Peer-reviewed publications

Users of marine recreational and artisanal fisheries share a great interest in common resources, driving potential competitive interactions. In the Western Indian Ocean (WIO), limited information exists about these fisheries in particular for billfish species. The importance of billfish as a highly sought-after game fish species in recreational fishing, a source of food and income for artisanal fishers, and their ability to transverse various national jurisdictions as a shared resource make it necessary to evaluate sectoral interactions. Herein, we ask the question: what is the nature of these interactions in Kenyan waters? We developed criteria for inferring competitive interactions based on time, space, and resource use and using billfish landings data collected through the creel survey, fishery-dependent sampling, and tagging. Results from tag recaptures show that both fishing sectors are capturing the same billfish resource, with a dominance of sailfish landings. We found no significant difference in the average landings between artisanal and recreational sectors, indicating equal demand for the billfish resource in terms of target species, geographic distribution, and seasonality. Therefore, our results suggest competitive interactions between the recreational and artisanal sectors, which have significant implications for management and socio-economic benefits for coastal communities.

In the Western Indian Ocean (WIO) region, information and data on marine recreational fisheries (MRF) is lacking, which undermines efforts towards their sustainable development. Our paper reviews the challenges and opportunities for sustainably developing marine recreational fisheries in the WIO. We identified several challenges that are discussed in two broad categories: (i) governance and (ii) socio-cultural and economic. We also show that addressing these challenges requires a holistic understanding of the socio-ecological complexities and the multi-scale nature of WIO MRF. Realizing the potential for sustainable development of this sector calls for the involvement of coastal communities in the sharing of benefits and decision-making. Further, coordinated efforts between the multi-government agencies and non-governmental organizations is critical for integrating recreational fisheries into local and national agendas. We conclude that the sustainable development of MRF in the WIO region is possible. Still, such growth will be dependent upon the sustained capacity building of coastal communities and indigenous fishers, collaboration from stakeholders, and the long-term sustainability of the resource.

Due to its controversies, oil palm cultivation has been targeted by regulatory innovations. Among these, transnational efforts—such as the Roundtable on Sustainable Palm Oil (RSPO) and corporate commitments to zero deforestation have been highly influential but often tend to overvalue environmental over socio-economic outcomes. This article discusses to what extent domestic governance models of palm oil producing countries can be better equipped to reconcile domestic demands such as economic development and poverty alleviation, and transnational concerns about forest conservation. We do so by looking into the Brazilian case, where the government intended to drive oil palm expansion in the Amazon through a program launched in 2010 that simultaneously only allowed expansion into already deforested areas and offered companies incentives to engage smallholder farmers in their supply chains. Our findings, drawn from primary research activities and existing literature, indicate that Brazil has managed to avoid deforestation typically associated with oil palm expansion elsewhere. Oil palm establishment involved the conversion of 0.8% and 1.3% of primary forests for corporate and smallholder plantations, respectively. However, the Brazilian government did not manage to optimally enhance smallholder participation in the sector, as significant differences in performance were observed between farmers, ranging from very successful (17%) to highly unsuccessful (12%); and failed to achieve sectoral development and competitiveness targets. While some failings can be attributed to external factors such as context, broader domestic governance frameworks and alignments, and private supply chain initiatives, the program itself did not manage to reconcile social, environmental and economic objectives into a single coherent sectoral governance model. Yet, this case study suggests that domestic governance strategies can enable commodity production in a way that is more coherent with national priorities, at the same time as preventing deforestation and minimizing social risks more effectively.

The water-energy-food nexus concept is criticized as not yet fit for deeply integrated and contested governance agendas. One problem is how to achieve equitable risk governance and management where there is low consensus on priorities, poor inclusion and coordination of risk assessment procedures, and a weak emphasis placed on cross-scale and sectoral interactions over time. Participatory system dynamics modeling processes and analyses are promising approaches for such challenges but are currently underutilized in nexus research and policy. This paper shares our experience implementing one such analysis in the Mekong river basin, a paradigmatic example for international nexus research. Our transdisciplinary research design combined participatory causal loop diagramming processes, scenario modeling, and a new resilience analysis method to identify and test anticipated water-energy-food risks in Kratie and Stung Treng provinces in northeastern Cambodia. Our process generated new understanding of potential cross-sectoral and cross-level risks from major hydropower development in the region. The results showed expected trade-offs between national level infrastructure programs and local level food security, but also some new insights into the effects local population increases may have on local food production and consumption even before hydropower developments are built. The analysis shows the benefit of evaluating risks in the nexus at different system levels and over time because of how system dynamics and inflection points are taken into account. Additionally, our case illustrates the contribution participatory system-thinking processes can make to risk assessment procedures for complex systems transitions. We originally anticipated that any new capacity reported by partners and participants would come from our modeling results produced at the end of the process. However, participants in the modeling procedures also found the experience powerful the information sharing, rapid risk assessment, and personal learning it enabled. A lesson from our experience reinforces a message from the transdisciplinary research field that has not yet been absorbed into the nexus research and policy field wholeheartedly: we do not have to wait for perfect data and incontestable results before making a positive contribution to anticipating and responding to risks that emerge from nexus relations if we apply participatory and systems-thinking informed approaches.

Despite our improved understanding of the importance of mangrove forests and their ecosystem services, negative perceptions of these wetlands are still common. We highlight the dangers of recurrent public misperceptions about mangroves and how they can be countered. The authors represent a variety of stakeholders involved in the research and communication of mangrove forests through academia, government agencies and non-governmental organizations involved in conservation.

Habitat restoration will prove critical if we are to reverse current population declines and extinction rates of Threatened species. This is particularly the case for forest restoration, given that >80% of Threatened species live in forests and they are habitat for 80% of amphibians, 75% of birds, 68% of mammals and approximately 60% of all tropical vascular plants. While the UN General Assembly has declared 2021 to 2030 as the Decade of Ecosystem Restoration and the Bonn Challenge aims to place at least 350 million hectares of degraded landscapes under restoration, to date there remains little guidance on where to target restoration efforts to support Threatened species. We conduct a global analysis of terrestrial vertebrate species listed as Threatened and Near Threatened in the IUCN Red List of Threatened Species that occur in forests and have Habitat and Natural Processes Restoration as a recommended conservation action. The analysis identifies critical restoration regions that host Threatened species whose recovery could benefit from effective forest or landscape restoration strategies. With habitat restoration as an important solution to reversing declining population trends and extinctions of Threatened forest species, identification of these critical landscapes should help guide future forest restoration efforts towards locations where they may benefit the maximum number of Threatened species.

Estimates of aeration energy use in shrimp farming varied from 11.4 to 41.6 GJ/t shrimp (average = 19.8 GJ/t). Several opportunities for reducing energy use in aeration are available. Many farms adopt an excessive yield to installed aeration capacity ratio. Moreover, the proportion of installed aerator capacity in use and duration of aerator operation per day are often more than necessary during the initial two‐thirds of grow‐out, because adjustment is not made for the quantity of shrimp biomass. Farm‐made, long‐arm aerators used in Asia have several features leading to energy inefficiency and could be replaced by more efficient factory‐made, long‐arm aerators. Asian aquaculture aerator manufacturers should redesign aerators to include design features shown in research to improve efficiency. Dissolved oxygen concentration monitoring essential for verification of aeration performance is seldom performed by shrimp farmers. With good aeration technique, energy use for aeration should not exceed 10–15 GJ/t shrimp.

Mesophotic coral ecosystems (MCEs; reefs 30–150 m depth) are poorly studied, with existing research heavily geographically biased away from the most species-rich reef regions. Yet, MCEs are of high interest because of their unique species and potential to act as refuges from the impacts of fishing. Using baited remote underwater video systems, we surveyed reef fish communities from 2 to 85 m depths throughout the Raja Ampat archipelago in West Papua, Indonesia—an area considered the heart of the Coral Triangle where coral reef biodiversity is greatest. We sought to provide the first assessment of fish communities across this depth gradient in the region and identify whether human population density and market access differently affected fish abundance based on depth. Here we show that—similar to shallow reefs—Raja Ampat MCEs are exceptionally diverse, with 152 fish species recorded at depths greater than 40 m. We found that fish community structures were highly depth driven, with declines in fish abundance at increased depth. In contrast to previous studies elsewhere in the world, we found that the proportion of planktivores declined across the shallow reef to MCE depth gradient. While greater human population density correlated with lower Epinephelidae and Lutjanidae abundance (two key fisheries families), we did not find evidence that MCEs provide a depth refuge from fishing. Surprisingly, we also found that fish abundance declined at greater distances from the major regional market—likely caused by historical fisheries pressure in more remote areas. These results both expand upon and contrast some previously established MCE-depth patterns and human impact patterns on fish communities, suggesting that regional context and historical pressures matters. Our findings highlight the need for future MCE studies within the Coral Triangle region

Contrary to most terrestrial organisms, which release their carbon into the atmosphere after death, carcasses of large marine fish sink and sequester carbon in the deep ocean. Yet, fisheries have extracted a massive amount of this “blue carbon,” contributing to additional atmospheric CO2 emissions. Here, we used historical catches and fuel consumption to show that ocean fisheries have released a minimum of 0.73 billion metric tons of CO2 (GtCO2) in the atmosphere since 1950. Globally, 43.5% of the blue carbon extracted by fisheries in the high seas comes from areas that would be economically unprofitable without subsidies. Limiting blue carbon extraction by fisheries, particularly on unprofitable areas, would reduce CO2 emissions by burning less fuel and reactivating a natural carbon pump through the rebuilding of fish stocks and the increase of carcasses deadfall.

Various proposals for the new CBD outcome goals have focused on individual facets of nature, such as ecosystems, species, or genetic diversity. What has been missing is a unified view on how these facets relate to each other in setting goals to achieve the CBD's 2050 vision. To address this gap, we surveyed, evaluated, and discussed published proposals of goals for ecosystems, species, genetic diversity, and nature's contributions to people (NCP) in relation to the empirical and theoretical knowledge in the scientific literature. Our evaluation addresses whether proposed goals encompass, are consistent with, or are opposed to each other; whether they are sufficiently ambitious such that meeting them will indeed curb and reverse biodiversity trends; and whether they contain all the elements needed to make them difficult to “game” (i.e., avoid making substantial contributions by exploiting weaknesses in wording) (see SM for details on our analysis).