Trade-offs across values in cesspool management highlight challenges to policy making.

On-site Sewage Disposal Systems (OSDS) are globally common, and in Hawai'i they present a risk of contamination to drinking water sources and nearshore waters. State legislation has commanded that all cesspools are to be banned by 2050, thus requiring tens of thousands of systems to be converted in the coming decades. This project followed a participatory structured decision-making (SDM) approach to collaboratively design cost-effective and equitable solutions for thousands of cesspools in the high elevation areas of north Maui, Hawai'i. Participatory workshops with a diverse group of stakeholders set ten objectives and brainstormed 33 alternatives, for which the technical team then modeled groundwater nutrients, costs, and equity. All alternatives posed trade-offs, though composting toilets performed best across most objectives, albeit with high maintenance burden. Discounting innovative toilets, the multi-objective analysis suggests that the state should invest in cluster sewering of high-density communities, followed by incentivizing septic tank solutions in properties with the highest effluent flow first, then expanding across the area. The total project cost (installation and operation/maintenance) would be $183-258 million, depending upon the sewer-septic combination. An efficiency frontier reveals sub-par combinations, including aerobic treatment units and passive absorption systems, which cost much more and deliver lower mass flux reduction than more cost-effective alternatives. This study contributes a novel case of rural sanitation to the literature in which decision support tools are used to facilitate evidence-based, collaborative decision-making for sanitation planning. The state could use a similar participatory SDM process when approaching other communities to discuss their cesspool upgrade strategies. Broadening the use of decision analytic techniques can have wider ecological, economic, and social benefits for the state and contexts beyond Hawai'i, as SDM provides a transparent and rigorous, evidence-based decision-theoretic framework to explore multiple values and strategies to address difficult resource management problems.

Mismatch between bird species sensitivity and the protection of intact habitats across the Americas.

Protected areas are highly heterogeneous in their effectiveness at buffering human pressure, which may hamper their ability to conserve species highly sensitive to human activities. Here, we use 60 million bird observations from eBird to estimate the sensitivity to human pressure of each bird species breeding in the Americas. Concerningly, we find that ecoregions hosting large proportions of high-sensitivity species, concentrated in tropical biomes, do not have more intact protected habitat. Moreover, 266 high-sensitivity species have little or no intact protected habitat within their distributions. Finally, we show that protected area intactness is decreasing faster where high-sensitivity species concentrate. Our results highlight a major mismatch between species conservation needs and the coverage of intact protected habitats, which likely hampers the long-term effectiveness of protected areas at retaining species. We highlight ecoregions where protection and management of intact habitats, complemented by restoration, is urgently needed.

The mismeasure of conservation.

One of the basic purposes of protected areas and other effective area-based conservation interventions is to achieve conservation impact, the sum of avoided biodiversity loss and promoted recovery relative to outcomes without protection. In the context of the Convention on Biological Diversity's negotiations on the post-2020 Global Biodiversity Framework, we find that targets for area-based interventions are framed overwhelmingly with measures that fail to inform decision-makers about impact and that risk diverting limited resources away from achieving it. We show that predicting impact in space and time is feasible and can provide the basis for global guidance for jurisdictions to develop targets for conservation impact and shift investment priorities to areas where impact can be most effectively achieved.

Decision analysis to support wastewater management in coral reef priority area.

A cocktail of land-based sources of pollution threatens coral reef ecosystems, and addressing these has become a key management and policy challenge in the State of Hawai'i, other US territories, and globally. In West Maui, Hawai'i, nearly one quarter of all living corals were lost between 1995 and 2008. Onsite disposal systems (OSDS) for sewage leak contaminants into drinking water sources and nearshore waters. In recognition of this risk, the Hawai'i State Department of Health (DOH) is prioritizing areas for cesspool upgrades. Independently, we applied a decision analysis process to identify priority areas to address sewage pollution from OSDS in West Maui, with the objective of reducing nearshore coral reef exposure to pollution. The decision science approach is relevant to a broader context of coastal areas both statewide and worldwide which are struggling with identifying pollution mitigation actions on limited budgets.

Understanding local-scale drivers of biodiversity outcomes in terrestrial protected areas.

Conservation relies heavily on protected areas (PAs) maintaining their key biodiversity features to meet global biodiversity conservation goals. However, PAs have had variable success, with many failing to fully maintain their biodiversity features. The current literature concerning what drives variability in PA performance is rapidly expanding but unclear, sometimes contradictory, and spread across multiple disciplines. A clear understanding of the drivers of successful biodiversity conservation in PAs is necessary to make them fully effective. Here, we conduct a comprehensive assessment of the current state of knowledge concerning the drivers of biological outcomes within PAs, focusing on those that can be addressed at local scales. We evaluate evidence in support of potential drivers to identify those that enable more successful outcomes and those that impede success and provide a synthetic review. Interactions are discussed where they are known, and we highlight gaps in understanding. We find that elements of PA design, management, and local and national governance challenges, species and system ecology, and sociopolitical context can all influence outcomes. Adjusting PA management to focus on actions and policies that influence the key drivers identified here could improve global biodiversity outcomes.

Wildlife population trends in protected areas predicted by national socio-economic metrics and body size.

Ensuring that protected areas (PAs) maintain the biodiversity within their boundaries is fundamental in achieving global conservation goals. Despite this objective, wildlife abundance changes in PAs are patchily documented and poorly understood. Here, we use linear mixed effect models to explore correlates of population change in 1,902 populations of birds and mammals from 447 PAs globally. On an average, we find PAs are maintaining populations of monitored birds and mammals within their boundaries. Wildlife population trends are more positive in PAs located in countries with higher development scores, and for larger-bodied species. These results suggest that active management can consistently overcome disadvantages of lower reproductive rates and more severe threats experienced by larger species of birds and mammals. The link between wildlife trends and national development shows that the social and economic conditions supporting PAs are critical for the successful maintenance of their wildlife populations.

International funding agencies: potential leaders of impact evaluation in protected areas?

Globally, protected areas are the most commonly used tools to halt biodiversity loss. Yet, some are failing to adequately conserve the biodiversity they contain. There is an urgent need for knowledge on how to make them function more effectively. Impact evaluation methods provide a set of tools that could yield this knowledge. However, rigorous outcome-focused impact evaluation is not yet used as extensively as it could be in protected area management. We examine the role of international protected area funding agencies in facilitating the use of impact evaluation. These agencies are influential stakeholders as they allocate hundreds of millions of dollars annually to support protected areas, creating a unique opportunity to shape how the conservation funds are spent globally. We identify key barriers to the use of impact evaluation, detail how large funders are uniquely placed to overcome many of these, and highlight the potential benefits if impact evaluation is used more extensively.