review)

Although many knowledge gaps still remain, the review looked at the existing framework for predicting flows within the canopies present in coastal ecosystems and how this can serve as a foundation for developing new sediment transport models that are applicable to these environments. Specifically it reviewed:

  • The traditional approaches and models used to predict near-bed sediment transport in the coastal ocean;
  • The unique hydrodynamic interactions of currents and waves with submerged canopies, and why traditional engineering approaches fail
  • Existing observations of sediment transport within aquatic vegetation and over coral reefs;
  • Measurement techniques for quantifying and monitoring near-bed sediment changes in coastal canopies; and
  • Prospects for improving predictions for the fate and transport of natural and dredging-derived sediments in these environments.


(Source: Lowe R, Ghisalberti M: Sediment transport processes within coral reef and vegetated coastal ecosystems: a review)

Based on this review, the following issues were considered important when making predictions of dredging impacts in these environments:

  • Detailed habitat maps prior to dredging projects should be used to assess potential biological impacts and the role that habitat type may have on sediment transport and where it deposits.
  • Within benthic ecosystems such as coral reefs and seagrasses, sediments are usually biogenic-derived (comprised of calcium carbonate) with physical characteristics that differ substantially from traditional siliciclastic sediments in coastal systems. Suspended sediment monitoring instrumentation may show very different responses to carbonate sediments and instrument calibration should be conducted with in situ water samples obtained on a site-by-site basis.
  • At present there are still major knowledge gaps in how the varied bottom roughness of natural coastal ecosystems controls sediment transport rates.
  • Due to this large uncertainty in sediment transport rates over benthic (seabed) canopies, model predictions over areas that include coral reefs and aquatic vegetation should be treated with extreme caution.

The report concludes, it is clear that new observations of sediment transport within environments such as coral reefs and seagrass meadows are needed to:

  1. provide the missing quantitative insight needed to better understand these processes;
  2. incorporate these dynamics into new predictive sediment transport formulations applicable to these environments; and
  3. finally embed these dynamics in process-based numerical models that can eventually be applied within predictive models.

Links:

Background:

The Western Australian Marine Science Institution is delivering one of the largest single-issue marine research programs in Australia. It will vastly improve the planning and regulation of major dredging operations in our precious marine environment.

This world-class marine research is enhancing capacity within government and the private sector to predict and manage the environmental impacts of dredging in Western Australia. The outcomes will increase the confidence, timeliness and efficiency of the assessment, approval and regulatory processes associated with dredging projects.

The WAMSI Dredging Science Node is made possible through $9.5 million invested by Woodside, Chevron and BHP as environmental offsets. A further $9.5 million has been co-invested by the WAMSI Joint Venture partners, adding significantly more value to this initial industry investment. The node is also supported through critical data provided by Chevron, Woodside and Rio Tinto Iron Ore.

Category:

Dredging Science

DSN Report 2.1: Generation and release of sediments by hydraulic dredging: a review

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The potential for adverse impacts on seabed habitats from exposure to suspended sediment plumes is now a world-wide concern. This report presents a review of available knowledge relating to Western Australian waters in order to improve the ability to estimate and predict the characteristics of dredge generated sediments.

More sepcifically, the review compared knowledge in three areas: the generation of particle size characteristics when soil or rock material is subjected to dredging processes; the rates and distributions of dredge-induced sediment resuspension; and the early stages of dredge plume development.

When soil and rock material is disturbed by marine dredging activities some of it is released as particles into the water column and transported away from the source by currents, giving rise to suspended sediment plumes. These plumes are characterised by above-normal concentrations of sediment both suspended in the water column and settled on the seabed.

In more turbid waters, the higher concentration of suspended sediment reduces visibility and light penetration through the water column. Marine biological communities that are exposed to sediment plumes from dredging activity may therefore experience ecological impacts. It’s important to recognise however, that there are other factors (e.g. river inputs, cyclones, shipping and trawling activities) in addition to dredging which have the potential to resuspend sediments and increase turbidity.

Benthic primary  producer  habitats  are  seabed communities  within which algae (e.g. macroalgae, turf and benthic microalgae), seagrass, mangroves, corals or mixtures  of  these  groups  are  prominent.* Tropical seagrasses, for example, are important habitats for marine turtles and dugongs who use them for both a direct and indirect food source.

Sediment transport models have been used in recent years to predict the trajectory, extent and intensity of dredge plumes and to support ecological impact prediction and proactive management of dredging projects.

These dredge plume models require the input of suspended sediment source terms which specify the rates and settling characteristics of sediment particles introduced to the water column by dredging activities. The extent and intensity of the dredge plumes predicted by these models is significantly influenced by the source term specification.

The estimation or prediction of these source terms in advance of dredging has been challenging and a significant cause of uncertainty in applying dredge plume models in the context of environmental impact assessment, particularly for large capital dredging projects at locations with little or no previous dredging history.

This review focuses primarily on the generation and release of sediments by hydraulic dredgers, in particular the trailing suction hopper dredger and the cutter suction dredger. These are the two most common types of hydraulic dredgers used for major capital dredging projects in Australia.

The source term may vary greatly from one dredging case to another, since it depends on many factors, including: the nature of the in situ material to be dredged; the type and specifications of the dredging equipment; the dredging work method and dredge operating parameters; the site conditions (including bathymetry, currents and waves).

Figure 10 from Mills D, Kemps H, Generation and release of sediments by hydraulic dredging: a review – Structure of the TASS model for TSHDs (version 4.0) showing the sub-modules and underlying processes (from HR Wallingford 2013a, with kind permission from HR Wallingford and Ecoshape).

The report highlights that it is important that dredge-induced sediment suspension data sets are collected according to agreed protocols and methods (several of which are referenced in the report) so that calculations from these data sets can be reliably ranked and compared.

Overall, the number of these data sets has increased significantly in recent years. However many of these are not publicly available and their availability (and potential use) is restricted. Also, there are some relatively common dredging situations (e.g. trailing suction hopper dredging with low under keel clearance) that are not well represented by the available data sets.

The acquisition of high quality data sets, from both full-scale dredging operations and laboratory experiments, also leads to an improved understanding of the physical processes involved in the generation and release of dredged material particles and the early stages of plume formation. This enables the development of process-based source models as an additional means of estimating source terms, and this report reviews these models.

This report responds to Task 2.1 of the WAMSI Dredging Science Node Science Plan (Masini et al. 2011) which is to review  the  state  of  knowledge  regarding  the characteristics of  dredge-generated sediments,  considering  the  application  of  that  knowledge  to  Western  Australian settings.

*Environmental Assessment Guideline No. 3 (December 2009) Protection of Benthic Primary Producer Habitat

Links:

Background:

The Western Australian Marine Science Institution is delivering one of the largest single-issue marine research programs in Australia. It will vastly improve the planning and regulation of major dredging operations in our precious marine environment.

This world-class marine research is enhancing capacity within government and the private sector to predict and manage the environmental impacts of dredging in Western Australia. The outcomes will increase the confidence, timeliness and efficiency of the assessment, approval and regulatory processes associated with dredging projects.

The WAMSI Dredging Science Node is made possible through $9.5 million invested by Woodside, Chevron and BHP as environmental offsets. A further $9.5 million has been co-invested by the WAMSI Joint Venture partners, adding significantly more value to this initial industry investment. The node is also supported through critical data provided by Chevron, Woodside and Rio Tinto Iron Ore.

Category:

Dredging Science