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A mortality event involving 23 allied rock‐wallabies (Petrogale assimilis) displaying neurological signs and sudden death occurred in late April to May 2021 in a suburban residential area directly adjacent to Magnetic Island National Park, on Magnetic Island (Yunbenun), North Queensland, Australia. Three allied rock‐wallabies were submitted for necropsy, and in all three cases, the cause of death was disseminated toxoplasmosis. This mortality event was unusual because only a small, localised population of native wallabies inhabiting a periurban area on a tropical island in the Great Barrier Reef World Heritage Area were affected. A disease investigation determined the outbreak was likely linked to the presence of free‐ranging feral and domesticated cats inhabiting the area. There were no significant deaths of other wallabies or wildlife in the same or other parts of Magnetic Island (Yunbenun) at the time of the outbreak. This is the first reported case of toxoplasmosis in allied rock‐wallabies (Petrogale assimilis), and this investigation highlights the importance of protecting native wildlife species from an infectious and potentially fatal parasitic disease. [ABSTRACT FROM AUTHOR]

Australia’s coastal marine ecosystems have a deep cultural significance to Indigenous Australians, include multiple World Heritage sites, and support the nation’s rapidly growing blue economy. Yet, increasing local pressures and global climate change are expected to undermine the biological, social, cultural, and economic value of these ecosystems within a human generation. Mitigating the causes of climate change is the most urgent action to secure their future; however, conventional and new management actions will play roles in preserving ecosystem function and value until that is achieved. This includes strategies codeveloped with Indigenous Australians that are guided by traditional ecological knowledge and a modeling and decision support framework. We provide examples of developments at one of Australia’s most iconic ecosystems, the Great Barrier Reef, where recent, large block funding supports research, governance, and engagement to accelerate the development of tools for management under climate change. [ABSTRACT FROM AUTHOR]

Report cards that are designed to monitor environmental trends have the potential to provide a powerful communication tool because they are easy to understand and accessible to the general public, scientists, managers and policy makers. Given this functionality, they are increasingly popular in marine ecosystem reporting. We describe a report card method for seagrass that incorporates spatial and temporal variability in three metrics—meadow area, species and biomass—developed using long-term (greater than 10 years) monitoring data. This framework summarises large amounts of spatially and temporally complex data to give a numeric score that provides reliable comparisons of seagrass condition in both persistent and naturally variable meadows. We provide an example of how this is applied to seagrass meadows in an industrial port in the Great Barrier Reef World Heritage Area of north-eastern Australia. [ABSTRACT FROM AUTHOR]

This timely collation of case studies, written by and with Traditional Owners of diverse Australian offshore islands, offers direct insights into benefits arising from strategic and participatory action planning for biocultural island conservation and monitoring. We pay respect to the Old People and Elders whose dedicated care of their island homelands means we today can still experience their cultural and natural diversity. We extend greetings to our Pacifika neighbours, and to carers of islands around Earth. Our paper scopes socio-economic benefits arising from planning for islands, for Aboriginal peoples and Torres Strait Islanders, and more generally. Global, national, state and local co-investments support place-specific planning for some islands by Traditional Owners as a starting point toward shared governance and caring for Country. Case studies describe Country planning for Mayala Country in Australia's northwest, Woppaburra experiences within the Great Barrier Reef World Heritage Area and integrated biocultural health monitoring arising from remote island Indigenous Protected Area planning in Torres Strait. New institutional initiatives are also seeking to create solid foundations for more substantive island research collaborations. Across Australia, novel relationships grounded in culturally assured, holistically integrated approaches to island governance and caring for Country involving Traditional Owners and island resource users/managers are creating equity in livelihoods and stronger wellbeing. Australia's innovative Sea Country collaborations, with priorities initiated and led by island Traditional Owners, carry real value for sustained island conservation and provide positive inspirations for global humanity in the accelerating Anthropocene. Earth's islands face grave challenges. In Australia, innovation in island knowledge sharing between Traditional Owners and other island users and managers is moving beyond the participatory action planning space to generate equity in livelihoods and wellbeing on Sea Country. The tangible benefits arising are grounded in cultural governance and authority. [ABSTRACT FROM AUTHOR]

Seagrass meadows are a key ecosystem of the Great Barrier Reef World Heritage Area, providing one of the natural heritage attributes underpinning the reef's outstanding universal value. We reviewed approaches employed to date to create maps of seagrass meadows in the optically complex waters of the Great Barrier Reef and explored enhanced mapping approaches with a focus on emerging technologies, and key considerations for future mapping. Our review showed that field-based mapping of seagrass has traditionally been the most common approach in the GBRWHA, with few attempts to adopt remote sensing approaches and emerging technologies. Using a series of case studies to harness the power of machine- and deep-learning, we mapped seagrass cover with PlanetScope and UAV-captured imagery in a variety of settings. Using a machine-learning pixel-based classification coupled with a bootstrapping process, we were able to significantly improve maps of seagrass, particularly in low cover, fragmented and complex habitats. We also used deep-learning models to derive enhanced maps from UAV imagery. Combined, these lessons and emerging technologies show that more accurate and efficient seagrass mapping approaches are possible, producing maps of higher confidence for users and enabling the upscaling of seagrass mapping into the future. [ABSTRACT FROM AUTHOR]

The Great Barrier Reef World Heritage Area (GBRWHA) in north eastern Australia spans 2500 km of coastline and covers an area of ~ 350,000 km2. It includes one of the world's largest seagrass resources. To provide a foundation to monitor, establish trends and manage the protection of seagrass meadows in the GBRWHA we quantified potential seagrass community extent using six random forest models that include environmental data and seagrass sampling history. We identified 88,331 km2 of potential seagrass habitat in intertidal and subtidal areas: 1111 km2 in estuaries, 16,276 km2 in coastal areas, and 70,934 km2 in reef areas. Thirty-six seagrass community types were defined by species assemblages within these habitat types using multivariate regression tree models. We show that the structure, location and distribution of the seagrass communities is the result of complex environmental interactions. These environmental conditions include depth, tidal exposure, latitude, current speed, benthic light, proportion of mud in the sediment, water type, water temperature, salinity, and wind speed. Our analysis will underpin spatial planning, can be used in the design of monitoring programs to represent the diversity of seagrass communities and will facilitate our understanding of environmental risk to these habitats. [ABSTRACT FROM AUTHOR]

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]

The Great Barrier Reef is an iconic ecosystem, known globally for its rich marine biodiversity that includes many thousands of tropical breeding seabirds. Despite indications of localized declines in some seabird species from as early as the mid‐1990s, trends in seabird populations across the reef have never been quantified. With a long history of human impact and ongoing environmental change, seabirds are likely sentinels in this important ecosystem. Using 4 decades of monitoring data, we estimated site‐specific trends for 9 seabird species from 32 islands and cays across the reef. Trends varied markedly among species and sites, but probable declines occurred at 45% of the 86 species‐by‐site combinations analyzed compared with increases at 14%. For 5 species, we combined site‐specific trends into a multisite trend in scaled abundance, which revealed probable declines of Common Noddy (Anous stolidus), Sooty Tern (Onychoprion fuscatus), and Masked Booby (Sula dactylatra), but no long‐term changes in the 2 most widely distributed species, Greater Crested Tern (Thalasseus bergii) and Brown Booby (Sula leucogaster). For Brown Booby, long‐term stability largely resulted from increases at a single large colony on East Fairfax Island that offset declines at most other sites. Although growth of the Brown Booby population on East Fairfax points to the likely success of habitat restoration on the island, it also highlights a general vulnerability wherein large numbers of some species are concentrated at a small number of key sites. Identifying drivers of variation in population change across species and sites while ensuring long‐term protection of key sites will be essential to securing the future of seabirds on the reef. Article Impact Statement: Four decades of monitoring reveals troubling trends for seabird breeding populations across the Great Barrier Reef. [ABSTRACT FROM AUTHOR]

Over the past 50 years, the diversity of fisheries types being actively managed has changed from mainly data-rich, industrial sectors to more socially, economically, and environmentally complex multispecies and multisector fisheries. Accompanying this change has been a broadening of management objectives to include social and economic considerations with traditional resource sustainability objectives, the so-called triple bottom line, and the need to include these considerations into harvest strategies. The case of a line fishery in Australia's Great Barrier Reef is used as a demonstration of the first steps in implementing triple bottom line harvest strategies. This fishery has several disparate sectors including commercial, tourism, and recreation; targets multiple but important reef species; and is undertaken in a World Heritage Site. This work highlights the need for a much-expanded set of objectives elicited from stakeholders that are either included in the trade-off analyses of the different harvest strategies or directly in an optimization. Both options demonstrated that a paradigm shift is required to emphasize representative participatory management systems that assemble teams from quite different backgrounds and viewpoints; use much broader set of objectives; and modify tools and (especially) the data collected within revised monitoring programmes to underpin these tools. [ABSTRACT FROM AUTHOR]

Agriculture within the Great Barrier Reef catchment area has contributed to pesticide contamination of adjacent freshwater ecosystems that flow into the Great Barrier Reef World Heritage Area. A novel multispecies toxicity test was used to assess the toxicity of diuron and hexazinone, 2 herbicides commonly detected within the Great Barrier Reef catchment area, to a community of 3 tropical freshwater microalgae: Monoraphidium arcuatum, Nannochloropsis‐like sp., and Pediastrum duplex. Diuron was the most toxic herbicide, with 10% inhibition concentration (IC10) values of 4.3, 7.1, and 29 µg/L for P. duplex, M. arcuatum, and Nannochloropsis‐like sp., respectively, followed by hexazinone, with IC10 values of 15, 18, and 450 µg/L, respectively Toxicity testing on 2 commercial formulations (Barrage, 13.2% hexazinone and 48.6% diuron; Diurex, 90% diuron) showed that additives in the commercial formulations did not significantly increase the toxicity of diuron. Direct toxicity assessments were carried out on water samples from the herbicide‐contaminated Sandy Creek, which discharges to the Great Barrier Reef lagoon, and a clean reference site, Tully Gorge in the Tully River. Toxicity was observed in several Sandy Creek samples. Artificial herbicide mixtures were assessed in synthetic soft water and natural freshwaters, with toxic responses being observed at environmentally relevant concentrations. The present study successfully applied a novel multispecies tropical microalgal toxicity test, indicating that it is an effective tool for the assessment of herbicide toxicity in both natural and synthetic freshwaters. Environ Toxicol Chem 2021;40:473–486. © 2020 SETAC [ABSTRACT FROM AUTHOR]

Long distance dispersal (LDD) contributes to the replenishment and recovery of tropical seagrass habitats exposed to disturbance, such as cyclones and infrastructure development. However, our current knowledge regarding the physical attributes of seagrass fragments that influence LDD predominantly stems from temperate species and regions. The goal of this paper is to measure seagrass fragment density and viability in two tropical species, assessing various factors influencing their distribution. We measured the density and viability of floating seagrass fragments for two tropical seagrass species (Zostera muelleri and Halodule uninervis) in two coastal seagrass meadows in the central Great Barrier Reef World Heritage Area, Australia. We assessed the effect of wind speed, wind direction, seagrass growing/senescent season, seagrass meadow density, meadow location and dugong foraging intensity on fragment density. We also measured seagrass fragment structure and fragment viability; i.e., potential to establish into a new plant. We found that seagrass meadow density, season, wind direction and wind speed influenced total fragment density, while season and wind speed influenced the density of viable fragments. Dugong foraging intensity did not influence fragment density. Our results indicate that wave action from winds combined with high seagrass meadow density increases seagrass fragment creation, and that more fragments are produced during the growing than the senescent season. Seagrass fragments classified as viable for Z. muelleri and H. uninervis had significantly more shoots and leaves than non-viable fragments. We collected 0.63 (±0.08 SE) floating viable fragments 100 m−2 in the growing season, and 0.13 (±0.03 SE) viable fragments 100 m−2 in the senescent season. Over a third (38%) of all fragments collected were viable. There is likely to be a large number of viable seagrass fragments available for long distance dispersal. This study's outputs can inform dispersal and connectivity models that are used to direct seagrass ecosystem management and conservation strategies. • There are large numbers of viable seagrass fragments available for dispersal. • Moderate winds with high seagrass density increases seagrass fragment creation. • More seagrass fragments are produced during the growing than the senescent season. • Seagrass fragments have more shoots and leaves than non-viable fragments. • Over a third (38%) of all floating fragments are viable. [ABSTRACT FROM AUTHOR]

Seawater acidification from increasing CO2 is often enhanced in coastal waters due to elevated nutrients and sedimentation. Our understanding of the effects of ocean and coastal acidification on present‐day ecosystems is limited. Here we use data from three independent large‐scale reef monitoring programs to assess coral reef responses associated with changes in mean aragonite saturation state (Ωar) in the Great Barrier Reef World Heritage Area (GBR). Spatial declines in mean Ωar are associated with monotonic declines in crustose coralline algae (up to 3.1‐fold) and coral juvenile densities (1.3‐fold), while non‐calcifying macroalgae greatly increase (up to 3.2‐fold), additionally to their natural changes across and along the GBR. These three key groups of organisms are important proxies for coral reef health. Our data suggest a tipping point at Ωar 3.5–3.6 for these coral reef health indicators. Suspended sediments acted as an additive stressor. The latter suggests that effective water quality management to reduce suspended sediments might locally and temporarily reduce the pressure from ocean acidification on these organisms. [ABSTRACT FROM AUTHOR]

Natural ecosystems hold great place within the hearts and lives of people, particularly those within which people live and work. However, whether people equally value natural ecosystems that they regularly frequent is effectively unknown. Such knowledge would greatly assist natural resource managers to better understand what they are protecting, why and for whom. In this paper we look at the different values that people hold for different ecosystems within the Great Barrier Reef (GBR). We test the relationship between eight different cultural values (using ecosystem services framing), and the use of seven different ecosystems (beaches, creeks and estuaries, islands and cays, inshore reefs, mid-shelf and outer reefs, open water, and shipwrecks) from face-to-face surveys of 1934 residents living within the GBR. We also look at whether the relationships that people have with each ecosystem inspires them to; (i) do more to help protect the GBR, (ii) learn more about the GBR, and (iii) feel personally affected if the health of the GBR declines. Results suggest that there are common reasons why all ecosystems are valued. All seven ecosystems were valued because they provide identity, quality of life and well-being, and inspired people to do more to help protect the GBR. Many were valued for their desirable and active way of life, learning about the environment through scientific discoveries, and learning about the condition of the GBR. However, some ecosystems were valued for special reasons. People that used beaches tended to have more pride in the World Heritage Area status of the GBR and appreciated the aesthetics of the GBR. People that used the mid-shelf and open-water areas were more likely to value biodiversity and aesthetics qualities. People that used inshore reefs were more likely to value economic benefits from the GBR. All residents said that they would be personally affected if the health of the GBR declined, except for those that used beaches, creeks and estuaries. Levels of concern for each of the ecosystems within the GBR varied, where people were more concerned about inshore areas than they were about coral reef condition. Specifically, people were most concerned about the level of rubbish on the beaches in their region and least about mangroves. These results suggest that, even though the GBR is valued in its entirety for many reasons, the GBR is not perceived as an entire ecosystem, but that people have different relationships within it. We discuss how environmental sustainability might be optimised through understanding and incentivising the multi-functionality of landscapes. • The GBR contains many sub-ecosystems, which are valued by people to different extents. • People value all sub-ecosystems for identity, lifestyle and well-being, and for specific reasons. • People are more concerned about rubbish on beaches than coral reef condition. • All sub-ecosystems can inspire people to better protect them. • These results can help managers understand what they are protecting, why and for whom. [ABSTRACT FROM AUTHOR]

Highlights • Ecosystem health report card for the largest port in the Great Barrier Reef. • Social, cultural, economic and environmental indicators of harbour health. • Innovative reporting infrastructure to ensure transparency and timely results. • Stakeholder-led vision underpinned by rigorous science and strong communication. Abstract Ecosystem health report cards are an increasingly popular means of summarizing the results of environmental monitoring programs for broad, non-scientific audiences. This paper describes a whole-of-system report card initiative developed to monitor the condition of a multi-use port in the Great Barrier Reef World Heritage Area, Queensland, Australia. Concerns over the impacts of major industrial expansion, fish health incidents, safety of recreational harbour users and habitat loss prompted stakeholders in the Gladstone region to unite and establish the Gladstone Healthy Harbour Partnership. The objective was to monitor and report on the health of the harbour via an annual report card (http://rc.ghhp.org.au/). We illustrate one approach to designing a report card against ten core considerations; 1) strong links to all stakeholders at all stages, 2) rigorous science, 3) effective communication, 4) setting clear goals and 5) realistic expectations, 6) flexibility in implementation, 7) transparency, open access and accountability, 8) results linked to actionable management recommendations, 9) regular evaluation, and 10) long term commitment. Innovative aspects of this report card include the combination of four components of harbour health: environmental, social, cultural and economic; underpinned by a sophisticated monitoring, modelling and reporting program. A review of the report card content and methodology, conducted in 2017, determined that the design meets the original vision and objectives set by Gladstone stakeholders. However, stakeholder perceptions of the effectiveness of the report card have not been comprehensively assessed to date. This paper provides a guide to others designing report card programs and environmental metrics, with advice on maximizing transparency and data sharing, coordinating otherwise disparate monitoring efforts, and linking with management through the provision of scenario analysis tools with which to interpret and respond to annual report card results. [ABSTRACT FROM AUTHOR]

Intraspecific variation in phenotypic traits of seagrasses enables populations to tolerate varying environmental conditions and facilitates population persistence and expansion. Significant variation in seagrass population morphometrics may reflect highly plastic responses to abiotic and biotic factors, allowing populations to acclimate to changing environmental conditions. Alternatively, morphological variation may arise from developmental canalisation or genetically determined fixed traits, which may inhibit future plasticity and adaptive flexibility to changing environmental conditions. Understanding the drivers behind intraspecific variation in phenotypic traits is important for seagrass restoration practitioners when identifying populations that may provide suitable donor propagules with high adaptability to new sites or propagules that may be more resilient to future environmental changes. This study aimed to investigate whether variation in morphological traits of four subpopulations of Zostera muelleri on the Curtis Coast of the Great Barrier Reef World Heritage Area, Queensland, correlated with meadow-specific environmental conditions and whether this varied between seasons. Morphometric analysis was conducted on Z. muelleri apical shoots, sampled during the spring growing/flowering season and autumn senescent season. Meadow-specific environmental conditions were assessed using historical data dating back to 2008 and environmental simulation models developed for predicting wave, and light conditions. Results indicated that Z. muelleri subpopulations exhibited distinct morphologies throughout their seasonal growth cycle that may correlate with meadow-specific differences in sediment composition, hydrodynamic stress, and light availability. However, further investigation is required to understand if expressed morphological traits are reflective of environmentally driven phenotypic plasticity or genetically predetermined fixed traits (local adaptation or developmental canalisation). Knowledge gained from further studies into the drivers behind the observed variations in morphological traits would increase the understanding of the importance of trait-based selection of propagules for seagrass restoration meadows' resilience and persistence. • Morphometrics and meadow-specific environmental conditions of Zostera muelleri subpopulations were analysed.. • Distinct morphological variations amongst subpopulations were detected throughout the seasonal growth cycle. • Morphological variations may correlate with differences in sediment composition, hydrology, and light availability. • Seagrass propagule trait-based selection may ultimately increase the success rate of seagrass restoration projects. [ABSTRACT FROM AUTHOR]

The Great Barrier Reef is the most recognizable of the Australian properties on United Nations Educational, Scientific and Cultural Organization’s (UNESCO) World Heritage List. At the time of its inscription in 1981, the International Union for the Conservation of Nature noted that ‘… if only one coral reef site in the world were to be chosen for the World Heritage List, the Great Barrier Reef is the site to be chosen’. The listing followed the ‘Save the Reef’ campaign, which ran through the 1960s and 1970s and highlighted threats from rapid industrialization and a nation riding a resources boom. Nevertheless, in recent years, the Reef has teetered on being named a ‘World Heritage Site in Danger’, with similar economic conditions driving its deterioration. This article juxtaposes recent media activism to protect the Reef against the earlier campaign in order to compare and better understand how these campaigns engaged publics and policy makers by representing and communicating threats, and concludes by considering their capacity to influence long-term conservation policy. [ABSTRACT FROM AUTHOR]

Seagrass habitats provide critical ecosystem services, yet there is ongoing concern over mounting pressures and continuing degradation. Defining a desired state for these habitats is a key step in implementing appropriate management but is often difficult given the challenges of available data and an evaluation of where to set benchmarks. We use more than 20 years of historical seagrass biomass data (1995–2018) for the diverse seagrass communities of Australia's Great Barrier Reef World Heritage Area (GBRWHA) to develop desired state benchmarks. Desired state for seagrass biomass was estimated for 25 of 36 previously defined seagrass communities with the remainder having insufficient data. Desired state varied by more than one order of magnitude between community types and was influenced by the mix of species in the communities and the range of environmental conditions. We identify a historical, decadal-scale cycle of decline with recovery to desired state in coastal intertidal communities. In contrast a number of the estuary and coastal subtidal communities have not recovered to desired state biomass. Understanding a historical context is critically important for setting benchmarks and making informed management decisions on the present state of seagrass in the GBRWHA. The approach we have developed is scalable for monitoring, management and assessment of pressures for other management areas and for other jurisdictions. Our results guide conservation planning through prioritization of the at-risk seagrass communities that are continuing to fall below their desired state. • Changes in biomass of seagrass communities were examined. • We estimate a desired state of biomass for each seagrass community. • We identify decadal-scale trends of loss and recovery for some communities. • In recent years desired state has not been attained for many communities. • Our approach enables the prioritization of management activities. [ABSTRACT FROM AUTHOR]

The Great Barrier Reef World Heritage Area, Australia, covers over 348,000 km2 of tropical marine ecosystems of global significance. In July 2015, the World Heritage Committee called attention to the cumulative impacts of climate change, poor water quality, and coastal development on the region's outstanding universal value, but stopped short of inscribing the Great Barrier Reef on the List of World Heritage in Danger. Restoring the region's values is hindered by an environmental decision-making process that fails to incorporate cumulative impacts, including the climate change impacts of greenhouse gas emissions sourced from one of Australia's largest exports, thermal coal. We identify policy and processes that enable a more comprehensive consideration of the cumulative effects of coal mining by environmental decision-makers. Implementing cumulative impact assessment requires a collaborative and transparent program of planning and monitoring independent of Government and mine proponents that evaluates local, regional, and global impacts. The future of the Great Barrier Reef depends on transformational change in the cumulative assessment of Australian coal mines. [ABSTRACT FROM AUTHOR]

Sustainable destinations must deliver products that perform better than their competitors and at the same time protect key environmental drawcards. This research explores the environmental–economic interface of a major destination, both as a case study in how to approach this complex relationship and as a contribution to the methodology of tackling the need for understanding competitive pressures as part of sustainable tourism strategy creation. Using the Great Barrier Reef World Heritage Area (GBRWHA) as an example, the paper assesses 21 key environmental values, including Indigenous culture, against market-based factors, in terms of their importance for visitors as regional drawcards, satisfaction with them and the way in which changes in them might affect trip numbers and duration across different regions. While the natural values of the GBRWHA are found to be the most important drawcards, satisfaction scores were significantly lower than importance scores for a number of these values. Visitors responded more negatively to the prospect of environmental degradation than to the prospect of a 20% increase in local prices: the detailed impact depends, however, on location and visitor mix. Clear ocean, healthy coral reefs, healthy reef fish, and lack of rubbish were the top four most important values. [ABSTRACT FROM PUBLISHER]

Tropical sea cucumbers are in peril due to overharvest. Sixteen species are endangered or vulnerable (IUCN) with high-value teatfish recently listed on CITES Appendix II. In light of these listings, we review the Queensland Sea Cucumber Fishery, which harvests CITES-listed black teatfish (Holothuria whitmaei) and white teatfish (H. fuscogilva), and other IUCN-species, from the Great Barrier Reef (GBR), Australia. Teatfish harvest on the GBR has experienced serial catch reductions and fishery closure due to local depletion, a trend observed globally for sea cucumbers and of concern for the at-risk GBR World Heritage Area. We provide the first case study for teatfish while their trade continues, and highlight other species of concern. The major target species of the fishery, Actinopyga spinea (~ 50% of total catch), is not a traditional species in the global trade. With over one million individuals harvested annually, its fishery and its ecological consequences require attention. We synthesise knowledge on teatfish population parameters, identify knowledge gaps and suggest measures to reduce fishery impacts. Continued global exploitation of at-risk marine invertebrate species, coupled with scientific uncertainties, emphasise the urgent need for targeted research and to apply the precautionary principle to avoid detrimental outcomes in their conservation status. • Commercial sea cucumbers are in peril and their fishery on the GBR is reviewed. • CITES-listed species represent >20% of the Queensland fishery and continue to be traded with evidence of stock depletion. • Actinopyga spinea is not traditionally fished globally and its excessive harvest on the GBR is of concern. • There is urgent need for empirical population-fishery parameter data to inform sustainable harvest on the GBR and globally. [ABSTRACT FROM AUTHOR]

The Great Barrier Reef (GBR), Queensland, Australia, is one of the most recognisable coral reefs in the world. In 1981 the reef was listed on the World Heritage List, to be preserved as an environmental asset of global significance for all people in perpetuity. The GBR is also a landmark Marine Protected Area (MPA) under the World Heritage Marine Programme. Yet management of this iconic property is not without controversy and in recent years a number of impacts, including coastal developments, increased shipping traffic and global warming, have all threatened the reef. Any breach of Australia's World Heritage obligation to protect and conserve the property may yet result in the GBR being placed on the World Heritage List in Danger. In light of the persistent controversy surrounding GBR management, this paper gives voice to the perspectives and values of stakeholders located in and around one site of controversy, Gladstone Harbour, in the southern section of the GBR World Heritage Area. We present the views of users directly exposed to the controversial port expansion development at Gladstone Harbour in the southern GBR to shed light on the importance of community perspectives in marine park management. Our findings show that local views act to reinforce the global environmental protection narrative which underpins the World Heritage (WH) system. In this study local and global values collide and, we argue, that overlooking the perspectives of users has potential deleterious consequences for WH marine site management. [ABSTRACT FROM AUTHOR]

Aim: Coral reef communities occurring in deeper waters have received little research effort compared to their shallow-water counterparts, and even such basic information as their location and extent are currently unknown throughout most of the world. Using the Great Barrier Reef as a case study, habitat suitability modelling is used to predict the distribution of deep- water coral reef communities on the Great Barrier Reef, Australia. We test the effectiveness of a range of geophysical and environmental variables for predicting the location of deep-water coral reef communities on the Great Barrier Reef. Location: Great Barrier Reef, Australia. Methods: Maximum entropy modelling is used to identify the spatial extent of two broad communities of habitat-forming megabenthos phototrophs and heterotrophs. Models were generated using combinations of geophysical substrate properties derived from multibeam bathymetry and environmental data derived from Bio-ORACLE, combined with georeferenced occurrence records of mesophotic coral communities from autonomous underwater vehicle, remotely operated vehicle and SCUBA surveys. Model results are used to estimate the total amount of mesophotic coral reef habitat on the GBR. Results: Our models predict extensive but previously undocumented coral communities occurring both along the continental shelf-edge of the Great Barrier Reef and also on submerged reefs inside the lagoon. Habitat suitability for phototrophs is highest on submerged reefs along the outer-shelf and the deeper flanks of emergent reefs inside the GBR lagoon, while suitability for heterotrophs is highest in the deep waters along the shelf-edge. Models using only geophysical variables consistently outperformed models incorporating environmental data for both phototrophs and heterotrophs. Main Conclusion: Extensive submerged coral reef communities that are currently undocumented are likely to occur throughout the Great Barrier Reef. High-quality bathymetry data can be used to identify these reefs, which may play an important role in resilience of the GBR ecosystem to climate change. [ABSTRACT FROM AUTHOR]

Background: The Queensland East Coast Otter Trawl Fishery (ECOTF) for penaeid shrimp fishes within Australia's Great Barrier Reef World Heritage Area (GBRWHA). The past decade has seen the implementation of conservation and fisheries management strategies to reduce the impact of the ECOTF on the seabed and improve biodiversity conservation. New information from electronic vessel location monitoring systems (VMS) provides an opportunity to review the interactions between the ECOTF and spatial closures for biodiversity conservation. Methodology and Results: We used fishing metrics and spatial information on the distribution of closures and modelled VMS data in a geographical information system (GIS) to assess change in effort of the trawl fishery from 2001-2009 and to quantify the exposure of 70 reef, non-reef and deep water bioregions to trawl fishing. The number of trawlers and the number of days fished almost halved between 2001 and 2009 and new spatial closures introduced in 2004 reduced the area zoned available for trawl fishing by 33%. However, we found that there was only a relatively minor change in the spatial footprint of the fishery as a result of new spatial closures. Non-reef bioregions benefited the most from new spatial closures followed by deep and reef bioregions. Conclusions/Significance: Although the catch of non target species remains an issue of concern for fisheries management, the small spatial footprint of the ECOTF relative to the size of the GBRWHA means that the impact on benthic habitats is likely to be negligible. The decline in effort as a result of fishing industry structural adjustment, increasing variable costs and business decisions of fishers is likely to continue a trend to fish only in the most productive areas. This will provide protection for most benthic habitats without any further legislative or management intervention. [ABSTRACT FROM AUTHOR]

Conventional perceptions of the interactions between people and their environment are rapidly transforming. Old paradigms that view humans as separate from nature, natural resources as inexhaustible or endlessly substitutable, and the world as stable, predictable, and in balance are no longer tenable. New conceptual frameworks are rapidly emerging based on an adaptive approach that focuses on learning and flexible management in a dynamic social-ecological landscape. Using two iconic World Heritage Areas as case studies (the Great Barrier Reef and the Grand Canyon) we outline how an improved integration of the scientific and social aspects of natural resource management can guide the evolution of multiscale systems of governance that confront and cope with uncertainty, risk, and change in an increasingly human-dominated world. [ABSTRACT FROM AUTHOR]

The potential of fertilized cropping soils (sugarcane, vegetables, fruit trees) in river catchments that drain to the Great Barrier Reef World Heritage Area in northeastern Australia to release soluble phosphorus (P) was assessed using soil chemical tests on typical soils (0–10 cm) collected in 2003. Tests included total P, diagnostic soil P tests, estimates of P buffering, and soluble and redox sensitive soil P. Routine soil P tests proved poor predictors of CaCl2 P (0.005 M). Values&nvge;0.20 for the Mehlich‐3 P saturation ratio separated (P<0.01) lower from higher concentrations of CaCl2 P. The ratio of Mehlich‐3 Fe to [Mehlich‐3 Fe+Mehlich‐3 Al] is offered as a possible simple index of redox sensitive P. Part 1 (Rayment and Bloesch 2006) describes the soil survey in more detail. [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]

Seagrass meadows are an important habitat for a variety of animals, including ecologically and socioeconomically important species. Seagrass meadows are recognised as providing species with nursery grounds, and as a migratory pathway to adjacent habitats. Despite their recognised importance, little is known about the species assemblages that occupy seagrass meadows of different depths in the coastal zone. Understanding differences in the distribution of species in seagrass at different depths, and differences in species diversity, abundance, biomass, and size spectra, is important to fully appreciate both the ecological significance and economic importance of these seagrass meadows. Here, we assess differences in the assemblage characteristics of fish, crustacea, and cephalopods (collectively, nekton) between deep (>9 m; Halophila spinulosa dominant) and shallow water (<2 m; Halodule uninervis and/or Zostera muelleri dominant) seagrass meadows of the central Great Barrier Reef coast of Queensland, Australia. Nekton assemblage structure differed between deep and shallow seagrass. Deeper meadows were typified by juvenile emperors (e.g., Lethrinus genivittatus), hairfinned leatherjacket (Paramonacanthus japonicus) and rabbitfish (e.g., Siganus fuscescens) in both biomass per unit effort (BPUE) and catch per unit effort (CPUE), whereas shallow meadows were typified by the green tiger prawn (Penaeus semisulcatus) and pugnose ponyfish (Secutor insidiator) in both BPUE and CPUE. Both meadow depths were distinct in their nekton assemblage, particularly for socioeconomically important species, with 11 species unique to both shallow and deep meadows. However, both meadow depths also included juveniles of socioeconomically important species found in adjacent habitats as adults. The total nekton CPUE was not different between deep and shallow seagrass, but the BPUE and body mass of individual animals were greater in deep than shallow seagrass. Size spectra analysis indicated that in both deep and shallow meadows, smaller animals predominated, even more so than theoretically expected for size spectra. Our findings highlight the unique attributes of both shallow and deeper water seagrass meadows, and identify the distinct and critically important role of deep seagrass meadows within the Great Barrier Reef World Heritage Area (GBRWHA) as a habitat for small and juvenile species, including those of local fisheries value. [ABSTRACT FROM AUTHOR]

The Great Barrier Reef is a UNESCO World Heritage Area that has been assessed as having a very poor outlook and needing urgent intervention. The eReefs hydrodynamic-biogeochemical models are used to complement monitoring, facilitate data interpretation and support policy decisions. Management and policy for the Great Barrier Reef are politically contentious, so a high standard of model evaluation is required. We report the application of a recently-developed four-level "CSPS" (Concept/State/Process/System) model evaluation framework to the eReefs biogeochemical model. The framework considers: Level 0, conceptual evaluation; Level 1, simulated state variables; Level 2, process rates; and Level 3, system-level patterns and emergent properties. This paper is the first complete application of this model assessment framework. It highlights both strengths and weaknesses of the eReefs biogeochemical model that might not have been apparent from a traditional model evaluation. The framework can be applied to evaluation of any complex, process-based numerical model. • In politically-contentious contexts, models require a high standard of assessment. • We demonstrate the four-level (Concept/State/Process/System) assessment framework. • The performance of the eReefs marine models is assessed. • The approach highlights strengths and weaknesses of the models. • Emergent properties are particularly useful to enhance model assessment. [ABSTRACT FROM AUTHOR]

Great Barrier Reef catchments are under pressure from the effects of climate change, landscape modifications, and hydrology alterations. With the use of remote sensing datasets covering large areas, conventional methods of change detection can expose broad transitions, whereas workflows that excerpt data for time-series trends divulge more subtle transformations of land cover modification. Here, we combine both these approaches to investigate change and trends in a large estuarine region of Central Queensland, Australia, that encompasses a national park and is adjacent to the Great Barrier Reef World Heritage site. Nine information classes were compiled in a maximum likelihood post classification change analysis in 2004–2017. Mangroves decreased (1146 hectares), as was the case with estuarine wetland (1495 hectares), and saltmarsh grass (1546 hectares). The overall classification accuracies and Kappa coefficient for 2004, 2006, 2009, 2013, 2015, and 2017 land cover maps were 85%, 88%, 88%, 89%, 81%, and 92%, respectively. The cumulative area of open forest, estuarine wetland, and saltmarsh grass (1628 hectares) was converted to pasture in a thematic change analysis showing the "from–to" change. We generated linear regression relationships to examine trends in pixel values across the time series. Our findings from a trend analysis showed a decreasing trend (p value range = 0.001–0.099) in the vegetation extent of open forest, fringing mangroves, estuarine wetlands, saltmarsh grass, and grazing areas, but this was inconsistent across the study site. Similar to reports from tropical regions elsewhere, saltmarsh grass is poorly represented in the national park. A severe tropical cyclone preceding the capture of the 2017 Landsat 8 Operational Land Imager (OLI) image was likely the main driver for reduced areas of shoreline and stream vegetation. Our research contributes to the body of knowledge on coastal ecosystem dynamics to enable planning to achieve more effective conservation outcomes. [ABSTRACT FROM AUTHOR]

Gully erosion is a dominant source of sediment and particulates to the Great Barrier Reef (GBR) World Heritage area. We selected the Bowen catchment, a tributary of the Burdekin Basin, as our area of study; the region is associated with a high density of gully networks. We aimed to use a semi-automated object-based gully networks detection process using a combination of multi-source and multi-scale remote sensing and ground-based data. An advanced approach was employed by integrating geographic object-based image analysis (GEOBIA) with current machine learning (ML) models. These included artificial neural networks (ANN), support vector machines (SVM), and random forests (RF), and an ensemble ML model of stacking to deal with the spatial scaling problem in gully networks detection. Spectral indices such as the normalized difference vegetation index (NDVI) and topographic conditioning factors, such as elevation, slope, aspect, topographic wetness index (TWI), slope length (SL), and curvature, were generated from Sentinel 2A images and the ALOS 12-m digital elevation model (DEM), respectively. For image segmentation, the ESP2 tool was used to obtain three optimal scale factors. On using object pureness index (OPI), object matching index (OMI), and object fitness index (OFI), the accuracy of each scale in image segmentation was evaluated. The scale parameter of 45 with OFI of 0.94, which is a combination of OPI and OMI indices, proved to be the optimal scale parameter for image segmentation. Furthermore, segmented objects based on scale 45 were overlaid with 70% and 30% of a prepared gully inventory map to select the ML models' training and testing objects, respectively. The quantitative accuracy assessment methods of Precision, Recall, and an F1 measure were used to evaluate the model's performance. Integration of GEOBIA with the stacking model using a scale of 45 resulted in the highest accuracy in detection of gully networks with an F1 measure value of 0.89. Here, we conclude that the adoption of optimal scale object definition in the GEOBIA and application of the ensemble stacking of ML models resulted in higher accuracy in the detection of gully networks. [ABSTRACT FROM AUTHOR]

The article reports that Great Barrier Reef (GBR) in Australia will retain its status as a United Nations Organization for Education, Science and Culture (UNESCO) World Heritage Area but may be listed as in danger by the organization if Australia does not demonstrate progress in protecting it.

The Great Barrier Reef World Heritage Area (GBRWHA) includes one of the world's largest areas of seagrass (35,000 km 2 ) encompassing approximately 20% of the world's species. Mapping and monitoring programs sponsored by the Australian and Queensland Governments and Queensland Port Authorities have tracked a worrying decrease in abundance and area since 2007. This decline has almost certainly been the result of a series of severe tropical storms and associated floods exacerbating existing human induced stressors. A complex variety of marine and terrestrial management actions and plans have been implemented to protect seagrass and other habitats in the GBRWHA. For seagrasses, these actions are inadequate. They provide an impression of effective protection of seagrasses; reduce the sense of urgency needed to trigger action; and waste the valuable and limited supply of “conservation capital”. There is a management focus on ports, driven by public concerns about high profile development projects, which exaggerates the importance of these relatively concentrated impacts in comparison to the total range of threats and stressors. For effective management of seagrass at the scale of the GBRWHA, more emphasis needs to be placed on the connectivity between seagrass meadow health, watersheds, and all terrestrial urban and agricultural development associated with human populations. The cumulative impacts to seagrass from coastal and marine processes in the GBRWHA are not evenly distributed, with a mosaic of high and low vulnerability areas. This provides an opportunity to make choices for future coastal development plans that minimise stress on seagrass meadows. [ABSTRACT FROM AUTHOR]