Peer-reviewed publications

Increasingly frequent severe coral bleaching is among the greatest threats to coral reefs posed by climate change. Global climate models (GCMs) project great spatial variation in the timing of annual severe bleaching (ASB) conditions; a point at which reefs are certain to change and recovery will be limited. However, previous model-resolution projections (~1?×?1°) are too coarse to inform conservation planning. To meet the need for higher-resolution projections, we generated statistically downscaled projections (4-km resolution) for all coral reefs; these projections reveal high local-scale variation in ASB. Timing of ASB varies >10 years in 71 of the 87 countries and territories with >500?km2 of reef area. Emissions scenario RCP4.5 represents lower emissions mid-century than will eventuate if pledges made following the 2015 Paris Climate Change Conference (COP21) become reality. These pledges do little to provide reefs with more time to adapt and acclimate prior to severe bleaching conditions occurring annually. RCP4.5 adds 11 years to the global average ASB timing when compared to RCP8.5; however, >75% of reefs still experience ASB before 2070 under RCP4.5. Coral reef futures clearly vary greatly among and within countries, indicating the projections warrant consideration in most reef areas during conservation and management planning.

Resource use was investigated at 34 Litopenaeus vannamei and five Penaeus monodon farms in Thailand and 30 L. vannamei and 24 P. monodon farms in Vietnam. Farms varied in water surface areas for production, reservoirs, canals, and settling basins; in pond size and depth; and in water management, stocking density, feeding rate, amendment input, aeration rate, crop duration, and crops per year. Production of L. vannamei averaged 17.3 and 10.9?m.t./ha/yr, and feed conversion ratio averaged 1.49 and 1.33 in Thailand and Vietnam, respectively. On average, production of 1?m.t. of L. vannamei required 0.58?ha land, 5,400?m3 water, 60?GJ energy, and 1218?kg wildfish in Thailand and 1.76?ha land, 15,100?m3 water, 33.7?GJ energy, and 1264?kg wildfish in Vietnam. Resource use per metric ton of shrimp declined with greater production intensity. In Thailand, P. monodon was produced at 0.2–0.4?m.t./ha/yr, with no inputs but water and postlarvae. In Vietnam, P. monodon production averaged 3.60?m.t./ha/yr. Production of 1?m.t. of P. monodon required 0.80?ha land, 36,000?m3 water, 47.8?GJ energy, and 1180?kg wildfish, and resource use per ton production declined with increasing production intensity.

The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.

The US Endangered Species Act (ESA) regulates what landowners, land managers, and industry can do on lands occupied by listed species. The ESA does this in part by requiring the designation of habitat within each listed species’ range considered critical to their recovery. Critics have argued that critical habitat (CH) designation creates significant economic costs while contributing little to species recovery. Here we examine the effects of CH designation on land cover change. We find that the rate of change from 1992 to 2011 in developed (urban and residential) and agricultural land in CH areas was not significantly different compared to similar lands without CH designation, but still subject to ESA regulations. Although CH designation on average does not affect overall rates of land cover change, CH designation did slightly modify the impact of land cover change drivers. Generally, variation in land prices played a larger role in land cover decisions within CH areas than in similar areas without CH designation. These trends suggest that developers may require a greater than typical expected return to development in CH areas to compensate for the higher risk of regulatory scrutiny. Ultimately, our results bring into question the very rationale for the CH regulation. If it is for the most part not affecting land cover choices, is CH helping species recover?

An abstract is not available for this content.

Recent surveys suggest tens of thousands of elephants are being poached annually across Africa, putting the two species at risk across much of their range. Although the financial motivations for ivory poaching are clear, the economic benefits of elephant conservation are poorly understood. We use Bayesian statistical modelling of tourist visits to protected areas, to quantify the lost economic benefits that poached elephants would have delivered to African countries via tourism. Our results show these figures are substantial (~USD $25 million annually), and that the lost benefits exceed the anti-poaching costs necessary to stop elephant declines across the continent’s savannah areas, although not currently in the forests of central Africa. Furthermore, elephant conservation in savannah protected areas has net positive economic returns comparable to investments in sectors such as education and infrastructure. Even from a tourism perspective alone, increased elephant conservation is therefore a wise investment by governments in these regions.

Policies aimed at reducing deforestation in the Amazon basin, such as ARPA and a robustly enforced Forest Code, could have a substantial influence on the basin’s future hydropower production potential, land-use based carbon emissions, and gross economic product. We use regional models to estimate the impact that high levels of forest conservation will have on the Basin’s provision of these ecosystem services and its overall economic performance as of 2050 relative to the Basin’s delivery of these services and economic performance from a much more developed 2050 landscape. We identify three major lessons learned from our research. First, the hydropower benefits of forest conservation policies, including protected areas, are distributed unevenly across the Amazon basin due to atmospheric feedbacks. Second, these policies also have a substantial influence on regional and global carbon emissions. Finally, policymakers need to be cognizant of the substantial economic opportunity costs that conservation policies can create and how the spatial mismatch of policy costs and benefits can lead to policy failure. For example, we find that the loss in basin gross product in 2050 due to more stringent forest conservation is likely to be greater than combined value of more hydropower potential and more carbon sequestration in 2050 due to more stringent forest conservation. For Brazilians specifically the calculus is even a bit worse as carbon sequestration is a global good that accrues to most people outside of Brazil. Of course our analysis is missing the many other valuable ecosystem services than are enhanced by conservation. We would need to add these additional ecosystem service values to our cost-benefit ledger before we could begin to ascribe the full conservation-economic tradeoffs to more stringent forest conservation.

Delivering access to sufficient food, energy and water resources to ensure human wellbeing is a major concern for governments worldwide. However, it is crucial to account for the ‘nexus’ of interactions between these natural resources and the consequent implications for human wellbeing. The private sector has a critical role in driving positive change towards more sustainable nexus management and could reap considerable benefits from collaboration with researchers to devise solutions to some of the foremost sustainability challenges of today. Yet opportunities are missed because the private sector is rarely involved in the formulation of deliverable research priorities. We convened senior research scientists and influential business leaders to collaboratively identify the top forty questions that, if answered, would best help companies understand and manage their food-energy-water-environment nexus dependencies and impacts. Codification of the top order nexus themes highlighted research priorities around development of pragmatic yet credible tools that allow businesses to incorporate nexus interactions into their decision-making; demonstration of the business case for more sustainable nexus management; identification of the most effective levers for behaviour change; and understanding incentives or circumstances that allow individuals and businesses to take a leadership stance. Greater investment in the complex but productive relations between the private sector and research community will create deeper and more meaningful collaboration and cooperation.

The Nile crocodile, Crocodylus niloticus, is found throughout sub-Saharan Africa, including Namibia, Botswana and Angola. The species was transferred from CITES Appendix I to Appendix II in 2004, although it is recognized as peripherally endangered in Namibia due to diminishing habitat availability primarily from human encroachment. In 2013, a species management plan was approved in Namibia to assess the management of the Namibian Nile crocodile populations. During 2012, an aerial survey was conducted to provide an estimate of Nile crocodile population numbers. A recently developed N-mixture model for estimation of abundance and spatial variation was used. Detection probability correlated to animal size and environmental covariates. Our data also suggest that small crocodiles are easier to detect during the spring. The abundance for different size classes was influenced by river complexity (vegetation, depth, channels) and the distribution of human settlements. An estimated 806 individuals were counted along the 352 km Namibian portion of the Kunene River system with a conservative estimate of 562 crocodiles regardless of size. The parameter estimates generated by the analysis suggested that the class-structured model can produce reliable estimates of total abundance and of local abundance for this section in the Kunene River system.

table {mso-displayed-decimal-separator:"\."; mso-displayed-thousand-separator:"\,";} tr Marine protected areas (MPAs) have historically been implemented and managed in a top-down way, excluding resource-dependent users from planning and management. In response to conflict and non-compliance, the governance of marine resources is increasingly embracing community-based approaches, assuming that by putting communities at the forefront of planning and management, participation will increase, causing positive social and ecological impacts. Given the relative newness of community-based MPAs, this study explores how resource users perceive their impacts on ecosystem services (ES) and human well-being (HWB). This study explores two community-based MPAs called tengefus in Kenya using mixed qualitative methods, including a participatory photography method called photovoice. Participation in and donor support for tengefus influences how resource users perceived tengefus and their impacts on ES and HWB. Individuals who were engaged in the tengefu from the inception or held official positions perceived more positive impacts on ES and HWB compared to those not as involved. Tengefus were often viewed by communities as attractors for external support and funding, positively influencing attitudes and feelings towards conservation. One site, the first tengefu in Kenya, had more external support and was surrounded by positive perceptions, while the other site had little external support and was surrounded by more conflict and mixed perceptions. This study exemplifies the complex social-political dynamics that MPAs create and are embedded within. Community-based MPA initiatives could benefit from ensuring widespread engagement throughout the inception, implementation and management, recognizing and managing expectations around donor support, and not assuming that benefits spillover throughout the community.