Brendan A. Wintle’s research while affiliated with University of Melbourne and other places

The global extinction crisis is intensifying rapidly, driven by habitat loss, overexploitation, climate change, invasive species, and disease. This unprecedented loss of species not only threatens ecological integrity but also undermines ecosystem services vital for human survival. In response, many countries have set ambitious conservation targets such as halting species extinctions, yet the necessary financial commitments to achieve this are rarely prescribed. Estimating costs can be achieved using an ensemble of spatially variable species-specific cost models for threat abatement activities. We employ this method to provide a cost assessment to halt extinctions for Australia’s priority terrestrial and freshwater species. We show that it will cost ~AUD15.6 billion/year for 30 y to halt extinctions for these 99 priority species (comparable to 1% of Australia’s GDP). The more ambitious objectives to move priority species down one threat category (~AUD103.7 billion/year) or remove from the threatened species list entirely (~AUD157.7 billion/year) would require considerably more investment. Regardless of what is spent, we found that 16 (16%) priority species could not be removed from the threatened species list due to extensive historical declines and pervasive, ongoing, unmanageable threats, such as climate change. But implementing these efforts could ensure conservation benefits for over 43% of all nationally listed nonmarine threatened species. Adequate funding is crucial for meeting government commitments and requires both government leadership and private sector investment.

Context Marine litter is a growing global problem that impacts biodiversity and human societies alike. South-east Asia suffers significant impacts due to high biodiversity, dense human populations, and large volumes of plastics entering the marine environment, primarily through rivers. Aims Drawing on decision-theory principles, Structured Decision Making (SDM) can improve site selection for marine debris management by identifying the best options to reduce plastic exposure to species, ecosystems, and human populations in the marine and coastal environment, as well as an overall reduction of drifting plastic debris in the open ocean. Methods We combine an SDM framework with a plastic transport model and quantify benefits for environmental and social objectives across 542 locations covering 683 rivers along the coasts of south-east Asia in the biodiversity hotspot of the Coral Triangle. We modelled and quantified metrics for the reduction in volume and flow of plastics to all downstream coral reefs, key biodiversity areas, marine protected areas, and coastal communities. Key results No location is the best option across all objectives, but the multiple metrics help to navigate trade-offs across specific objectives. Despite 95% of all plastic debris remaining in circulation in the seascape after 2 months, several rivers contribute not only large volumes of plastic debris to the overall marine pollution but also large volumes of pollution downstream. Conclusions The increasing pollution of the marine environment with plastic debris can only be stopped by regulating and reducing the production of plastic products. However, as long as plastic debris is still circulating in the environment, the identification of these locations where the removal of plastic pollution will deliver the best outcomes for a set of important objectives will remain an important mitigation measure. The proposed framework effectively facilitates understanding existing trade-offs and can easily be adapted to include additional metrics or objectives. Using this framework enables decision-makers to develop a tailor-made prioritisation process for clean-up interventions in their unique socio-ecological contexts. Implications This new decision-science approach for identifying efficient spatial management strategies for plastic clean-up is transferable to any geography and has the capacity to enhance local-to-global plastic management.

Accounting for the cost of repairing the degradation of Earth’s biosphere is critical to guide conservation and sustainable development decisions. Yet the costs of repairing nature through the recovery of a continental suite of threatened species across their range have never been calculated. We estimated the cost of in situ recovery of nationally listed terrestrial and freshwater threatened species (n = 1,657) across the megadiverse continent of Australia by combining the spatially explicit costs of all strategies required to address species-specific threats. Individual species recovery required up to 12 strategies (mean 2.3), predominantly habitat retention and restoration, and the management of fire and invasive species. The estimated costs of maximizing threatened species recovery across Australia varied from AU0–12,626 per ha, depending on the species, threats and context of each location. The total cost of implementing all strategies to recover threatened species in their in situ habitat across Australia summed to an estimated AU$583 billion per year, with management of invasive weeds making up 81% of the total cost. This figure, at 25% of Australia’s GDP, does not represent a realistic biodiversity conservation budget, but needs to be accounted for when weighing up decisions that lead to further costly degradation of Australia’s natural heritage.

Climate and land‐use change pose unprecedented threats to ecosystems, economies, and communities worldwide. To help mitigate the climate crisis, restoration is a rapidly growing industry used to offset carbon emissions. The most common approach is to plant fast‐growing monocultures with the aim of sequestering as much carbon as possible in the shortest time. However, there has been little economic analysis of planting options that explicitly address short and long‐term ecological risks such as fire, disease, and environmental change. Here we develop a method for quantifying ecological risks from fire to sequestration investments and show how these risks can be factored into an analysis of long‐term financial returns relative to opportunity costs. In the case study presented, we find that the apparent advantage of fast‐growing monoculture plantations is likely to be outweighed by the long‐term fire risks to the carbon stored in them. Our analytical framework provides a widely applicable approach to comparing planting options against each other and other land uses, considering key uncertainties. With climate change already manifesting through extreme weather events, rising sea levels, and shifting wildlife populations, our framework can be used to make informed decisions about the best solutions to increase carbon sequestration, reduce ecological risks, and reduce climate impacts with greater certainty.

Indigenous peoples globally are actively seeking better recognition of plants and animals that are of cultural significance, which encompass both species and ecological communities. Acknowledgement and collaborative management of culturally significant entities in biodiversity conservation improves environmental outcomes as well as the health and wellbeing of Indigenous people. The global diversity and complexity of Indigenous knowledge, values and obligations make achieving a universal approach to designating culturally significant entities highly unlikely. Instead, empowering local Indigenous-led governance structures with methods to identify place-based culturally significant entities will yield culturally supported results. Here we used a structured decision-making framework with objectives and biocultural measures developed by Indigenous experts, with the aim of prioritizing place-based culturally significant entities for collaborative management approaches on Bundjalung Country in coastal eastern Australia. We found some congruence and some important differences between culturally significant entities priorities and management compared with the colonial focus of threatened species management underpinned by current laws and policies. We provide reproduceable methods and a demonstration of successful local culturally significant entities designation and prioritization in an Australian context that highlights opportunities for Indigenous leadership, supported by governments in the designation and management of culturally significant entities.

Decision science emphasizes necessary elements required for robust decision‐making. By incorporating decision science principles, frameworks, and tools, it has been demonstrated that decision‐makers can increase the chances of achieving conservation aims. Setting measurable objectives, clearly documenting assumptions about the impact of available actions on a specific threat or problem, explicitly considering constraints, exploring and characterizing uncertainty, and structured deliberation on trade‐offs have been identified as key elements of successful decision‐making. We quantify the extent to which these five elements were utilized in published examples of decision making in conservation in both academic and conservation practice between 2009 and 2018. We found that less than 50% of identified examples included all five elements, with differences in the degree of decision science applied across five commonly used decision support approaches: adaptive management (AM), systematic conservation planning (SCP), structured decision making (SDM), multi‐criteria decision analysis, and cost‐effectiveness analysis. Example applications that utilized the SDM framework were limited in numbers but used on average more than 50% of the five key elements we considered. Although SCP and AM constituted the majority of examples, they were more prevalent in academic studies rather than management applications. SCP and AM examples were widespread in protected area planning, threat abatement, and restoration. Strong geographic bias exists in documented conservation activities that deploy all five decision science elements.