Peer-reviewed publications

Background and aim Billfish are epipelagic marine predators facing increasing pressures such as overfishing and rising global temperatures. Overfishing is a major concern, as they are caught by industrial longline fishers targeting tuna. Billfish are targeted by multiple fishing sectors, which provides food, socio-economic and cultural benefits. To support effective billfish management and conservation, it is essential to understand their spatial distribution and the environmental factors that may influence it. Location The focus of this study is the Indian Ocean (IO), where there are gaps in understanding the interactions between fisheries and billfish distribution. Three of six billfish species are at risk from overfishing. Therefore, determining their distribution is crucial to their management and conservation. Methods Using Ocean Biogeographic Information System (OBIS) occurrence data, Indian Ocean Tuna Commission (IOTC) catch data, and environmental covariates, we applied species distribution models to investigate the spatial extent of the realized niches of six billfish species in the IO. We also determined the role and relative importance of environmental drivers. Moreover, we evaluated the association between species’ spatial distribution and the fishing effort distribution. Results We found niche partitioning and overlap among the six species identified spatial distribution, with higher species richness in the northern region of the IO and off the East coast of Africa. Temperature, mixed layer depth and salinity were identified as the most important predictors of species distribution, with moderately warm and stable environments preferred by most billfish species. Areas with high species richness and high fishing effort overlap were primarily found in the Areas Beyond National Jurisdiction (ABNJ). In contrast, areas with high species diversity richness and low fishing effort were found mainly in the Exclusive Economic Zone (EEZ). Main conclusion Spatial overlap between fishing effort and billfish projected distribution suggests inadvertent fishing pressure on billfish populations as they are caught together with targeted tuna. Spatial distribution transcends maritime zones, reinforcing a need to formulate effective management policies for marine areas beyond national jurisdictions.

Conventional flood control has emphasized structural measures such as levees, reservoirs, and engineered channels—measures that typically simplify river channels and cut them off from their floodplain, both with adverse environmental consequences. Structural measures tend to be rigid and not easily adapted to increased flooding regimes resulting from environmental change. Such actions also limit the natural hydrologic benefits of floodplains such as storing floodwaters, improving water quality, providing habitat for invertebrates and fish during periods of inundation, and supporting a multitude of cultural services. As these benefits are more widely recognized, policies are being adopted to encourage projects that reduce flood risks and restore floodplain ecosystems, while acknowledging the social-ecological context. The number of such projects, however, remains small. We assessed four multi-benefit floodplain projects (two in California, United States, and two in Germany) and characterized their drivers, history, and measures implemented. In both United States cases, the dominant driver behind the project was flood risk reduction, and ecosystem restoration followed, in one case inadvertently, in the other as a requirement to receive a subsidy for a flood risk reduction project. One German case was motivated by ecosystem restoration, but it was more widely accepted because it also offered flood management benefits. The fourth case was conceived in terms of balanced goals of flood risk reduction, ecosystem restoration, and recreation. We conclude that projects that both reduce flood risk and restore ecosystems are clearly possible and often cost-effective, and that they could be more widely implemented. The principal barriers are often institutional and regulatory, rather than technical.

Marine Protected Areas (MPAs) often have dual goals of protecting biodiversity and increasing sustainability of fisheries. To understand how MPAs are performing at these goals, evaluation of fish biomass outcomes against management targets is needed. However, the evaluation of performance should consider multiple biophysical and social drivers that vary over the seascape to inform spatially explicit targets for fish biomass. Including spatial variation when evaluating MPA performance is particularly important for MPA networks because it enables managers to set more realistic expectations for MPA outcomes and adapt management across individual areas. Here we develop a modelling approach to predict how fishing pressure and biophysical conditions affect expected recovery of fish biomass. We apply the approach to model herbivore and predator biomass at 57 sites for two MPAs in Raja Ampat, Indonesia. We then use this model to predict biomass recovery towards reference sites indicative of low-fishing pressure. We found that historical fishing pressure, wave exposure and proximity to coastal habitats were all important determinants of pre-MPA fish biomass. Our predictions therefore, indicated the implemented MPA no-take zones should have some of the highest reef fish biomass based on both their location within the MPA, and the removal of fishing pressure. We also identify sites that may be underperforming and warrant further management, for instance, further investigation of poaching as a cause of poor recovery trends. We suggest that evaluation of MPA performance needs to consider the link to historical fishing pressure and biophysical conditions with biodiversity outcomes.

Climate change is predicted to drive various changes in hydrology that can translate into 10 risks for river ecosystems and for those who manage rivers, such as for hydropower. Here we use 11 the WWF Water Risk Filter (WRF) and geospatial analysis to screen hydropower projects, both ex-12 isting (2,488 dams) and projected (3,700 dams), for a variety of risks at a global scale, focusing on 13 biodiversity risks, hydrological risks (water scarcity and flooding), and how those hydrological risks 14 may shift with climate change, based on three scenarios. Approximately 26% of existing hydro-15 power dams and 23% of projected dams are within river basins that currently have medium to very 16 high risk of water scarcity; 32% and 20% of the existing and projected dams, respectively, are pro-17 jected to have increased risk by 2050 due to climate change. For flood risk, 75% of existing dams and 18 83% of projected dams are within river basins with medium to very high risk, and the proportion of 19 hydropower dams in basins with the highest levels of flood risk are projected to increase by nearly 20 twenty times (e.g., from 2% to 36% of dams). In addition, a large proportion of existing (76%) and 21 projected hydropower dams (93%) are located in river basins with high or very high freshwater 22 biodiversity importance. This is a high-level screening, intended to elucidate broad patterns of risk 23 to increase awareness, highlight trends, and guide more detailed study.

Marine protected areas (MPAs) are considered the go-to tool for marine area-based conservation, having rapidly expanded in many countries, yet an understanding of progress and achievement in implementation remains vastly unexplored. Here, we assess the status and trends of coverage and protection, ecological conditions, marine resource use, human well-being, and management effectiveness of MPAs in the Sunda Banda Seascape (SBS), Indonesia, and provide the first comprehensive overview of marine conservation in the region. The SBS, located in the world's epicenter for marine biodiversity, has 85 designated MPAs (8.1 million ha) as of 2018, accounting for 35% of the national target of 23.4 million ha MPAs by 2020. Most SBS MPAs were recently initiated or established, and their management was strongly influenced by policy and governance changes at the national and provincial levels. SBS MPAs protect more than 30% of mangrove, seagrass, and coral reefhabitats in the seascape, and surveys indicate relatively healthy coral reef conditions. Fishing is one of the most common livelihoods in the MPA communities; 90% of fishers use traditional gear types for fishing and destructive fishing is identified as the greatest threat to marine resources in the MPAs. Our findings suggest that balancing the expansion of MPAs with strengthening their management effectiveness and integrating diverse social-ecological local contexts are important aspects to achieve effective, equitable marine conservation.

Progress in key social-ecological challenges of the global environmental agenda (e.g., climate change, biodiversity conservation, Sustainable Development Goals) is hampered by a lack of integration and synthesis of existing scientific evidence. Facing a fast-increasing volume of data, information remains compartmentalized to pre-defined scales and fields, rarely building its way up to collective knowledge. Today's distributed corpus of human intelligence, including the scientific publication system, cannot be exploited with the efficiency needed to meet current evidence synthesis challenges; computer-based intelligence could assist this task. Artificial Intelligence (AI)-based approaches underlain by semantics and machine reasoning offer a constructive way forward, but depend on greater understanding of these technologies by the science and policy communities and coordination of their use. By labelling web-based scientific information to become readable by both humans and computers, machines can search, organize, reuse, combine and synthesize information quickly and in novel ways. Modern open science infrastructure—i.e., public data and model repositories—is a useful starting point, but without shared semantics and common standards for machine actionable data and models, our collective ability to build, grow, and share a collective knowledge base will remain limited. The application of semantic and machine reasoning technologies by a broad community of scientists and decision makers will favour open synthesis to contribute and reuse knowledge and apply it toward decision making.

To more effectively protect biodiversity and promote sustainable development, transfrontier conservation areas (TFCAs) aim to enhance wildlife flows across national borders. This is true of the world's largest terrestrial TFCA, the Kavango-Zambezi (KAZA), home to half of Africa's savannah elephants that move across five countries in a mixed-use landscape. We used GPS tracking data from >100 collared elephants to evaluate how fences between Namibia and Botswana impact transboundary connectivity in KAZA. For female elephants these fences formed an impenetrable boundary, with no exchange between animals collared in Botswana and those collared in Namibia. Male elephants did cross border fences, although they remained a partial boundary, with 7 of 21 males accounting for most crossings. Our results suggest a review of fence alignment and de-commissioning of some fencing separating Namibia and Botswana, combined with increased support for fence-free interventions that reduce wildlife-livestock interactions, should be considered to meet the objectives of KAZA.

Freshwater biodiversity is declining dramatically, and the current biodiversity crisis requires defining bold goals and mobilizing substantial resources to meet the challenges. While the reasons are varied, both research and conservation of freshwater biodiversity lag far behind efforts in the terrestrial and marine realms. We identify fifteen pressing global needs to support informed global freshwater biodiversity stewardship. The proposed agenda aims to advance freshwater biodiversity research globally as a critical step in improving coordinated action towards its sustainable management and conservation.

Future climate projections of warming, drying, and increased weather variability indicate that conventional agricultural and production practices within the Northern Great Plains (NGP) will become less sustainable, both ecologically and economically. As a result, the livelihoods of people that rely on these lands will be adversely impacted. This is especially true for Native American communities, who were relegated to reservations where the land is often vast but marginal and non-tribal operators have an outsized role in food production. In addition, NGP lands are expected to warm and dry disproportionately relative to the rest of the United States. It is therefore critical to identify models of sustainable land management that can improve ecological function and socio-economic outcomes for NGP communities, all while increasing resilience to a rapidly changing climate. Efforts led by Native American Nations to restore North American Plains bison (Bison bison bison) to tribal lands can bring desired socio-ecological benefits to underserved communities while improving their capacity to influence the health of their lands, their people, and their livelihoods. Ecological sustainability will depend on the restoration of bison herds and bison’s ability to serve as ecosystem engineers of North America’s Plains. The historically broad distribution of bison suggests they can adapt to a variety of conditions, making them resilient to a wide range of management systems and climates. Here we review bison’s ecological, cultural, and economic value using four case studies from tribal communities within the NGP. We discuss the potential contributions of bison to food sovereignty, sustainable economies, and conservation of a working landscape with limited protections and significant risk of conversion. The ecological role of bison within this setting has potential due to cultural acceptance and the vast availability of suitable lands; however, it is critical to address tribal needs for funding support, enhanced community capacity, and solving complex landownership for these goals to be achieved.

Attempts to mitigate the biodiversity crisis require effective indicators on the state of nature, and the Living Planet Index1 (LPI) is an important tool for policy response and for communicating the importance of biodiversity declines to the general public. We welcome the recent analysis of Leung et al.2, who identified clusters in population trends between 1970 and the present from the LPI and illustrated that previously reported vertebrate declines are sensitive to a small percentage of declining populations. We agree that the disaggregation of indices such as the LPI can provide many useful insights1, but caution against the over-interpretation of stable or even increasing recent population trends as success stories, because for many vertebrate species, critical losses to populations happened before 1970 (the start date of the LPI). Shifting baselines for conservation success stories need to be confronted if we are to set biodiversity targets that meaningfully represent humans living in harmony with nature for the Post-2020 Biodiversity Framework.