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Internet surveys are becoming an increasing popular survey collection method because collection times are quicker and survey costs are lower than other collection techniques. Many studies have been conducted overseas to compare the effects of survey collection modes with results still remaining inconsistent. Fewer studies have compared collection methods for nonmarket valuation surveys, particularly for the more complex stated preference, choice modelling surveys. In this study, a comparison of internet and paper-based surveys is made to determine if the results for overseas studies can be replicated in Australia. The valuation exercise elicited values from Brisbane respondents for future improvements in the environmental condition of the Great Barrier Reef. The results indicate that there were some socio-demographic and attitudinal differences between the two samples and the models developed to explain the influence on choice selection were also significantly different. However, no differences in value estimates were found in the final results; household willingness-to-pay for an improvement in the condition of the GBR was equivalent across collection methods. [ABSTRACT FROM AUTHOR]

The paper 'Biodiversity values of remnant freshwater floodplain lagoons in agricultural catchments: evidence for fish of the Wet Tropics bioregion, northern Australia', published in Aquatic Conservation: Marine and Freshwater Ecosystems in 2015, has contributed in several ways to the integration of freshwater wetland science within new catchment management policies and practices for Great Barrier Reef (GBR) sustainability.The Tully–Murray biodiversity study developed novel protocols to sample larval, juvenile, and adult fish life‐history stages in floodplain lagoons using a combination of boat‐based backpack electrofishing and fyke netting. In addition, hydrological and hydrodynamic models were applied in a completely new way to quantify the timing, extent, and duration of water connectivity across floodplain streams, cane drains, and wetlands. Combining the two novel approaches enabled an analysis of lagoon fish assemblage patterns in relation to environmental gradients, especially floodplain hydrology, connectivity patterns, and measures related to agricultural land use.In demonstrating the importance of different levels of connectivity for different biodiversity outcomes in freshwater floodplain lagoons of the Tully–Murray catchment, the subject paper established that floodplain connectivity needs to be taken into consideration in wetland management practices.The timing of the subject publication was fortuitous. It coincided with the preparation of the evidence‐based 2017 Scientific Consensus Statement on land‐based water quality impacts on the GBR. As one of the few freshwater wetland ecology publications for the catchments of the GBR at that time, this paper played an important role in demonstrating freshwater wetland values, fish conservation options, and management imperatives to sustain wetland ecological health and services in GBR catchments.By advancing the understanding of factors driving biodiversity patterns, and the importance of connectivity and ecohydrological processes in freshwater floodplain wetlands of the GBR catchment, the Tully–Murray study helped to drive new policy directives for the protection and restoration of catchment, floodplain, and estuary functions, and connectivity, now embedded in the Reef 2050 Long‐Term Sustainability Plan 2018, an overarching strategy for managing the GBR over the next 35 years, and complementary Queensland environmental legislation. [ABSTRACT FROM AUTHOR]

Dependence on water is one of the factors that can determine regional vulnerability in Australia. Climate change is predicted to change rainfall patterns in the Great Barrier Reef (GBR) region, and scarce water resources have the potential to make regional Queensland economies increasingly vulnerable. Understanding which economic sectors depend on water as an input factor helps in understanding sectoral and regional vulnerability, and thus in guiding regional policy aimed at structural change. Using a regional Queensland Input-Output (IO) model, this paper integrates water consumption of the GBR region and then compares monetary IO multipliers with water consumption multipliers. We argue that these IO multipliers can inform regional decision makers about potential future regional vulnerability by taking into account limited water resources. [ABSTRACT FROM AUTHOR]

Photography is an important element of the tourist experience and provides both a method of later reliving the experiences of the journey as well as sharing elements of the journey with others. In the digital age photography has taken on a new dimension with the ability of people to enhance images as well as share them with others via new media such as the internet, Facebook, YouTube, MySpace and blogs. This paper reports on research undertaken into the taking of photographs of the Great Barrier Reef and finds that respondents rate the need for good photographic images as a high priority, are likely to use digital cameras in preference to other photographic devices, that there is a small but significant market for commercial photos and offering digital photo opportunities can provide the operator with a powerful and free marketing tool. [ABSTRACT FROM AUTHOR]

Collecting raw data from a wireless sensor network for environmental monitoring applications can be a difficult task due to the high energy consumption involved. This is especially difficult when the application requires specialized sensors that have very high energy consumption, e.g. hydrological sensors for monitoring marine environments. This paper introduces a technique for reducing energy consumption by minimizing sensor sampling operations. In addition, we illustrate how a randomized algorithm can be used to improve temporal coverage such that the time between the occurrence of an event and its detection can be minimized. We evaluate our approach using real data collected from a sensor network deployment on the Great Barrier Reef. [ABSTRACT FROM AUTHOR]

This paper proposes using an adaptive management approach to achieve water quality improvement in large catchments with multiple diffuse pollutant issues. Adaptive management involves attention to process, and commitment to continually improving knowledge and practice. It also requires an appreciation of differences in understanding of various stakeholders and an ongoing commitment to learning. Based on research with the Burdekin Dry Tropics regional Natural Resource Management group, the paper shows how the acquisition of knowledge about Water Quality Management can be an aim in itself, rather than an activity peripheral to the planning process. To this end, the paper describes the methods used to elicit stakeholders’ understandings, explores the variation in understandings between key stakeholders, and describes a process used to incorporate the various views in an adaptive management framework for managing water quality. The research findings reveal the importance of process and participation for adaptive management and suggest that success can be judged in terms of learning outcomes. [ABSTRACT FROM AUTHOR]

• i-RAT (https://i.rat-net) is an APSIM-based interactive web application for sugarcane growers. • Users can easily conduct 'what-if' analyses without needing to setup APSIM-Sugar. • It assesses the impacts of changed irrigation practices on revenue, productivity, water quality, carbon/nitrogen cycles, and greenhouse gas emissions. • i-RAT promotes sustainable technologies for enhanced irrigation practices. Water pollution and climate change are among the greatest threats to the iconic Great Barrier Reef (GBR). To improve the GBR's long-term outlook, making improvements on these fronts is required. Owing to the complex interactions between soils, climate, and farm management, a tool is needed to guide agricultural land managers about which management practice changes are more likely to deliver improved water quality and climate resilience outcomes whilst maintaining profitability. Using concepts drawn from social studies of science and technology, a 'discussion' support system (DSS) named I rrigation R apid A ssessment T ool (i-RAT) was developed through participatory processes designed to enhance co-learning from the development of this DSS. i-RAT is a rapid assessment-visualisation tool in an interactive web application (https://i-rat.net) to visualise the impacts of changed irrigation practices for sugarcane farmers and extension staff. Specifically, i-RAT compares these impacts regarding farm economics, water quality, productivity, carbon and nitrogen cycles, and greenhouse gas emission. The core of i-RAT is the sugarcane module from the Agricultural Production Systems sIMulator (APSIM) modelling platform. i-RAT was first developed for the Burdekin sugarcane growing region in Queensland (Australia's largest sugarcane producing region). Various soil types and management scenarios representing farming practices in the Burdekin region were used for simulations (1971–2021) to generate a datacube. In this paper, we describe how fundamental learnings about more (drought) resilient farming systems and more sustainable irrigation practices can be extracted from i-RAT. Details of the participatory approach with research and industry partners that informed the design and function of i-RAT and how APSIM was set up and parameterised are described. A 'what-if' analysis demonstrated the i-RAT features and application. [ABSTRACT FROM AUTHOR]

The Great Barrier Reef Marine Park was established to provide for conservation and ecologically sustainable multiple use of 344,400 km of a large marine ecosystem. Management is based on multiple use, with zoning as a fundamental component of marine spatial planning. The legislative framework, including a specific Act and Regulations, address the objectives of ecosystem-based, integrated management of human uses and impacts consistent with best contemporary understanding of biological diversity. Zoning is one of a suite of management tools that include other spatial and temporal management tools and non-spatial measures including public education, community engagement, codes of environmental best practice, industry partnerships and economic instruments. The first section of the Great Barrier Reef Marine Park came into operation in 1981 and the most recent zoning came into operation in mid 2004. The paper discusses some common misunderstandings about zoning and identifies lessons that appear relevant for others addressing management and use of marine ecosystems and natural resources. [ABSTRACT FROM AUTHOR]

Abstract: The focus of this paper is to compare different evaluation frameworks for selecting landholder proposals to improve water quality. The case study is a water quality tender performed in the Burdekin region in Northern Australia in 2007/2008 where bids could be assessed using an inputs-based best management practice scorecard or an outputs-based auction metric. The scorecard approach and other variants of multi-criteria analysis are commonly applied in grant schemes, where landholder proposals are rated by a range of inputs-based criteria. Output-based approaches are typically applied in water quality and conservation tenders, where an environmental benefits index is constructed to summarise the environmental improvements generated by each proposal. These then allow projects to be selected on the basis of cost effectiveness. The case study evaluation reported in this paper demonstrates that the input focus of multi-criteria analysis type assessments are flawed, and that the efficiency of public funding can be more than doubled using auction metrics to assess proposals for landholders to improve water quality. [ABSTRACT FROM AUTHOR]

This paper investigates the perceived well-being of residents of two coastal rural areas located in the central part of the Great Barrier Reef region in Australia. Typically, well-being studies concentrate on collating data from respondents about their perceptions of levels of satisfaction on specific predetermined points. However, recording respondents' satisfactions with various contributors to their well-being does not provide researchers with an indication of how important those contributors are to the respondents. This paper presents an approach to the analysis of well-being that combines the perceived importance of the well-being factors with the reported levels of satisfaction with the factor, aggregated to a regional level. A total of 372 individuals were asked to comment on how satisfied they were with twenty-seven well-being factors from the domains of society, the natural environment, and the economy and services. The highest reported satisfaction rates were associated with family relations, family safety, family health, family education levels, and work (>75%). Information about the perceived importance of the well-being factors was also recorded and combined with information about levels of satisfaction, thus creating an index of dissatisfaction—an index that allows one to identify an 'action list', or set of regional priorities that, if addressed by policy makers, has the potential to enhance regional well-being. Several high-scoring factors in the index, such as condition of the landscape and beaches and access to nature, came from the domain of the natural environment, indicating the importance of integrated approaches to well-being that also include environmental concerns. [ABSTRACT FROM AUTHOR]

Spatial distributions of coral reef fish species are potentially determined by habitat preferences and behavioural interactions. However, the relative importance of these factors and whether or not behavioural interactions reinforce or disrupt habitat associations are poorly understood. This paper explores the degree to which habitat and social preferences explain the association that three common coral reef cardinalfish species ( Zoramia leptacanthus, Archamia zosterophora and Cheilodipterus quinquelineatus; family Apogonidae) have with coral substrata at Lizard Island, Great Barrier Reef. At diurnal resting sites, species were strongly associated with branching corals, with 80-90% of each species inhabiting one branching coral species, Porites cylindrica. Species were also highly gregarious, forming large con-specific and hetero-specific aggregations in coral heads, potentially reinforcing habitat associations. Three-way choice experiments were conducted to test fishes habitat preferences for living coral over dead substrata, for particular coral species, and the influence of gregarious behaviour on these habitat choices. The strength of habitat preferences differed among species, with Z. leptacanthus preferring live coral and P. cylindrica, A. zosterophora preferring P. cylindrica, whether live or dead and C. quinquelineatus exhibiting no preferences. All species were attracted to conspecifics, and for C. quinquelineatus and A. zosterophora, conspecific attraction resulted in stronger preferences for live corals. Gregarious behaviour also increased C. quinquelineatus associations with P. cylindrica. The relative strength of social attraction versus habitat preferences was investigated by comparing fish habitat preferences in the presence and/or absence of conspecifics. The presence of conspecifics on non-preferred rubble habitat reduced each species association with live coral. This study's results indicate that in the field, habitat preferences and conspecific attraction combine to reinforce the association between cardinalfishes and a narrow range of coral substrata. [ABSTRACT FROM AUTHOR]

The integration of social and ecological knowledge has been identified as one of the key issues and research priorities in landscape ecology. However, research into the tools and processes that support knowledge integration for planning sustainable land- and sea-scapes is largely lacking. To fill this gap, Bohnet and Smith (Landsc Urban Plan 80:137–152, ) developed a social-ecological planning framework based on a holistic landscape concept which I applied in the Tully–Murray basin to test the framework’s transferability and effectiveness for knowledge integration in a water quality improvement planning context in the Great Barrier Reef (GBR) region, Australia. In this paper I present the context in which the Tully Water Quality Improvement Plan (WQIP) was developed, the tools and processes applied during the three planning stages to achieve knowledge integration, and the results from this exercise. I then discuss the transferability and effectiveness of the framework using criteria identified to assess collaborative planning processes, outputs and outcomes, such as collaborative science and social and political capital. While many social outcomes such as the creation of partnerships between multiple-stakeholders, including Traditional Owners, local farmers, industry, government, community groups, schools, and the wider public, have been achieved, the research also highlights some of the challenges related to multiple-stakeholder relations. Further research into the roles and responsibilities of multiple-stakeholders for knowledge integration in developing and managing sustainable land- and sea-scapes is recommended. [ABSTRACT FROM AUTHOR]

This paper describes the role of the autonomous underwater vehicle (AUV) Sirius on a research cruise to survey drowned reefs along the shelf edge of the Great Barrier Reef in Queensland, Australia. The primary function of the AUV was to provide georeferenced, high-resolution optical validation of seabed interpretations based on acoustic data. We describe the AUV capabilities and its operation in the context of the multiple systems used in the cruise. The data processing pipeline involved in generating simultaneous localization and mapping–based navigation, large-scale, three-dimensional visualizations, and automated classification of survey data is briefly described. We also present preliminary results illustrating the type of data products possible with our system and how they can inform the science driving the cruise. © 2010 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Reef corals form associations with an array of genetically and physiologically distinct endosymbionts from the genus Symbiodinium. Some corals harbor different clades of symbionts simultaneously, and over time the relative abundances of these clades may change through a process called symbiont shuffling. It is hypothesized that this process provides a mechanism for corals to respond to environmental threats such as global warming. However, only a minority of coral species have been found to harbor more than one symbiont clade simultaneously and the current view is that the potential for symbiont shuffling is limited. Using a newly developed real-time PCR assay, this paper demonstrates that previous studies have underestimated the presence of background symbionts because of the low sensitivity of the techniques used. The assay used here targets the multi-copy rDNA ITS1 region and is able to detect Symbiodinium clades C and D with >100-fold higher sensitivity compared to conventional techniques. Technical considerations relating to intragenomic variation, estimating copy number and non-symbiotic contamination are discussed. Eighty-two colonies from four common scleractinian species (Acropora millepora, Acropora tenuis, Stylophora pistillata and Turbinaria reniformis) and 11 locations on the Great Barrier Reef were tested for background Symbiodinium clades. Although these colonies had been previously identified as harboring only a single clade based on SSCP analyses, background clades were detected in 78% of the samples, indicating that the potential for symbiont shuffling may be much larger than currently thought. [ABSTRACT FROM AUTHOR]

A prerequisite for meaningful environmental legislation is that it he based upon an adequate scientific understanding of the natural system to which It is applied. In 2003, the Australian Commonwealth and Queensland State governments introduced a Reef Water Quality Protection Plan. which aimed to "improve" water quality in river catchments adjacent to the Great Barrier Reef (GRR) and in nearby coastal waters. The Plan was introduced in the absence of any substantive evidence for regional degradation of GRR water quality. This paper reviews the available data regarding nutrient contents En the Tully River, north Queensland, which is cited as the best (available) evidence for human-related changes in nutrient export from (GBR) catchment [1]. It is shown that the claim of human-related nutrient enrichment in the Tully River, and regionally, is without substance. No detectable trends in GBR water quality have occurred since systematic measurements were first started in the 1980s. Environmental policies that are based on mischievous claims of chimerical damage to the Great Barrier Reef damage the reputation of science as a tool for disinterested analysis, and provoke widespread cynicism in the community regarding the integrity of contemporary environmental politics. [ABSTRACT FROM AUTHOR]

Abstract: Adaptive management is the pathway to effective conservation, use and management of Australia’s coastal catchments and waterways. While the concepts of adaptive management are not new, applications involving both assessment and management responses are indeed limited at the national and regional scales. This paper outlines the components of a systematic framework for linking scientific knowledge, existing tools, planning approaches and participatory processes to achieve healthy regional partnerships between community, industry, government agencies and science providers to overcome institutional barriers and uncoordinated monitoring. The framework developed by the Coastal CRC (www.coastal.crc.org.au/amf/amf_index.htm) is hierarchical in the way it displays information to allow associated frameworks to be integrated, and represents a construct in which processes, information, decision tools and outcomes are brought together in a structured and transparent way for adaptive catchment and coastal management. This paper proposes how an adaptive management approach could be used to benefit the implementation of the Reef Water Quality Protection Plan (RWQPP). [Copyright &y& Elsevier]

Abstract: The Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZECC Guidelines) provide default national guideline values for a wide range of indicators of relevance to the protection of the ecological condition of natural waters. However, the ANZECC Guidelines also place a strong emphasis on the need to develop more locally relevant guidelines. Using a structured framework, this paper explores indicators and regional data sets that can be used to develop more locally relevant guidelines for the Great Barrier Reef World Heritage Area (GBRWHA). The paper focuses on the water quality impacts of adjacent catchments on the GBRWHA with the key stressors addressed being nutrients, sediments and agricultural chemicals. Indicators relevant to these stressors are discussed including both physico-chemical pressure indicators and biological condition indicators. Where adequate data sets are available, guideline values are proposed. Generally, data were much more readily available for physico-chemical pressure indicators than for biological condition indicators. Specifically, guideline values are proposed for the major nutrients nitrogen (N) and phosphorus (P) and for chlorophyll-a. More limited guidelines are proposed for sediment related indicators. For most agricultural chemicals, the ANZECC Guidelines are likely to remain the default of choice for some time but it is noted that there is data in the literature that could be used to develop more locally relevant guidelines. [Copyright &y& Elsevier]

This paper describes the challenges of mapping cyclone disturbance across vast geographic region of the Great Barrier Reef (GBR) in Australia. The paper also describes how cartographic visualization can help one understand the implications of these challenges on the quality of the results. GBR forms the largest coral reef system in the world, including nearly 3000 individual reefs that stretch for more than 2000 km along the Queensland coast and cover an area of over 348000 square kilometer. The ability to map cyclone disturbance is limited by a general lack of key data sets, as well as high levels of uncertainty in the data that is available. The article concludes that Mapping cyclone disturbance of the GBR is difficult, However, it is possible to build a predictive model of cyclone disturbance by linking field observations of reef damage from cyclones to hindcast cyclone energy and reef vulnerability measures. Creative use of cartographic visualization is essential.

The north-east Australian margin is the largest modern example of a tropical mixed siliciclastic/carbonate depositional system, with an outer shelf hosting the Great Barrier Reef (GBR) and an inner shelf dominated by fluvially sourced siliciclastic sediment wedges. The long-term interplay between these sediment components and sea level is recorded in the Queensland Trough, a 1–2 km deep N–S elongate basin situated between the GBR platform and the Queensland Plateau. In this paper, 154 samples from 45 surface grabs and six well-dated piston cores were analysed for total carbonate content, carbonate mineralogy and Sr concentration to establish spatial and temporal patterns of carbonate accumulation in the Queensland Trough over the last 300 kyr. Surface carbonate contents are lowest on the inner-shelf (<5%) and in the trough axis (<60%) because of siliciclastic dilution. Carbonate on the shelf is mostly Sr-rich aragonite and high-Mg calcite (HMC), whereas that in the basin is mostly low-Mg calcite. Once normalized to remove the effects of siliciclastic dilution, surface Sr-rich aragonite and HMC abundances decrease linearly to background levels ≈ 100 km seaward of the shelf edge. Core samples show that, over time, normalized aragonite and Sr abundances are greatest during periods of shelf flooding and lowest when sea level drops below the shelf edge. This is consistent with changes in the production of coral and calcareous algae, and the shedding of their debris from the shelf. Interestingly, normalized HMC concentrations on the slope peak during periods of major transgression, perhaps because of maximum off-shelf transport from inter-reef areas or intermediate water dissolution. After accounting for siliciclastic dilution, there are strong similarities in both spatial and temporal patterns of carbonate minerals between slopes and basins of the north-east Australian margin and those of pure carbonate margins such as the Bahamas. A limited set of basic processes, including the formation and breakdown of carbonate on the shelf, the transport of carbonate off the shelf and eustatic sea level, probably controls carbonate accumulation in slope and basin settings of tropical environments, irrespective of proximal siliciclastic sediment sources. [ABSTRACT FROM AUTHOR]

This paper investigates the use of aesthetic value as a criterion by which the significance of heritage places is assessed. It is argued that current heritage management practice has not engaged with the extensive discourse relating to aesthetics, and therefore confines aesthetics to a particular class and culture, and an inert view of only one of our sensory experiences. Historical records relating to the Great Barrier Reef are used to show how aesthetic appreciation of the area has changed over time.The data suggest that the failure to recognise an aesthetic that is primarily non-visual can lead to changes in landscape and loss of associated value. It also suggests that aesthetic values change rapidly and are influenced by social and technological factors. [ABSTRACT FROM AUTHOR]

Evidence shows that in the modern ocean, coral reefs are disappearing, and these losses are tied to climate change. However, research also shows that coral reefs can adapt rapidly to changing conditions leading some researchers to suggest that some reef systems will survive future climate change through adaptation. It is known that there were changes in the area covered by coral reefs in the past. Therefore, it is important to investigate the long-term response of coral reefs to environmental changes and high sea-surface temperatures (SSTs). However, because of diagenetic issues with SST proxies in neritic, metastable carbonate-rich environments, there is an incomplete and sometimes even incorrect understanding of how changes in SSTs affect carbonate reef systems. A good example is the Queensland Plateau offshore northeast Australia next to the threatened Great Barrier Reef. In the Late Miocene, between 11 and 7 Ma, a partial drowning caused the reef area on the Queensland Plateau to decline by ~ 50% leading to a Late Miocene change in platform geometry from a reef rimmed platform to a carbonate ramp. This reef decline was interpreted to be the result of SSTs at the lower limit of the modern reef growth window (20–18 °C). This article presents a new Late Miocene—ased SST record from the Coral Sea based on the TEX86H molecular paleothermometer, challenging this long held view. Our new record indicates warm tropical SSTs (27–32 °C) at the upper end of the modern reef growth window. We suggest that the observed temperatures potentially exceeded the optimal calcification temperatures of corals. In combination with a low aragonite supersaturation in the ocean, this could have reduced coral growth rates and ultimately lowered the aggradation potential of the reef system. These sub-optimal growth rates could have made the coral reefs more susceptible to other stressors, such as relative sea-level rise and/or changes in currents leading to reef drowning. Given that these changes affected coral reefs that were likely adapted to high temperature/low aragonite saturation conditions suggests that reefs that have adapted to non-ideal conditions may still be susceptible to future climate changes due to the interaction of multiple stressors associated with climate change. [ABSTRACT FROM AUTHOR]

The article presents a discussion of the article Synthetic Tropical Cyclone Database, by M. K. James and L. B. Mason. The authors provide a Monte Carlo technique for generating a database of synthetic tropical cyclone tracks over the Great Barrier Reef Marine Park, situated off the coast of Queensland. They confirm their synthetic tracks by comparing the marginal probability density functions of various track parameters against the Australian tropical cyclone best-track database. They conclude that their synthetic database has statistical properties that are the same to the observational record.

Simple Summary: Catch-per-unit-effort at a spearfishing competition in North Queensland, Australia was 1.25 fish per hour. Citizen scientists reported 358 sharks comprising of 10 species/groups, with 3.11 sharks observed per hour. Twelve percent of all sharks sighted in this study were regarded as potentially dangerous to humans. This is the first scientific study of shark depredation for spearfishing. C. amblyrhynchos were primarily responsible for depredation, with 5.9% of speared fish taken. Sixty percent of interviewees perceived that shark numbers have increased in the past 10 years. We developed and applied a method to quantify spearfisher effort and catch, shark interactions and shark depredation in a boat-based recreational spearfishing competition in the Great Barrier Reef Marine Park in Queensland. Survey questions were designed to collect targeted quantitative data whilst minimising the survey burden of spearfishers. We provide the first known scientific study of shark depredation during a recreational spearfishing competition and the first scientific study of shark depredation in the Great Barrier Reef region. During the two-day spearfishing competition, nine vessels with a total of 33 spearfishers reported a catch of 144 fish for 115 h of effort (1.25 fish per hour). A subset of the catch comprised nine eligible species under competition rules, of which 47 pelagic fish were weighed. The largest fish captured was a 34.4 kg Sailfish (Istiophorus platypterus). The most common species captured and weighed was Spanish Mackerel (Scomberomorus commerson). The total weight of eligible fish was 332 kg and the average weight of each fish was 7.1 kg. During the two-day event, spearfishers functioned as citizen scientists and counted 358 sharks (115 h effort), averaging 3.11 sharks per hour. Grey Reef Sharks (Carcharhinus amblyrhynchos) comprised 64% of sightings. Nine speared fish were fully depredated by sharks as spearfishers attempted to retrieve their catch, which equates to a depredation rate of 5.9%. The depredated fish included four pelagic fish and five reef fish. The shark species responsible were Grey Reef Shark (C. amblyrhynchos) (66%), Bull Shark (Carcharhinus leucas) (11%), Whitetip Reef Shark (Triaenodon obesus) (11%) and Great Hammerhead (Sphyrna mokarran) (11%). There were spatial differences in fish catch, shark sightings and rates of depredation. We developed a report card that compared average catch of fish, sightings of sharks per hour and depredation rate by survey area, which assists recreational fishers and marine park managers to assess spatio-temporal changes. The participating spearfishers can be regarded as experienced (average 18 days a year for average 13.4 years). Sixty percent of interviewees perceived that shark numbers have increased in the past 10 years, 33% indicated no change and 7% indicated shark numbers had decreased. Total fuel use of all vessels was 2819 L and was equivalent to 6.48 tons of greenhouse gas emissions for the competition. [ABSTRACT FROM AUTHOR]

Reducing nutrient runoff from sugarcane production into the Great Barrier Reef (GBR) has become a major policy focus for the Queensland and Australian Governments. This study explores consumer willingness to pay (WTP) to achieve higher environmental standards for sugar originating from the GBR catchments, through the use of a GBR‐safe ecolabel. A Best‐Worst Scaling (BWS) and a Contingent Valuation (CV) experiment are conducted on a random sample of 1,100 Australian residents. The BWS experiment reveals that personal health considerations are more important than sustainability and environmental factors, including impacts on the GBR. Results of the CV experiment show that respondents are more likely to pay a premium to support Reef‐friendly sugar if they are living in urban areas, plan to visit the GBR in the future, think that the GBR condition has declined, and are generally concerned about keeping a healthy diet. We estimate that the average WTP is $24.5/year/household, which only represents 0.34 per cent of the average weekly grocery bill of Australian households. This small contribution through increased sugar prices could conservatively raise $46.9M/year in support of sugar producers to improve water quality in the GBR. Based on these results, we recommend policy‐makers consider instruments that further involve sugar consumers. [ABSTRACT FROM AUTHOR]

Coral reefs have been found to produce the sulfur compound dimethyl sulfide (DMS), a climatically relevant aerosol precursor predominantly associated with phytoplankton. Until recently, the role of coral-reef-derived DMS within the climate system had not been quantified. A study preceding the present work found that DMS produced by corals had negligible long-term climatic forcing at the global–regional scale. However, at sub-daily timescales more typically associated with aerosol and cloud formation, the influence of coral-reef-derived DMS on local aerosol radiative effects remains unquantified. The Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) has been used in this work to study the role of coral-reef-derived DMS at sub-daily timescales for the first time. WRF-Chem was run to coincide with an October 2016 field campaign over the Great Barrier Reef, Queensland, Australia, against which the model was evaluated. After updating and scaling the DMS surface water climatology, the model reproduced DMS and sulfur concentrations well. The inclusion of coral-reef-derived DMS resulted in no significant change in sulfate aerosol mass or total aerosol number. Subsequently, no direct or indirect aerosol effects were detected. The results suggest that the co-location of the Great Barrier Reef with significant anthropogenic aerosol sources along the Queensland coast prevents coral-reef-derived aerosol from having a modulating influence on local aerosol burdens in the current climate. [ABSTRACT FROM AUTHOR]

To protect and improve water quality in the Great Barrier Reef, the Queensland Government's Reef 2050 Water Quality Improvement Plan targets that 90% of sugarcane, horticulture, cropping and grazing lands in priority areas be managed using best management practices for sediment, nutrient and pesticides by 2025. Progress towards this target is insufficient and variable across catchments and industries. The motivation to adopt improvements in management practices is heavily influenced by social, economic, cultural and institutional dimensions. In this paper we synthesise the literature on how these human dimensions influence decision making for land management practice and highlight where future investment could be focussed. We highlight that focussing on —1) investigating systems to support landholder decision making under climate uncertainty (risk); 2) generating a better understanding of the extent and drivers of landholder transaction cost; 3) understanding if there are competing 'right' ways to farm; and 4) improving understanding of the social processes, trust and power dynamics within GBR industries and what these means for practice change— could improve practice change uptake in the future. • Understanding human factors is essential for land practice change • Human factors include economic, social and cultural and macro institutional elements • These will affect trialling, adoption and dis-adoption of a practice [ABSTRACT FROM AUTHOR]

The Reef 2050 Plan has identified a range of measures aimed at reducing end-of-catchment loads of sediment and nutrient and recognizes the role that freshwater wetlands may have in achieving this. However, quantitative information on the potential for tropical wetlands to filter agricultural runoff is scarce, so this paper describes a study that combines field data from a 10 ha wetland constructed on land previously used for sugar cane near Babinda, north Queensland with a water balance and denitrification model. During the 12-month monitoring period (from October 2017 to September 2018) we estimate that the nitrogen filtering capacity of the wetland was 52% (26% lost as gaseous denitrification from the water and soil, and 26% as sedimentation of particulate nitrogen, PN). The remaining nitrogen (48%) left in the drainage water and this emphasises the importance of the wetland hydrology in determining denitrification and filtering. The current estimates are highly variable, so we have also identified the key parameters that need to be measured in order to improve long-term wetland filtering capacity estimation. Babinda is in the Mulgrave-Russell catchment, where the Reef 2050 Water Quality Improvement Plan has set target reductions in DIN of 300 t and PN of 53 t by 2025. 10% of the DIN reduction target could be achieved from ~593 ha of wetland with the same mean denitrification properties as currently estimated for the Babinda wetland (i.e. 51 kg N ha−1 year−1). This amounts to 2.3% of the total sugarcane area in this catchment that, as wetland, would also remove 56% of the 2025 PN reduction target. • Combined water balance and denitrification modelling of a tropical wetland • Estimation of total nitrogen filtering in a constructed wetland • Clear demonstration of the importance of hydrology in wetland filtering • Identification of key parameters affecting wetland filtering • Potential contribution of wetlands to Reef water quality improvement targets [ABSTRACT FROM AUTHOR]

Abstract: The focus of the research reported in this paper has been to estimate recreation values for beaches over approximately 1,400 km (km) of coastline along the Queensland coast. The study is notable at an international level because it assesses recreation values to a general type of recreation asset rather than to a specific site, and because it focuses on the values of the local resident population. Negative binomial models have been used to estimate both the visit rate and recreation values associated with beach visits in different regional areas. The value of a single beach visit was estimated per person at $35.09, which extrapolates to $587.3 million in beach recreation values per annum. These values are likely to be conservative because opportunity costs incurred to live closer to the beach (e.g. housing premiums) have not been assessed. Contingent behaviour models were used to estimate the values of potential declines in water quality, with marginal effects assessed at $1.30 per recreation trip to avoid each 1% decline in water quality. [Copyright &y& Elsevier]

Abstract: The use of landholder typologies to assist in the development of natural resource management (NRM) policies and agricultural extension programs has increased considerably in the past decade. In this paper we explore the potential of developing a typology of graziers to more effectively tailor policies and programs with the aim of improving land management outcomes. This is of particular importance since growing public concern about the environmental performance of the beef industry has led to increasing pressures on graziers to change their land management practices to decrease off-property impacts. To gain a better understanding of graziers’ land management practices and the factors that inform their decisions on how they manage their land we first developed a conceptual model of the relationship between grazier and grazing land where both can, ideally, thrive through conscious and timely land management decisions made and implemented by the grazier. A successful grazier land relationship is likely to be consistent with value systems and social and economic factors, although the particulars of any individual approach may vary spatially and temporally. These factors, in particular graziers’ values and motivations to follow a particular management strategy, guided the development of our typology of graziers. Australia''s Bowen-Broken basin, which has been identified as a major contributor of sediment and nutrients that enter the Great Barrier Reef lagoon, served as a case study for this research. Three broad types of graziers emerged: (1) traditionalists, (2) diversifiers, and (3) innovators. The authors argue that by understanding graziers’ values and motivations underlying each of the grazier types, government agencies and NRM organisations can more effectively tailor their policy and extension programs towards specific types of graziers and can work with specific groups to achieve reductions in sediment and nutrient runoff from grazing properties. [Copyright &y& Elsevier]

New regionalism encompasses a diversity of approaches to address regional planning problems. Within Australia, the Great Barrier Reef Water Quality Protection Plan was developed to enhance water quality within the World Heritage-listed Great Barrier Reef, and the plan gave responsibility to regional, natural resource management bodies to undertake several actions. This paper evaluates these initiatives in the light of the emerging theory of new regionalism and highlights six main lessons: up-scaling of the catchment approach to a reef-wide approach is essential in order to improve water quality, but must be complemented by cross-regional collaboration; new governance and institutional arrangements and strengthened partnerships must be effectively integrated; culture and history are important in determining the most effective management approaches; pilot projects must move to comprehensive and strategic implementation; science is important but needs to incorporate other branches of knowledge; and economic incentives are important in encouraging the implementation of best practices, but delivery needs to be flexible. We conclude that the new regional approach is appropriate for addressing complex, multi-scale problems such as water quality, and has incorporated several key principles of new regionalism, but that the process must move quickly to a higher level of commitment and application. [ABSTRACT FROM AUTHOR]

The tourism literature offers a number of different themes related to defining and understanding the long stay, independent travel of younger people often, referred to as backpacking. This paper focuses on the two major themes of differences between backpackers and other tourists, and change over time in backpacking, through an examination of survey data collected from tourists to Australia's Great Barrier Reef in 1996, 2001 (prior to the event of September 11) and in 2002 (prior to the Bali Bombing). Backpackers were compared to Other Younger Travellers at each of these three times on a number of variables including travel party, motivations, type of reef trip chosen, and satisfaction. The results supported three main conclusions. Firstly, Backpackers differed from Other Younger Travellers on a number of variables and they retain some of these differences over time. Secondly, both groups changed over time, reflecting impacts of changes in international travel and contexts. Finally, although significant differences continued to exist between the two groups in each time period, over time tourists in the Other Younger Travellers group became more like Backpackers. The study concludes that the concept of backpacking as a rite de passage is worthy of further consideration and research attention. [ABSTRACT FROM AUTHOR]

Abstract: The cause(s) of primary outbreaks of the coral-eating crown-of-thorns starfish (Acanthaster planci) are still subject to scientific controversy. The possibility of primary outbreaks being linked to terrestrial runoff has been postulated a number of times, suggesting that enhanced nutrient supply is critical for enhanced A. planci larval development. This paper examines the evidence for such a cause, focussing particularly on the Great Barrier Reef (GBR). Nutrient discharges from rivers have increased at least four-fold in the central GBR over the last century, and concentrations of large phyto-plankton (>2μm) of the inshore central GBR shelf in the wet season when A. planci larvae develop, is double that of other places and times. Larval development, growth and survival increase almost ten-fold with doubled concentrations of large phyto-plankton. This and other lines of evidence suggest that frequent A. planci outbreaks on the GBR may indeed be a result of increased nutrient delivery from the land. [Copyright &y& Elsevier]

Abstract: This paper presents a multi-criteria based tool for assessing the relative impact of diffuse-source pollution to the Great Barrier Reef (GBR) from the river basins draining into the GBR lagoon. The assessment integrates biophysical and ecological data of water quality and pollutant concentrations with socio-economic information pertaining to non-point source pollution and (potential) pollutant impact. The tool generates scores for each river basin against four criteria, thus profiling the basins and enabling prioritization of management alternatives between and within basins. The results support policy development for pollution control through community participation, scientific data integration and expert knowledge contributed by people from across the catchment. The results specifically provided support for the Reef Water Quality Protection Plan, released in October 2003. The aim of the plan is to provide a framework for reducing discharge of sediment, nutrient and other diffuse-source loads and (potential) impact of that discharge and for prioritising management actions both between and within river basins. [Copyright &y& Elsevier]

Abstract: Along the tropical coastline of the Great Barrier Reef (GBR) region, little is known to date about submarine groundwater discharge (SGD) into the near-shore ocean. In an oceanographic sense, SGD consists of freshwater flow from land as well as seawater circulated through sediments. Recent radiochemical and geophysical studies, using the tracer 222Rn and apparent ground conductivity respectively, provide evidence for SGD to occur in a variety of hydrogeological settings. In this paper, a non-quantitative overview of different settings of SGD in the region is presented: (1) recirculation of seawater through animal burrows in mangrove forests, (2) freshwater SGD from unconfined aquifers as a narrow coastal fringe of freshwater along Wet Tropics beaches, (3) SGD from coastal dune systems in form of localised freshwater springs in the intertidal zone, (4) inner-shelf SGD from confined submarine aquifer systems comprised of riverine paleochannels incised into the shelf. [Copyright &y& Elsevier]

Presents a paper on gonad development and evidence of protogyny in the red-throat emperor Lethrinus (L.) miniatus on the Great Barrier Reef, Queensland. Concurrent degeneration of all oocytes and proliferation of spermatocysts near lamellae in transitional L. miniatus; Implications of the presence of spermatocysts in the females; Unusual characteristics of transitional L. miniatus.

Summary: We consider estimating the total load from frequent flow data but less frequent concentration data. There are numerous load estimation methods available, some of which are captured in various online tools. However, most estimators are subject to large biases statistically, and their associated uncertainties are often not reported. This makes interpretation difficult and the estimation of trends or determination of optimal sampling regimes impossible to assess. In this paper, we first propose two indices for measuring the extent of sampling bias, and then provide steps for obtaining reliable load estimates that minimizes the biases and makes use of informative predictive variables. The key step to this approach is in the development of an appropriate predictive model for concentration. This is achieved using a generalized rating-curve approach with additional predictors that capture unique features in the flow data, such as the concept of the first flush, the location of the event on the hydrograph (e.g. rise or fall) and the discounted flow. The latter may be thought of as a measure of constituent exhaustion occurring during flood events. Forming this additional information can significantly improve the predictability of concentration, and ultimately the precision with which the pollutant load is estimated. We also provide a measure of the standard error of the load estimate which incorporates model, spatial and/or temporal errors. This method also has the capacity to incorporate measurement error incurred through the sampling of flow. We illustrate this approach for two rivers delivering to the Great Barrier Reef, Queensland, Australia. One is a data set from the Burdekin River, and consists of the total suspended sediment (TSS) and nitrogen oxide (NO x ) and gauged flow for 1997. The other dataset is from the Tully River, for the period of July 2000 to June 2008. For NO x Burdekin, the new estimates are very similar to the ratio estimates even when there is no relationship between the concentration and the flow. However, for the Tully dataset, by incorporating the additional predictive variables namely the discounted flow and flow phases (rising or recessing), we substantially improved the model fit, and thus the certainty with which the load is estimated. [Copyright &y& Elsevier]

Abstract: Skeletal density and porosity characteristics are key parameters for investigations into scleractinian coral growth and for assessing the effects of a range of anthropogenic influences on coral reefs. Typically, skeletal density is measured by using planar X-rays of thin slabs cut from mound-shaped colonies or, for branching forms, by using methods based on Archimedean principles. This paper describes a novel non-destructive technique based on micro-computed tomography (micro-CT) to measure porosity of branching coral skeleton. This approach incorporates methods for segmenting internal and external portions of branch and for distinguishing between skeleton and air, whilst accounting for the effects of beam hardening. Measurements were obtained from colonies of branching Acropora pulchra collected across a reef-flat transect at King Reef, central nearshore Great Barrier Reef. The results show significant variation in porosity within and among branches sampled from individual colonies, but not within a reef-flat transect. Micro-CT techniques yield comparable results to traditional methods based on Archimedean principles, but offer advantages in their suitability for a wider range of coral specimens because of the non-destructive nature of the technique and in their more rigorous control of model parameters that can bias results. [ABSTRACT FROM AUTHOR]

Summary: This paper presents a tool for documenting and monitoring water use benefits in the Great Barrier Reef catchments that allows temporal and spatial comparison along the region. Water, water use benefits and water allocations are currently receiving much attention from Australian policy makers and conservation practitioners. Because of the inherent complexity and variability in water quality, it is essential that scientific information is presented in a meaningful way to policy makers, managers and ultimately, to the general public who have to live with the consequences of the decisions. We developed an inexpensively populated and easily understandable water use benefit index as a tool for community-based monitoring of water related trends in the Great Barrier Reef region. The index is developed based on a comparative list of selected water-related indices integrating attributes across physico-chemical, economic, social, and ecological domains currently used in the assessment of water quality, water quantity and water use benefits in Australia. Our findings indicate that the proposed index allows the identification of water performance indicators by temporal and spatial comparisons. Benefits for decision makers and conservation practitioners include a flexible way of prioritization towards the domain with highest concern. The broader community benefits from a comprehensive and user-friendly tool, communicating changes in water quality trends more effectively. [ABSTRACT FROM AUTHOR]

Summary: In many agricultural regions investments are made into improved land management and catchment restoration with the aim of reducing sediment and nutrient delivery to downstream water bodies. This paper presents the results of an 8year field study that evaluated the impact of improved grazing land management (GLM) on a 14km2 sub-catchment of the Burdekin River in northern Australia. Land condition recovery and changes to runoff and sediment yield were measured on hillslopes (using three flumes) and at the end of the catchment (using automatic water sampling). Ground cover was monitored at the beginning of the wet season at hillslope and catchment scales using direct measurement and Quickbird satellite imagery. At the catchment scale, improved GLM resulted in an increase in mean ground cover between 2003 and 2007, relative to a control grazing property. However, the total suspended sediment yield from hillslopes did not decline due to the disproportionately high yields from low (<10%) cover sites particularly in high runoff years. In 2007, when there was above-average rainfall, 97% of the hillslope derived fine sediment was coming from less than 3% of the catchment. Catchment sediment yield also increased, associated with higher rainfall and runoff in latter years of the study. In years of above-average rainfall, it is estimated that less than 40% of catchment sediment yield was derived from hillslope erosion. Channel erosion is considered to contribute the remaining sediment. Rehabilitation of hillslope scalds and gullies is likely to be an important companion to improved GLM to reduce catchment fine sediment yields in this landscape. Evaluation of gully and hillslope scald rehabilitation techniques is required, including the economic feasibility of such options. [Copyright &y& Elsevier]

Summary: Poor land condition resulting from unsustainable grazing practices can reduce enterprise profitability and increase water, sediment and associated nutrient runoff from properties and catchments. This paper presents the results of a 6year field study that used a series of hillslope flume experiments to evaluate the impact of improved grazing land management (GLM) on hillslope runoff and sediment yields. The study was carried out on a commercial grazing property in a catchment draining to the Burdekin River in northern Australia. During this study average ground cover on hillslopes increased from ∼35% to ∼75%, although average biomass and litter levels are still relatively low for this landscape type (∼60 increasing to 1100kg of dry matter per hectare). Pasture recovery was greatest on the upper and middle parts of hillslopes. Areas that did not respond to the improved grazing management had <10% cover and were on the lower slopes associated with the location of sodic soil and the initiation of gullies. Comparison of ground cover changes and soil conditions with adjacent properties suggest that grazing management, and not just improved rainfall conditions, were responsible for the improvements in ground cover in this study. The ground cover improvements resulted in progressively lower runoff coefficients for the first event in each wet season, however, runoff coefficients were not reduced at the annual time scale. The hillslope annual sediment yields declined by ∼70% on two out of three hillslopes, although where bare patches (with <10% cover) were connected to gullies and streams, annual sediment yields increased in response to higher rainfall in latter years of the study. It appears that bare patches are the primary source areas for both runoff and erosion on these hillslopes. Achieving further reductions in runoff and erosion in these landscapes may require management practices that improve ground cover and biomass in bare areas, particularly when they are located adjacent to concentrated drainage lines. [Copyright &y& Elsevier]

Abstract: Tropical cyclones affect storm-dominated sediment transport processes that characterise Holocene shelf deposits in many shelf environments. A summary of cyclone-associated deposits in the Great Barrier Reef published by Larcombe and Carter [2004. Cyclone pumping, sediment partitioning and the development of the Great Barrier Reef shelf system: a review. Quaternary Science Reviews 23, pp. 107–135 indicates a pervasive northwards orientation of deposits on the lee side of reefs and other obstacles. In this paper, we describe the geomorphology of reef talus deposits found in the Gulf of Carpentaria and Arafura Sea, Australia, that we attribute to tropical cyclones. The orientation of these deposits is also indicative of a consistent, along-coast transport pathway. The deposits are located on the leeward side of submerged coral reefs; they are up to 10m in thickness, comprised of re-worked carbonate sand and gravel and radiocarbon dating indicates that they are of Holocene age. An explanation for the consistent along-coast cyclone transport pathway is presented based on previously published hydrodynamic modelling results. These models illustrate how currents generated by the passage of a cyclone are asymmetric in plan view, such that stronger flows are generated between the eye of the cyclone and the coast. The result of the passage of many cyclones over geologic timescales is a net along-coast sediment transport pathway located on the inner- to mid-shelf, possibly extending over the entire length of northern Australia''s coastline. This process provides an explanation for the observed sediment transport patterns on modern tropical continental shelves, as well as a basis for the interpretation of ancient tropical shelf deposits. [Copyright &y& Elsevier]

Abstract: Dr Jack Handyside Barnes (1922–1985) was one of the small and elite group of Pacific marine toxinologists whose work was characterised by an uncompromising rugged persona, a focussed resolve to solve challenging problems of human clinical envenomation, and who conducted curiosity-driven research under conditions of scientific isolation. He was a pioneering advocate for the preservation of marine heritage, particularly that of the Great Barrier Reef. A former military commando who later became a general medical practitioner with extensive surgical and obstetric skills, in 1947 he was appointed the Medical Superintendent of Thursday Island in the Torres Strait. Later (from January 1953), he worked indefatigably as a general medical practitioner in Cairns, in tropical North Australia. For four decades (1945–1985), Jack Barnes undertook detailed laboratory, clinical and field research into invertebrate envenomation, particularly medusan toxinology. In 1960 he discovered the species responsible for the Irukandji syndrome, a small carybdeid named Carukia barnesi in his honour. He invented the research technique for the extraction of venom from the world''s most venomous creature, the Pacific box Jellyfish, Chironex fleckeri. By 1960, he had published taxonomic details of nematocyst structure and clinical envenomation details consequent upon stings by Physalia, Cyanea, Chironex, Chiropsalmus and Carukia. This paper is a précis of the chronology of his life, contributions and influence. [Copyright &y& Elsevier]

The Great Barrier Reef World Heritage Area in Queensland, Australia contains globally significant seagrasses supporting key ecosystem services, including habitat and food for threatened populations of dugong and turtle. We compiled 35 years of data in a spatial database, including 81,387 data points with georeferenced seagrass and species presence/absence, depth, dominant sediment type, and collection date. We include data collected under commercial contract that have not been publicly available. Twelve seagrass species were recorded. The deepest seagrass was found at 76 m. Seagrass meadows are at risk from anthropogenic, climate and weather processes. Our database is a valuable resource that provides coastal managers and the global marine community with a long‐term spatial resource describing seagrass populations from the mid‐1980s against which to benchmark change. We address the data issues involved in hindcasting over 30 years to ensure confidence in the accuracy and reliability of data included. [ABSTRACT FROM AUTHOR]

Few studies have considered linkages of mobile predators across large spatial scales despite their significant and often critical role in maintaining ecosystem function and health. The bull shark (Carcharhinus leucas) is a large, widespread coastal predator capable of undertaking long-range movement, but there is still limited understanding of intra-regional differences in movement and habitat connectivity across latitudes within the same coastline. This study used acoustic telemetry data and network analyses to investigate long-range movements, residency patterns and seasonal habitat linkages of sub-adult and adult C. leucas along the east coast of Australia. Our results revealed that C. leucas tagged in Sydney Harbour were mainly present within this temperate estuary in summer and autumn; the rest of the year individuals were detected in tropical and subtropical habitats from southern and central Queensland. In contrast, the detection probability of C. leucas tagged in the Townsville Reefs (central Great Barrier Reef) peaked in spring, with a portion of the tagged population migrating south during the summer months. Differences in residency time between tagging locations were also detected, as all C. leucas tagged in Sydney Harbour were absent between June and November, but 35% of the tropical-reef tagged population remained resident year-round. Network analyses complemented these findings by revealing different seasonal habitat use between regions, thus highlighting complex seasonal-habitat linkages of C. leucas along the coast. Our findings support the hypothesis that the timing, duration, and drivers involved in the long-range movements and connectivity of sub-adult and adult C. leucas vary between latitudinal regions, most likely driven by the interaction between seasonal temperature changes, foraging and reproduction. [ABSTRACT FROM AUTHOR]

Australian and Queensland Government's Reef 2050 Water Quality Improvement Plan has set targets for improving the water quality entering the Great Barrier Reef lagoon. Given the large public investment and the deficit of data linking on-farm land management to changes in environmental outcomes, there is a need for a robust and efficient methods of quantifying links between land management and water quality. This paper explores a pragmatic approach to making this link using available data. We demonstrate that a simple parameterisation process is suitable for estimating hydrology and water quality across a wide range of land uses and management practices in agricultural landscapes. However, a manually calibrated model may still require the analysis of parameters to reduce error variances and evaluate uncertainties. Confidence in estimating hydrology and water quality in descending order is: runoff, sediment, nitrogen, phosphorous, and pesticide losses, reflecting the availability of data and inherent error propagation. • A pragmatic modelling by Howleaky is suitable to link management to water quality. • A manually calibrated model may still require a reduction in error variances. • Data availability and inherent error propagation determined confidence in modelling. [ABSTRACT FROM AUTHOR]

This article describes 3D medium (4km) and high (500m) horizontal resolution ocean models developed for the Coral Sea with a particular focus on the Great Barrier Reef lagoon. The medium resolution model is underpinning a 10 year reanalysis and a forecast demonstrator system for maritime monitoring. The ocean models have been developed to assist the management of the Great Barrier Reef given the existence of a number of stressors acting on the reef. The presented models aim to represent physical stressors that include thermal, salinity and flooding rivers. The river discharge is tracked by passive and age tracers. They can provide concentrations to identify the area/volume influenced by flood water. This paper gives an overview of the forward non-linear models with the aim to assess their performance. The models have been evaluated over a two year period spanning January 2009–March 2011 including the 2010/2011 La Nina and the advent of Tropical Cyclone Yasi in early 2011 that contributed to one of the largest river discharge events recorded over northern Queensland. The models' performance is investigated on a full domain scale via means of satellite sea surface temperature (SST), expendable bathythermograph (XBT) and drifter data. Over the shelf and the Great Barrier Reef lagoon, available tide gauges, Ocean Colour, Chlorophyll-a and Queensland's Integrated Marine Observing System (QIMOS) mooring data of temperature, salinity and velocity have been used to assess the models. Results suggest that the high resolution model gives better statistics in terms of mean absolute deviation and bias compared to the medium resolution model for subsurface temperature and salinity over the deep ocean. Moreover, sea surface temperature performance is similar for both models. Over the lagoon and shelf both models' performance is mixed. The high resolution model displays a consistent warm bias on the order of 0.3 °C over the shallow well mixed stations throughout the year. However, the 4km model displays larger variability in this region. It tends to be too warm in summer and too cool in winter when compared to moorings. Modelled velocities are assessed via means of the QIMOS moorings. Overall the high resolution model fares better in terms of current direction with an average veering of 13° vs. 22°. The models' performance is comparable in terms of current speed over the shallow moorings. However, the high resolution model is better equipped to represent steeper shelves and this results at times in better performance for velocity and temperature, particularly over Palm Passage. A large focus has been placed on including and assessing passive tracer dynamics emanating from river discharge. 25 river sources have been added across the models domain together with a set of one-dimensional channels representing the volume flux of brine. Two case studies are presented to demonstrate the models' ability to reproduce mean features of observed plumes. A major river discharge event has been examined in further detail. Both models are able to reproduce the low salinity signal present in the observations in the upper level to a satisfactory degree. The 4km model matches the observed strength and duration of the fresh water plume substantially better than the high resolution model in this case. • High and medium resolution ocean models for the Great Barrier Reef are presented. • Modelled passive and age tracers are compared to observed river plumes. • Intrusive upwelling onto the Great Barrier Reef may be affected by model resolution. • Horizontal model resolution affects performance over the Coral Sea. [ABSTRACT FROM AUTHOR]

The shallow tidal and freshwater coastal wetlands adjacent to the Great Barrier Reef lagoon provide a vital nursery and feeding complex that supports the life cycles of marine and freshwater fish, important native vegetation and vital bird habitat. Urban and agricultural development threaten these wetlands, with many of the coastal wetlands becoming lost or changed due to the construction of artificial barriers (e.g. bunds, roads, culverts and floodgates). Infestation by weeds has become a major issue within many of the wetlands modified (bunded) for ponded pasture growth last century. A range of expensive chemical and mechanical control methods have been used in an attempt to restore some of these coastal wetlands, with limited success. This study describes an alternative approach to those methods, investigating the impact of tidal reinstatement after bund removal on weed infestation, associated changes in water quality, and fish biodiversity, in the Boolgooroo lagoon region of the Mungalla wetlands, East of Ingham in North Queensland. High resolution remote sensing, electrofishing and in-water logging was used to track changes over time– 1 year before and 4 years after removal of an earth bund. With tides only penetrating the wetland a few times yearly, gross changes towards a more natural system occurred within a relatively short timeframe, leading to a major reduction in infestation of olive hymenachne, water hyacinth and salvina, reappearance of native vegetation, improvements in water quality, and a tripling of fish diversity. Weed abundance and water quality does appear to oscillate however, dependent on summer rainfall, as changes in hydraulic pressure stops or allows tidal ingress (fresh/saline cycling). With an estimated 30% of coastal wetlands bunded in the Great Barrier Reef region, a passive remediation method such as reintroduction of tidal flow by removal of an earth bund or levee could provide a more cost effective and sustainable means of controlling freshwater weeds and improving coastal water quality into the future. [ABSTRACT FROM AUTHOR]