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Habitat loss is a key driver of species extinction, demanding effective policies to regulate land clearing and mitigate this threat. This study examines the impact of policy changes on the availability of vegetation for clearing in Queensland, Australia, focusing on three policy variants from 2012, 2015, and 2019. Our analysis highlights significant shifts in remnant vegetation availability. In 2015, the introduction of permissions for clearing native vegetation for agricultural and pastoral production resulted in an additional 84 million ha of remnant vegetation becoming available for clearing. Furthermore, changes made in 2015 decreased riparian buffer zones, further expanding the extent of remnant vegetation on which clearing for specific purposes is permissible. Between 2015 and 2019, we identified five policy changes with substantial implications for vegetation management, including revoking permission for establishing broad acre cropping or grazing properties and removing thinning as a relevant clearing purpose. While the 2019 guidelines provide increased protection for remnant vegetation, it's crucial to note that all policy changes took place within a relatively brief period. Sudden policy changes can disrupt existing land management practices and strategies, potentially leading to confusion and challenges in adapting to new regulations and requirements. Our findings underscore the need to consider the ecological effects of rapid policy changes, as underestimating their overall impact on vegetation can have far-reaching implications for species preservation and ecosystem health. • This research highlights that changes in land clearing policies and guidelines substantially impact the potential extent of land clearing. • Comprehensive spatial impact assessments are critical evaluations of policy changes related to land management. • Dynamic land management policies introduces large changes in areas regulated for land clearing purposes. [ABSTRACT FROM AUTHOR]

Legislation to ban the targeted fishing of sharks is frequently employed within developing coastal nations. These Shark Large Marine Protected Areas (SLMPAs) are established primarily to alleviate the direct threats that humans pose to sharks through activities such as overfishing and destructive fishing practices. However, despite the anthropogenic nature of these threats, socioeconomic factors are often given less consideration than their ecological counterparts when designating SLMPAs. In this paper, we identified and examined relevant national-level socioeconomic data to determine the challenges and opportunities associated with implementing SLMPAs, focussing on least developed and low income countries. We aimed to use these socioeconomic data to identify nations where SLMPAs are more likely to be successful in providing conservation benefits to sharks. We used principal component analysis to develop two national-level indices that represent these anticipated opportunities and challenges for implementing SLMPAs across 87 coastal nations. The Opportunity Index identifies those nations in which socioeconomic conditions such as adaptive capacity, and strong and fair governance, are favourable for SLMPAs to provide conservation benefits to sharks. The Challenge Index identifies those nations that may not yet be in a position developmentally to support communities to adapt to a loss of access to resources associated with SLMPAs, or to manage and enforce broad scale restrictive legislation. In combination with biophysical considerations, the Challenge and Opportunity indices presented here can support policy makers in deciding whether, and in what cases, SLMPAs are the most appropriate measure to provide conservation benefits to sharks. • Socioeconomic factors are often neglected when planning shark conservation strategies. • Shark large MPAs are not always appropriate conservation tools to benefit sharks. • Adaptive capacity & fair governance are vital for shark large MPAs to benefit sharks. • Low education & high corruption are detrimental for shark large MPAs to be beneficial. • Socioeconomic resilience should be built prior to shark large MPA implementation. [ABSTRACT FROM AUTHOR]

Carbonate production on coral reefs is responsible for the provision of beach sands, for the maintenance of seawater chemical balances and for the growth of reef structure and associated habitat complexity. Key carbonate producers including hard coral, crustose coralline algae, foraminiferal sand and Halimeda were mapped from satellite imagery (spatial resolution 2.5 m, mean overall accuracy = 81%) and an upscaling model was applied to estimate carbonate production. A sensitivity analysis was conducted to evaluate the influence of employing different calcification rates for live coral on the upscaling model. Contemporary coral reef carbonate production for the 21 reef platforms of the Capricorn-Bunker Group (southern Great Barrier Reef) is estimated to be between 489,000 and 659,000 t per year based on seawater chemistry, community composition, calcification rates and reef structural complexity (rugosity). The upscaling model was relatively insensitive to different parameterisations of live coral calcification employed, probably due to live coral being a relatively minor contributor by area (approximately 18% of total reef area throughout the study region). This suggests regional scale seafloor characteristics, such as percentage of area dominated by substrates prone to dissolution (e.g. coral rubble), have a strong bearing on calcium carbonate production and need to be given greater consideration The upscaling framework presented provides a new method for quantifying regional carbonate production that could be applied globally, and provides a valuable baseline against which future changes to carbonate production in this region can be assessed. [ABSTRACT FROM AUTHOR]

The water–energy–food nexus is being promoted as a conceptual tool for achieving sustainable development. Frameworks for implementing nexus thinking, however, have failed to explicitly or adequately incorporate sustainable livelihoods perspectives. This is counterintuitive given that livelihoods are key to achieving sustainable development. In this paper we present a critical review of nexus approaches and identify potential linkages with sustainable livelihoods theory and practice, to deepen our understanding of the interrelated dynamics between human populations and the natural environment. Building upon this review, we explore the concept of ‘environmental livelihood security’ – which encompasses a balance between natural resource supply and human demand on the environment to promote sustainability – and develop an integrated nexus-livelihoods framework for examining the environmental livelihood security of a system. The outcome is an integrated framework with the capacity to measure and monitor environmental livelihood security of whole systems by accounting for the water, energy and food requisites for livelihoods at multiple spatial scales and institutional levels. We anticipate this holistic approach will not only provide a significant contribution to achieving national and regional sustainable development targets, but will also be effective for promoting equity amongst individuals and communities in local and global development agendas. [ABSTRACT FROM AUTHOR]

Marine Protected Areas (MPAs) have the potential to support small-scale fishers in managing their resources. However, a general failure to consider the varying levels of vulnerability of fishers has resulted in MPAs that, often unintentionally, adversely impact small-scale fishers. Furthermore, when fishers lack the capacity to adapt to MPA-related changes, MPAs may fail to meet conservation objectives because fishers do not comply with MPA regulations. In this study, we developed a systematic method to identify individuals who are most vulnerable to being negatively impacted by no-take MPAs through an index that represents individual-level vulnerability. We designed a method for identifying these individuals based on four socioeconomic factors pertaining to vulnerability to MPA changes: livelihood diversity, education, age and wealth, then applied this method in two socially and economically heterogeneous communities in Myanmar's Myeik Archipelago. We used empirical data collected from 80 small-scale fishers in this area to represent each factor, then generated a local-level 'Livelihood Impact Potential Index' (LIPI) that reflects the degree to which a no-take MPA would impact an individual fisher's ability to support his or her livelihood. When attributed to each fisher's most frequented fishing ground, the LIPI can identify locations where no-take MPAs would be most detrimental to small-scale fishers' livelihoods based on their levels of vulnerability. The LIPI can thus be used alongside ecological and commercial fishing data to support planners in designing local-scale MPAs that maximise positive impact on biodiversity and minimise adverse impacts on the most vulnerable fishers in a community. • MPAs often adversely impact fishers if local level vulnerability is not considered. • Linking level of vulnerability to a fishing grounds supports conservation planning. • Fishers with high vulnerability should be supported if their grounds are restricted. • Including vulnerability in MPA planning supports equity in fishing communities. [ABSTRACT FROM AUTHOR]

Contemporary understanding of Holocene coral reef development is based primarily on sub-surface investigations of reef flat, back reef and lagoon zones. Few studies of Holocene fore reef development exist, constituting a significant gap in our understanding of reef evolution. The spur and groove (SaG) zone is a distinct, understudied, feature of fore reefs worldwide. We review SaG development from previous studies and present 29 new SaG short cores with 52 14C and U–Th ages from six fore reef regions of Heron and One Tree reefs, the first such data from the Great Barrier Reef. Remarkably, we found that SaGs do not necessarily accrete in the same direction as their adjacent reef flat. We identified three modes of reef flat and SaG lateral accretion: Mode 1 – lagoonward accretion of both the reef flat and SaGs; Mode 2 –lagoonward accretion of the reef flat but seaward accretion of the SaGs; Mode 3 - seaward accretion of both the reef flat and SaGs. Most SaG zones (five of the six studied) accreted in a seaward direction (Modes 2 or 3). Hydrodynamic conditions and local topography appear to be the dominant factors determining which mode occurs. Episodic high-energy events are also likely to play an important role in SaG formation. Our findings suggest that traditionally held models of reef evolution whereby lagoonal, mature reefs fill, developing into senile platform reefs, may not hold. Rather, reef flats may continue to expand seaward on their leeward, and semi-exposed fronts to increase in size while maintaining their lagoons. • Cores show 3 modes of spur and groove development in southern Great Barrier Reef. • Hydrodynamic conditions and local topography likely determine which mode occurs. • Episodic high-energy events also play an important role in formation. • Most spur and groove zones cored were accreting seaward. • Reef flats may continue to expand seaward while maintaining their lagoons. [ABSTRACT FROM AUTHOR]

Many factors govern reef growth through time, but their relative contributions are commonly poorly known. A prime example is the degree to which modern reef morphology is controlled by contemporary hydrodynamic settings or antecedent topography. Fortunately, reefs record essential information for interpreting palaeoclimate and palaeoenvironment within their structure as they accrete in response to environmental change. Five new cores recovered from the margin of Heron Reef, southern Great Barrier Reef (GBR), provide new insights into Holocene reef development and relationships between Holocene reefs and Pleistocene antecedent topography, suggesting much more irregular underlying topography than expected based on the configuration of the overlying modern reef margin. Cores were recovered to depths of 30 m and 94 new 230 Th ages document growth between 8408 ± 24 and 2222 ± 16 yrs. BP. One core penetrated Pleistocene basement at ∼15.3 m with Holocene reef growth initiated by ∼8.4 ka BP. However, 1.83 km west along the same smooth margin, four cores failed to penetrate Pleistocene basement at depths between 20 and 30 m, suggesting that the margin at this location overlies a karst valley, or alternatively, the antecedent platform does not extend there. A 48 m-long margin-perpendicular transect of three cores documents the filling of this topographic low, at least 30 m beneath the current reef top, with seaward lateral accretion at a rate of 34.3 m/ka. Cores indicate steady vertical and lateral accretion between 3.2 and 1.8 ka BP with no evidence of the hiatus in reef flat progradation seen in most other offshore reefs of the GBR at that time. These cores suggest that the relative protection afforded by the valley allowed for unconsolidated sediment to accumulate, enabling continuous progradation even when other areas of the reef flat appear to have ‘turned off’. Additionally, the cores suggest that although reefs in the southern GBR clearly owe their location to Pleistocene antecedent topography, modern reef morphology at sea level primarily reflects the interaction of Holocene reef communities with contemporary hydrodynamics. [ABSTRACT FROM AUTHOR]

Sediments are ubiquitous on coral reefs. However, studies of reef sediments have largely focused on isolated reservoirs, or processes, and rarely consider hydrodynamic drivers. We therefore provide a quantitative snapshot of sediment dynamics on a coral reef. Across a depth profile, we simultaneously examined: suspended sediments, sediment deposition and accumulation, and hydrodynamic and biological movement processes. We reveal the marked potential for the water column to deliver sediments. Currents carried 12.6 t of sediment over the 2,314 m2 study area in 6 days. Sediment traps suggested that a surprisingly high percentage of this sediment was potentially deposited (5.2%). Furthermore, wave-driven resuspension and reworking by parrotfishes separated a highly dynamic sediment regime on the shallow reef flat (3 m), from a more stagnant reef slope (4.5 m–12 m). This study provides a comprehensive model of how hydrodynamic forces and on-reef processes may shape sediment dynamics on a coral reef. • Suspended sediments and sediment deposition in TurfPods and traps was quantified. • Sediment movement via waves, currents, and parrotfishes was measured concurrently. • Algal turf proxies readily trapped suspended sediments with fast accumulation rates. • Wave energy and parrotfish reworking separated sediment dynamics across habitats. • Replicating our approach spatially and temporally may provide further key insights. [ABSTRACT FROM AUTHOR]