Department of Climate Change, Energy, the Environment and Water

Abstract As the United Nations develops a post-2020 global biodiversity framework for the Convention on Biological Diversity, attention is focusing on how new goals and targets for ecosystem conservation might serve its vision of ‘living in harmony with nature’ 1,2 . Advancing dual imperatives to conserve biodiversity and sustain ecosystem services requires reliable and resilient generalizations and predictions about ecosystem responses to environmental change and management 3 . Ecosystems vary in their biota 4 , service provision 5 and relative exposure to risks 6 , yet there is no globally consistent classification of ecosystems that reflects functional responses to change and management. This hampers progress on developing conservation targets and sustainability goals. Here we present the International Union for Conservation of Nature (IUCN) Global Ecosystem Typology, a conceptually robust, scalable, spatially explicit approach for generalizations and predictions about functions, biota, risks and management remedies across the entire biosphere. The outcome of a major cross-disciplinary collaboration, this novel framework places all of Earth’s ecosystems into a unifying theoretical context to guide the transformation of ecosystem policy and management from global to local scales. This new information infrastructure will support knowledge transfer for ecosystem-specific management and restoration, globally standardized ecosystem risk assessments, natural capital accounting and progress on the post-2020 global biodiversity framework.

Genetic diversity among and within populations of all species is necessary for people and nature to survive and thrive in a changing world. Over the past three years, commitments for conserving genetic diversity have become more ambitious and specific under the Convention on Biological Diversity's (CBD) draft post-2020 global biodiversity framework (GBF). This Perspective article comments on how goals and targets of the GBF have evolved, the improvements that are still needed, lessons learned from this process, and connections between goals and targets and the actions and reporting that will be needed to maintain, protect, manage and monitor genetic diversity. It is possible and necessary that the GBF strives to maintain genetic diversity within and among populations of all species, to restore genetic connectivity, and to develop national genetic conservation strategies, and to report on these using proposed, feasible indicators.

Abstract Antarctic landfast sea ice (fast ice) is stationary sea ice that is attached to the coast, grounded icebergs, ice shelves, or other protrusions on the continental shelf. Fast ice forms in narrow (generally up to 200 km wide) bands, and ranges in thickness from centimeters to tens of meters. In most regions, it forms in autumn, persists through the winter and melts in spring/summer, but can remain throughout the summer in particular locations, becoming multi‐year ice. Despite its relatively limited extent (comprising between about 4% and 13% of overall sea ice), its presence, variability and seasonality are drivers of a wide range of physical, biological and biogeochemical processes, with both local and far‐ranging ramifications for the Earth system. Antarctic fast ice has, until quite recently, been overlooked in studies, likely due to insufficient knowledge of its distribution, leading to its reputation as a “missing piece of the Antarctic puzzle.” This review presents a synthesis of current knowledge of the physical, biogeochemical and biological aspects of fast ice, based on the sub‐domains of: fast ice growth, properties and seasonality; remote‐sensing and distribution; interactions with the atmosphere and the ocean; biogeochemical interactions; its role in primary production; and fast ice as a habitat for grazers. Finally, we consider the potential state of Antarctic fast ice at the end of the 21st Century, underpinned by Coupled Model Intercomparison Project model projections. This review also gives recommendations for targeted future work to increase our understanding of this critically‐important element of the global cryosphere.

To understand the scope and scale of the loss of biodiversity, tools are required that can be applied in a standardized manner to all species globally, spanning realms from land to the open ocean. We used data from the International Union for the Conservation of Nature Red List to provide a synthesis of the conservation status and extinction risk of cetaceans. One in 4 cetacean species (26% of 92 species) was threatened with extinction (i.e., critically endangered, endangered, or vulnerable) and 11% were near threatened. Ten percent of cetacean species were data deficient, and we predicted that 2-3 of these species may also be threatened. The proportion of threatened cetaceans has increased: 15% in 1991, 19% in 2008, and 26% in 2021. The assessed conservation status of 20% of species has worsened from 2008 to 2021, and only 3 moved into categories of lesser threat. Cetacean species with small geographic ranges were more likely to be listed as threatened than those with large ranges, and those that occur in freshwater (100% of species) and coastal (60% of species) habitats were under the greatest threat. Analysis of odontocete species distributions revealed a global hotspot of threatened small cetaceans in Southeast Asia, in an area encompassing the Coral Triangle and extending through nearshore waters of the Bay of Bengal, northern Australia, and Papua New Guinea and into the coastal waters of China. Improved management of fisheries to limit overfishing and reduce bycatch is urgently needed to avoid extinctions or further declines, especially in coastal areas of Asia, Africa, and South America.

Abstract Recent scientific evidence shows that genetic diversity must be maintained, managed, and monitored to protect biodiversity and nature's contributions to people. Three genetic diversity indicators, two of which do not require DNA‐based assessment, have been proposed for reporting to the Convention on Biological Diversity and other conservation and policy initiatives. These indicators allow an approximation of the status and trends of genetic diversity to inform policy, using existing demographic and geographic information. Application of these indicators has been initiated and here we describe ongoing efforts in calculating these indicators with examples. We specifically describe a project underway to apply these indicators in nine countries, provide example calculations, address concerns of policy makers and implementation challenges, and describe a roadmap for further development and deployment, incorporating feedback from the broader community. We also present guidance documents and data collection tools for calculating indicators. We demonstrate that Parties can successfully and cost‐effectively report these genetic diversity indicators with existing biodiversity observation data, and, in doing so, better conserve the Earth's biodiversity.

Abstract Agricultural ponds have some of the highest methane emissions per area among freshwater systems, and these anthropogenic emissions should be included in national greenhouse gas inventories. Here we deliver a continental-scale assessment of methane emissions from agricultural ponds in the United States and Australia. We source maps of agricultural ponds, compile a meta-analysis for their emissions and use published data to correct for temperature and the relative contributions of two methane fluxes (diffusion and ebullition). In the United States, 2.56 million agricultural ponds cover 420.9 kha and emit about 95.8 kt year −1 of methane. In Australia, 1.76 million agricultural ponds cover 291.2 kha and emit about 75.1 kt year −1 of methane. Despite large uncertainties, our findings suggest that small water bodies emit twice as much methane than is currently accounted for in national inventories. Managing these systems can reduce these emissions while benefiting productivity, ecosystem services, and biodiversity.

Under the recently adopted Kunming-Montreal Global Biodiversity Framework, 196 Parties committed to reporting the status of genetic diversity for all species. To facilitate reporting, three genetic diversity indicators were developed, two of which focus on processes contributing to genetic diversity conservation: maintaining genetically distinct populations and ensuring populations are large enough to maintain genetic diversity. The major advantage of these indicators is that they can be estimated with or without DNA-based data. However, demonstrating their feasibility requires addressing the methodological challenges of using data gathered from diverse sources, across diverse taxonomic groups, and for countries of varying socio-economic status and biodiversity levels. Here, we assess the genetic indicators for 919 taxa, representing 5271 populations across nine countries, including megadiverse countries and developing economies. Eighty-three percent of the taxa assessed had data available to calculate at least one indicator. Our results show that although the majority of species maintain most populations, 58% of species have populations too small to maintain genetic diversity. Moreover, genetic indicator values suggest that IUCN Red List status and other initiatives fail to assess genetic status, highlighting the critical importance of genetic indicators.

Sea ice is a key habitat in the high latitude Southern Ocean and is predicted to change in its extent, thickness and duration in coming decades. The sea-ice cover is instrumental in mediating ocean–atmosphere exchanges and provides an important substrate for organisms from microbes and algae to predators. Antarctic krill, Euphausia superba, is reliant on sea ice during key phases of its life cycle, particularly during the larval stages, for food and refuge from their predators, while other small grazers, including copepods and amphipods, either live in the brine channel system or find food and shelter at the ice-water interface and in gaps between rafted ice blocks. Fish, such as the Antarctic silverfish Pleuragramma antarcticum , use platelet ice (loosely-formed frazil crystals) as an essential hatching and nursery ground. In this paper, we apply the framework of the Marine Ecosystem Assessment for the Southern Ocean (MEASO) to review current knowledge about relationships between sea ice and associated primary production and secondary consumers, their status and the drivers of sea-ice change in this ocean. We then use qualitative network modelling to explore possible responses of lower trophic level sea-ice biota to different perturbations, including warming air and ocean temperatures, increased storminess and reduced annual sea-ice duration. This modelling shows that pelagic algae, copepods, krill and fish are likely to decrease in response to warming temperatures and reduced sea-ice duration, while salp populations will likely increase under conditions of reduced sea-ice duration and increased number of days of >0°C. Differences in responses to these pressures between the five MEASO sectors were also explored. Greater impacts of environmental pressures on ice-related biota occurring presently were found for the West and East Pacific sectors (notably the Ross Sea and western Antarctic Peninsula), with likely flow-on effects to the wider ecosystem. All sectors are expected to be impacted over coming decades. Finally, we highlight priorities for future sea ice biological research to address knowledge gaps in this field.

Antarctic terrestrial biodiversity faces multiple threats, from invasive species to climate change. Yet no large-scale assessments of threat management strategies exist. Applying a structured participatory approach, we demonstrate that existing conservation efforts are insufficient in a changing world, estimating that 65% (at best 37%, at worst 97%) of native terrestrial taxa and land-associated seabirds are likely to decline by 2100 under current trajectories. Emperor penguins are identified as the most vulnerable taxon, followed by other seabirds and dry soil nematodes. We find that implementing 10 key threat management strategies in parallel, at an estimated present-day equivalent annual cost of US$23 million, could benefit up to 84% of Antarctic taxa. Climate change is identified as the most pervasive threat to Antarctic biodiversity and influencing global policy to effectively limit climate change is the most beneficial conservation strategy. However, minimising impacts of human activities and improved planning and management of new infrastructure projects are cost-effective and will help to minimise regional threats. Simultaneous global and regional efforts are critical to secure Antarctic biodiversity for future generations.

Thousands of oil and gas structures have been installed in the world's oceans over the past 70 years to meet the population's reliance on hydrocarbons. Over the last decade, there has been increased concern over how to handle decommissioning of this infrastructure when it reaches the end of its operational life. Complete or partial removal may or may not present the best option when considering potential impacts on the environment, society, technical feasibility, economy, and future asset liability. Re-purposing of offshore structures may also be a valid legal option under international maritime law where robust evidence exists to support this option. Given the complex nature of decommissioning offshore infrastructure, a global horizon scan was undertaken, eliciting input from an interdisciplinary cohort of 35 global experts to develop the top ten priority research needs to further inform decommissioning decisions and advance our understanding of their potential impacts. The highest research priorities included: (1) an assessment of impacts of contaminants and their acceptable environmental limits to reduce potential for ecological harm; (2) defining risk and acceptability thresholds in policy/governance; (3) characterising liability issues of ongoing costs and responsibility; and (4) quantification of impacts to ecosystem services. The remaining top ten priorities included: (5) quantifying ecological connectivity; (6) assessing marine life productivity; (7) determining feasibility of infrastructure re-use; (8) identification of stakeholder views and values; (9) quantification of greenhouse gas emissions; and (10) developing a transdisciplinary decommissioning decision-making process. Addressing these priorities will help inform policy development and governance frameworks to provide industry and stakeholders with a clearer path forward for offshore decommissioning. The principles and framework developed in this paper are equally applicable for informing responsible decommissioning of offshore renewable energy infrastructure, in particular wind turbines, a field that is accelerating rapidly.

Closely related species often use the same genes to adapt to similar environments. However, we know little about why such genes possess increased adaptive potential and whether this is conserved across deeper evolutionary lineages. Adaptation to climate presents a natural laboratory to test these ideas, as even distantly related species must contend with similar stresses. Here, we re-analyse genomic data from thousands of individuals from 25 plant species as diverged as lodgepole pine and Arabidopsis (~300 Myr). We test for genetic repeatability based on within-species associations between allele frequencies in genes and variation in 21 climate variables. Our results demonstrate significant statistical evidence for genetic repeatability across deep time that is not expected under randomness, identifying a suite of 108 gene families (orthogroups) and gene functions that repeatedly drive local adaptation to climate. This set includes many orthogroups with well-known functions in abiotic stress response. Using gene co-expression networks to quantify pleiotropy, we find that orthogroups with stronger evidence for repeatability exhibit greater network centrality and broader expression across tissues (higher pleiotropy), contrary to the 'cost of complexity' theory. These gene families may be important in helping wild and crop species cope with future climate change, representing important candidates for future study.

Co-design, co-development, and co-delivery (Co-3D for short) are activities within the co-production research pathway that are increasingly being used in climate change science and adaptation projects. However, the research community is still coming to understand how best to incorporate Co-3D in practice, as each project has a specific context around stakeholder relationships, governance arrangements, and capacity to actively participate. This paper outlines five case studies from Australia as examples of different projects engaging with Co-3D in different ways in order to explore how Co-3D is being used and might be improved. Crucially, we include the perceptions and experiences of researchers, funders and end users, as well as our own critical reflections. Each of the projects self-describes as using ‘co-production’, but the extent and format varies widely with different combinations of co-design, co-development and/or co-delivery used in each. Our findings show that without clear understanding of Co-3D within the co-production process, aspects of Co-3D may not be properly considered in planning or implementation. Co-3D activities are not completely distinct, rather they form a continuum of engagement and integration across phases of project work. Thus, the specific definitions and delineations between these terms may not be required for them to be applied. However, practical and explicit negotiation of what ‘co-production’ means in different project contexts is needed so that all parties understand their roles and responsibilities. Further, more evaluations of outcomes and stakeholder experiences are required. We provide seven principles of Co-3D that should be considered when embarking on co-production projects.

Abstract Environmental DNA (eDNA)‐based methods are increasingly used by government agencies to detect pests and threatened species, and for broader biodiversity monitoring. Given rapid technological advances and a growing number of commercial service providers, there is a need to standardize methods for quality assurance and to maintain confidence in eDNA‐based results. Here, we introduce two documents to provide best‐practice guidelines for Australian and New Zealand eDNA researchers and end‐users (available from https://sednasociety.com/publications ): the Environmental DNA protocol development guide for biomonitoring provides minimum standard considerations for eDNA and environmental RNA projects across the complete workflow, from ethical considerations and experimental design to interpreting and communicating results. The Environmental DNA test validation guidelines outline key steps to be used in assay development and validation for species‐specific testing and metabarcoding. Both guidelines were developed as an initiative of the Australian Government Department of Agriculture, Fisheries and Forestry and led by the Southern eDNA Society in a collaborative process including multiple consultation rounds with eDNA experts, end‐users, and stakeholders to adapt the guidelines to Australian and New Zealand needs. The aim of these guidelines is not to be prescriptive, but to set minimum standards to support a consistent and best‐practice approach to eDNA testing. We anticipate that the guidelines will be reviewed and regularly updated as required. Our aspiration is that these best‐practice guidelines will ensure environmental managers are provided with robust scientific evidence to support decision‐making.

Polar oceans and sea ice cover 15% of the Earth’s ocean surface, and the environment is changing rapidly at both poles. Improving knowledge on the interactions between the atmospheric and oceanic realms in the polar regions, a Surface Ocean–Lower Atmosphere Study (SOLAS) project key focus, is essential to understanding the Earth system in the context of climate change. However, our ability to monitor the pace and magnitude of changes in the polar regions and evaluate their impacts for the rest of the globe is limited by both remoteness and sea-ice coverage. Sea ice not only supports biological activity and mediates gas and aerosol exchange but can also hinder some in-situ and remote sensing observations. While satellite remote sensing provides the baseline climate record for sea-ice properties and extent, these techniques cannot provide key variables within and below sea ice. Recent robotics, modeling, and in-situ measurement advances have opened new possibilities for understanding the ocean–sea ice–atmosphere system, but critical knowledge gaps remain. Seasonal and long-term observations are clearly lacking across all variables and phases. Observational and modeling efforts across the sea-ice, ocean, and atmospheric domains must be better linked to achieve a system-level understanding of polar ocean and sea-ice environments. As polar oceans are warming and sea ice is becoming thinner and more ephemeral than before, dramatic changes over a suite of physicochemical and biogeochemical processes are expected, if not already underway. These changes in sea-ice and ocean conditions will affect atmospheric processes by modifying the production of aerosols, aerosol precursors, reactive halogens and oxidants, and the exchange of greenhouse gases. Quantifying which processes will be enhanced or reduced by climate change calls for tailored monitoring programs for high-latitude ocean environments. Open questions in this coupled system will be best resolved by leveraging ongoing international and multidisciplinary programs, such as efforts led by SOLAS, to link research across the ocean–sea ice–atmosphere interface.

Catastrophic megafires can increase extinction risks; identifying species priorities for management and policy support is critical for preparing and responding to future fires. However, empirical data on population loss and recovery post-fire, especially megafire, are limited and taxonomically biased. These gaps could be bridged if species' morphological, behavioural, ecological and life history traits indicated their fire responses. Using expert elicitation that estimated population changes following the 2019–20 Australian megafires for 142 terrestrial and aquatic animal species (from every vertebrate class, one invertebrate group), we examined whether expert estimates of fire-related mortality, mortality in the year post-fire, and recovery trajectories over 10 years/three generations post-fire, were related to species traits. Expert estimates for fire-related mortality were lower for species that could potentially flee or shelter from fire, and that associated with fire-prone habitats. Post-fire mortality estimates were linked to diet, diet specialisation, home range size, and susceptibility to introduced herbivores that damage or compete for resources. Longer-term population recovery estimates were linked to diet/habitat specialisation, susceptibility to introduced species; species with slower life histories and shorter subadult dispersal distances also had lower recovery estimates. Across animal groups, experts estimated that recovery was poorest for species with pre-fire population decline and more threatened conservation status. Sustained management is likely needed to recover species with habitat and diet specialisations, slower life histories, pre-existing declines and threatened conservation statuses. This study shows that traits could help inform management priorities before and after future megafires, but further empirical data on animal fire response is essential.

Abstract Molecular tools are increasingly applied for assessing and monitoring biodiversity and informing conservation action. While recent developments in genetic and genomic methods provide greater sensitivity in analysis and the capacity to address new questions, they are not equally available to all practitioners: There is considerable bias across institutions and countries in access to technologies, funding, and training. Consequently, in many cases, more accessible traditional genetic data (e.g., microsatellites) are still utilized for making conservation decisions. Conservation approaches need to be pragmatic by tackling clearly defined management questions and using the most appropriate methods available, while maximizing the use of limited resources. Here we present some key questions to consider when applying the molecular toolbox for accessible and actionable conservation management. Finally, we highlight a number of important steps to be addressed in a collaborative way, which can facilitate the broad integration of molecular data into conservation.

Desires that mine sites are restored to self‐sustaining native ecosystems providing benefits for people have been longstanding. However, achieving and demonstrating progress toward mine restoration goals is complex and requires sustained assessment of numerous disparate components. The recently released Society for Ecological Restoration Mine Site Restoration Standards (SER MSRS) recommend utilizing restoration science assessments to determine whether sites are developing toward similarity with targeted ecosystems and exhibiting self‐sustainability. We conducted a global review of publications that assessed restoration to native ecosystems after mining. Our objectives were to (1) document case studies of long‐term assessments of mine restoration and (2) evaluate the extent to which restoration assessment has reported the achievement of varied mine restoration goals on a global scale, including (3) whether any ecosystem components and restoration attributes are underrepresented in published assessments. Among the 712 publications we collated, we documented case studies with sustained reporting on similar restoration and significant increase over time in the quantity and breadth of attributes and ecosystems assessed. Nevertheless, notable gaps remain, or underreporting persists. For example, there have been relatively few assessments targeting understanding of key ecosystem processes, resilience, and threats to ecosystem persistence that are necessary for demonstrating “self‐sustainability.” Our review also revealed limited consideration of ecosystem services that rarely involved impacted communities. We recommend efforts to collate and expand assessments of similar restoration trajectories, placing more focus on indicators that enable the evaluation of characteristics and progress toward a self‐sustaining socioecological ecosystem, to help achieve the goals of mine site restoration.

Standard proxies for reconstructing surface mass balance (SMB) in Antarctic ice cores are often inaccurate or coarsely resolved when applied to more complicated environments away from dome summits. Here, we propose an alternative SMB proxy based on photolytic fractionation of nitrogen isotopes in nitrate observed at 114 sites throughout East Antarctica. Applying this proxy approach to nitrate in a shallow core drilled at a moderate SMB site (Aurora Basin North), we reconstruct 700 years of SMB changes that agree well with changes estimated from ice core density and upstream surface topography. For the under-sampled transition zones between dome summits and the coast, we show that this proxy can provide past and present SMB values that reflect the immediate local environment and are derived independently from existing techniques.

Wetland area and condition are declining globally despite their importance to climate change mitigation and biodiversity. Introduced ungulate species are contributing to the global decline. Their impacts on wetlands are widespread and varied, however poorly understood. We summarise global impacts of introduced unmanaged and domesticated ungulates on wetlands highlighting potential outcomes of their removal. We place an emphasis on Australia due to the disproportionate impacts of ungulates on wetlands and potential for emerging carbon and biodiversity markets to incentivise private investment in wetland conservation and restoration. Our Systematic Literature Review assessed impacts of cattle, pigs, horses, deer, buffalo, sheep, camels, and other ungulates on wetlands. There were 372 relevant resources from 35 countries, with highest representation from Australia and the United States. The majority related to cattle (29 %) and pigs (19 %). More impacts were reported in freshwater wetlands (51 %) than marine (19 %). A quarter of studies related to riparian habitats. Ungulate impacts varied geographically and among climates. More studies reported soil damage, weed dispersal, decreased vegetation cover, and woody vegetation suppression than neutral or positive changes in these metrics. Decreases in richness and abundance of native flora and fauna were more frequently reported than increases. Of 33 studies reporting wetland carbon impacts, 24 reported increased CO2 emissions due to loss of soil carbon or vegetation biomass. Ungulate exclusion from wetlands could enhance carbon stocks and biodiversity, however further studies comparing wetland typologies and carbon dynamics are needed to quantify levels of enhancement given differences in ungulate species and environments.

As the use of coastal and offshore environments expands, there is a need to better understand the exposure of marine megafauna to anthropogenic activities that potentially threaten their populations. Individual satellite telemetry studies are often hampered by small sample sizes, providing limited information on spatiotemporal distributions of migratory animals and their relationships to anthropogenic threats. We addressed this issue by synthesising satellite tracking data from 484 individuals of three taxonomic groups and six species; three marine turtle, two whale and one shark. The spatial overlap between taxa distributions and multiple anthropogenic activities was assessed as a proxy for the cumulative exposure of these taxa to anthropogenic threats (coastal modification, vessel strike, underwater noise, oil spill, bycatch, entanglement, and artificial light) across an area totalling 2,205,740 km 2 off north-western Australia. Core exposure areas (top 50% of the distribution) encompassed ecologically important sites for all taxa, such as the Ningaloo and Pilbara regions, migratory routes for whales and sharks in offshore waters beyond Ningaloo Reef, and marine turtle nesting beaches at Barrow Island and Cape Lambert. Although areas of high exposure represented <14% of taxa distributions, we showed that no taxa occurred in the absence of threats and that even areas with existing spatial protections are experiencing high levels of exposure. Importantly, we developed a robust approach for documenting the potential exposure of marine species to a range of human activities at appropriate spatial scales to inform conservation management.