Peer-reviewed publications

The ocean is our planet’s largest life-support system. It stabilizes climate; stores carbon; produces oxygen; nurtures biodiversity; directly supports human well-being through food, mineral, and energy resources; and provides cultural and recreational services. The value of the ocean economy speaks to its importance: The Organization for Economic Cooperation and Development (OECD) estimates that by 2030, $3 trillion USD will be generated annually from ocean sectors such as transportation, fishing, tourism, and energy (1). Unsustainable resource extraction, pollution, climate change, and habitat destruction are on the rise and affecting many parts of the world’s oceans (2). The ocean is rapidly changing, and yet the ways in which these changes will play out are not yet clear.

Facing public concern over costs related to top-predator reintroductions and conservation, ecosystem services such as ecotourism are often used to evoke benefits that outweigh or offset those costs. Quantifying these benefits using rigorous scientific methods can provide confidence to policymakers and other stakeholders that predators can in fact deliver positive outcomes to people living alongside them. The evaluation of these benefits is often anecdotal or qualitative, however, and empirical quantifications are rare.

Concern for megafauna is increasing among scientists and non-scientists. Many studies have emphasized that megafauna play prominent ecological roles and provide important ecosystem services to humanity. But, what precisely are 'megafauna'? Here, we critically assess the concept of megafauna and propose a goal-oriented framework for megafaunal research. First, we review definitions of megafauna and analyse associated terminology in the scientific literature. Second, we conduct a survey among ecologists and palaeontologists to assess the species traits used to identify and define megafauna. Our review indicates that definitions are highly dependent on the study ecosystem and research question, and primarily rely on ad hoc size-related criteria. Our survey suggests that body size is crucial, but not necessarily sufficient, for addressing the different applications of the term megafauna. Thus, after discussing the pros and cons of existing definitions, we propose an additional approach by defining two function-oriented megafaunal concepts: 'keystone megafauna' and 'functional megafauna', with its variant 'apex megafauna'. Assessing megafauna from a functional perspective could challenge the perception that there may not be a unifying definition of megafauna that can be applied to all eco-evolutionary narratives. In addition, using functional definitions of megafauna could be especially conducive to cross-disciplinary understanding and cooperation, improvement of conservation policy and practice, and strengthening of public perception. As megafaunal research advances, we encourage scientists to unambiguously define how they use the term 'megafauna' and to present the logic underpinning their definition.

Despite their limited spatial extent, freshwater ecosystems host remarkable biodiversity, including one-third of all vertebrate species. This biodiversity is declining dramatically: Globally, wetlands are vanishing three times faster than forests, and freshwater vertebrate populations have fallen more than twice as steeply as terrestrial or marine populations. Threats to freshwater biodiversity are well documented but coordinated action to reverse the decline is lacking. We present an Emergency Recovery Plan to bend the curve of freshwater biodiversity loss. Priority actions include accelerating implementation of environmental flows; improving water quality; protecting and restoring critical habitats; managing the exploitation of freshwater ecosystem resources, especially species and riverine aggregates; preventing and controlling nonnative species invasions; and safeguarding and restoring river connectivity. We recommend adjustments to targets and indicators for the Convention on Biological Diversity and the Sustainable Development Goals and roles for national and international state and nonstate actors.

Coral reef fisheries depend on reef fish biomass to support ecosystem functioning and sustainable fisheries. Here, we evaluated coral reefs across 4,000 km of the Indonesian archipelago to reveal a large gradient of biomass, from <100 kg/ha to >17,000 kg/ha. Trophic pyramids characterized by planktivore dominance emerged at high biomass, suggesting the importance of pelagic pathways for reef productivity. Total biomass and the biomass of most trophic groups were higher within gear restricted and no‐take management, but the greatest biomass was found on unmanaged remote reefs. Within marine protected areas (MPAs), 41.6% and 43.6% of gear restricted and no‐take zones, respectively, met a global biomass target of 500 kg/ha, compared with 71.8% of remote sites. To improve conservation outcomes for Indonesia's biodiverse and economically important coral reef fisheries, our results suggest to: (1) strengthen management within Indonesia's existing MPAs and (2) precautionarily manage remote reefs with high biomass.

The health of coastal human communities and marine ecosystems are at risk from a host of anthropogenic stressors, in particular, climate change. Because ecological health and human well-being are inextricably connected, effective and positive responses to current risks require multidisciplinary solutions. Yet, the complexity of coupled social–ecological systems has left many potential solutions unidentified or insufficiently explored. The urgent need to achieve positive social and ecological outcomes across local and global scales necessitates rapid and targeted multidisciplinary research to identify solutions that have the greatest chance of promoting benefits for both people and nature. To address these challenges, we conducted a forecasting exercise with a diverse, multidisciplinary team to identify priority research questions needed to promote sustainable and just marine social–ecological systems now and into the future, within the context of climate change and population growth. In contrast to the traditional reactive cycle of science and management, we aimed to generate questions that focus on what we need to know, before we need to know it. Participants were presented with the question, "If we were managing oceans in 2050 and looking back, what research, primary or synthetic, would wish we had invested in today?" We first identified major social and ecological events over the past 60 years that shaped current human relationships with coasts and oceans. We then used a modified Delphi approach to identify nine priority research areas and 46 questions focused on increasing sustainability and well-being in marine social–ecological systems. The research areas we identified include relationships between ecological and human health, access to resources, equity, governance, economics, resilience, and technology. Most questions require increased collaboration across traditionally distinct disciplines and sectors for successful study and implementation. By identifying these questions, we hope to facilitate the discourse, research, and policies needed to rapidly promote healthy marine ecosystems and the human communities that depend upon them.

Collisions between ships and whales raise environmental, safety, and economic concerns. The management of whale-ship collisions, however, lacks a holistic approach, unlike the management of other types of wildlife-vehicle collisions, which have been more standardized for several years now. In particular, safety and economic factors are routinely omitted in the assessment of proposed mitigation solutions to ship strikes, possibly leading to under-compliance and a lack of acceptance from the stakeholders. In this study, we estimate the probability of ship damage due to a whale-ship collision. While the probability of damage is low, the costs could be important, suggesting that property damages are significant enough to be taken into consideration when assessing solutions. Lessons learned from other types of wildlife-vehicle collisions suggest that the whale-ship collision should be managed as wildlife-aircraft collisions. For several years, the International Civil Aviation Organization (ICAO) manages collisions between aircrafts and wildlife at the international level. We advocate that its United Nations counterpart, namely the International Maritime Organization (IMO), get more involved in the whale-ship collision management. Further research is needed to more precisely quantify the costs incurred to ships from damages caused by whale-ship collisions.

Does oil palm boost agricultural growth and reduce rural poverty, or is it a threat to rural livelihoods and tropical forest landscapes? This paper introduces a Special Issue on this question, focusing on Latin America. It reviews available literature and data for countries where oil palm either covers large areas (Brazil, Colombia, Ecuador, Honduras) or has recently expanded (Costa Rica, Guatemala, Mexico, Peru), and presents evidence from nine case studies (including Nicaragua). Combining political economy with a livelihood approach, this article discusses how dissimilar policies supporting oil palm combined with contrasting agrarian change dynamics, market structures, and institutional arrangements driving rural inclusion (and exclusion) in oil palm production have resulted in a variety of expansion trajectories (ranging from smallholder-to plantation-based, plus mixed forms in between) and outcomes across the region. Main findings show that rural livelihoods and landscapes are most threatened where industrial plantations predominate, particularly in weakly governed forest frontiers, while oil palm is beneficial where policies guarantee land access and support smallholders. However, policies that are beneficial to smallholders do not preclude conflicts between oil palm smallholders (often migrant settlers) and forest-dependent (indigenous and Afro-descendant) communities opposing this industry.

Palm oil makes a significant contribution to the economies of Indonesia and Malaysia through private corporations, state-owned companies and smallholders, with the two countries supplying 85% of the global palm oil. Indonesia has 14 million hectares (ha) of oil palm; its palm oil exports were valued at USD 23 billion in 2017 and USD 21 billion in 2018. Both domestic and international communities, particularly the European Union (EU), have raised concerns about its sustainability and impact on forest conservation. For example, the European Parliament in 2017 issued a resolution to restrict the ability of EU countries to count palm oil-based biodiesel imports toward their renewable 2030 energy targets. This paper describes palm oil value chains in Indonesia at the national level, using value chain analysis and system dynamics modeling. The model is used to understand how the moratorium, peatland conservation, agrarian reform, and the EU biodiesel ban affect plantation expansion and production, employment, CO2 emissions, smallholder incomes, the private sector, and government. The model provides scenarios to make Indonesian palm oil more sustainable through intensification, no-deforestation, and no-peat strategies, as well as through land swapping. There are trade-offs between economic development and environmental conservation, but win-win solutions are available. Scenarios that build synergies between Indonesian palm oil development and forest conservation can help guide the new frontiers of oil palm development in Asia, South America, and Africa.

The paper assesses the effects of public innovation initiated by demands from communities in the northern Bolivian Amazon to revise forest regulations and policies. Bolivia enacted wide-reaching land and forest reforms in the mid-1990s, but these reforms were insufficient to tackle competing claims on forests and exclusion of local forest users from benefiting from timber production. Pressures by forest communities resulted in significant adjustments in regulations and policies, and the main driver was social pressure from communities as well as their representatives. The adjustments have allowed communal local practices, which were previously illegal, to become legal. They have allowed communities access to timber markets, improve incomes, and enhanced compliance with timber regulations.