Escaping the perfect storm of simultaneous climate change impacts on agriculture and marine fisheries

The availability and production of food is threatened by climate change, with subsequent implications for food security and the global economy. In this study we assessed how the impacts of climate change on agriculture and marine fisheries interact under a range of scenarios. The 'business-as-usual' scenario would lead to ~90% of the global population, particularly in least developed countries, being exposed to declines in the productivity of both sectors, and < 3% of the world would experience productivity gains in both sectors. With strong mitigation equivalent to meeting Paris Agreement commitments, most countries including both the most vulnerable and the largest carbon emitters would show net gains in both agricultural and fisheries sectors

Culture informationnelle et didactique de l\u27information

Le GRCDI (Groupe de Recherche sur la Culture et la Didactique de l\u27Information) est un groupe de recherche créé en 2007 à l\u27initiative de l\u27URFIST de Rennes et rattaché à l\u27ERTé «Culture informationnelle et curriculum documentaire », dont il constitue le prolongement pour les régions de l\u27Ouest. Ce rapport de synthèse, élaboré en lien avec le rapport final de l\u27ERTé, est fondé sur l\u27ensemble des publications du groupe depuis 2007 et vise à faire un état des lieux de la réflexion du groupe sur la culture informationnelle et la didactique de l\u27information. Il est structuré autour de trois grandes entrées : l\u27émergence, les approches, les questions. La première partie cherche à analyser et retracer le double phénomène d\u27émergence et de développement de la culture informationnelle et de la didactique info-documentaire. La deuxième partie tente de rendre compte de la diversité, de la multiplicité des approches, des conceptions et des facettes de la culture et de la didactique de l\u27information. Enfin la troisième partie porte sur les questions en débat, les problèmes, les obstacles, les chantiers ouverts dans chacun des deux domaines. A ces trois entrées transversales s\u27ajoute une quatrième, centrée sur la question du curriculum info-documentaire et faisant état des remarques et des préconisations du GRCDI. Il ne s\u27agit pas ici de fournir un curriculum info-documentaire, livré clés en mains et directement applicable, mais de préparer le terrain à l\u27élaboration du futur curriculum, en installant un balisage et en éclairant les différentes facettes structurant le projet curriculaire

Potential impacts of climate change on agriculture and fisheries production in 72 tropical coastal communities

Climate change is expected to profoundly affect key food production sectors, including fisheries and agriculture. However, the potential impacts of climate change on these sectors are rarely considered jointly, especially below national scales, which can mask substantial variability in how communities will be affected. Here, we combine socioeconomic surveys of 3,008 households and intersectoral multi-model simulation outputs to conduct a sub-national analysis of the potential impacts of climate change on fisheries and agriculture in 72 coastal communities across five Indo-Pacific countries (Indonesia, Madagascar, Papua New Guinea, Philippines, and Tanzania). Our study reveals three key findings: First, overall potential losses to fisheries are higher than potential losses to agriculture. Second, while most locations (> 2/3) will experience potential losses to both fisheries and agriculture simultaneously, climate change mitigation could reduce the proportion of places facing that double burden. Third, potential impacts are more likely in communities with lower socioeconomic status

A Net Energy Analysis of the Global Agriculture, Aquaculture, Fishing and Forestry System

The global agriculture, aquaculture, fishing and forestry (AAFF) energy system is subject to three unsustainable trends: (1) the approaching biophysical limits of AAFF; (2) the role of AAFF as a driver of environmental degradation; and (3) the long-term declining energy efficiency of AAFF due to growing dependence on fossil fuels. In response, we conduct a net energy analysis for the period 1971–2017 and review existing studies to investigate the global AAFF energy system and its vulnerability to the three unsustainable trends from an energetic perspective. We estimate the global AAFF system represents 27.9% of societies energy supply in 2017, with food energy representing 20.8% of societies total energy supply. We find that the net energy-return-on-investment (net EROI) of global AAFF increased from 2.87:1 in 1971 to 4.05:1 in 2017. We suggest that rising net EROI values are being fuelled in part by ‘depleting natures accumulated energy stocks’. We also find that the net energy balance of AAFF increased by 130% in this period, with at the same time a decrease in both the proportion of rural residents and also the proportion of the total population working in AAFF—which decreased from 19.8 to 10.3%. However, this comes at the cost of growing fossil fuel dependency which increased from 43.6 to 62.2%. Given the increasing probability of near-term fossil fuel scarcity, the growing impacts of climate change and environmental degradation, and the approaching biophysical limits of global AAFF, ‘Odum’s hoax’ is likely soon to be revealed

Central CD4+ T cell tolerance: deletion versus regulatory T cell differentiation

The diversion of MHC class II-restricted thymocytes into the regulatory T (Treg) cell lineage, similarly to clonal deletion, is driven by intrathymic encounter of agonist self-antigens. Somewhat paradoxically, it thus seems that the expression of an autoreactive T cell receptor is a shared characteristic of T cells that are subject to clonal deletion and those that are diverted into the Treg cell lineage. Here, we discuss how thymocyte-intrinsic and -extrinsic determinants may specify the choice between these two fundamentally different T cell fates

Effective monitoring of freshwater fish

Freshwater ecosystems constitute only a small fraction of the planet’s water resources, yet support much of its diversity, with freshwater fish accounting for more species than birds, mammals, amphibians, or reptiles. Fresh waters are, however, particularly vulnerable to anthropogenic impacts, including habitat loss, climate and land use change, nutrient enrichment, and biological invasions. This environmental degradation, combined with unprecedented rates of biodiversity change, highlights the importance of robust and replicable programmes to monitor freshwater fish assemblages. Such monitoring programmes can have diverse aims, including confirming the presence of a single species (e.g. early detection of alien species), tracking changes in the abundance of threatened species, or documenting long-term temporal changes in entire communities. Irrespective of their motivation, monitoring programmes are only fit for purpose if they have clearly articulated aims and collect data that can meet those aims. This review, therefore, highlights the importance of identifying the key aims in monitoring programmes, and outlines the different methods of sampling freshwater fish that can be used to meet these aims. We emphasise that investigators must address issues around sampling design, statistical power, species’ detectability, taxonomy, and ethics in their monitoring programmes. Additionally, programmes must ensure that high-quality monitoring data are properly curated and deposited in repositories that will endure. Through fostering improved practice in freshwater fish monitoring, this review aims to help programmes improve understanding of the processes that shape the Earth's freshwater ecosystems, and help protect these systems in face of rapid environmental change

How people value different ecosystems within the Great Barrier Reef

International audienc

Ecological evaluation of a marine protected area network: a progressive-change BACIPS approach

International audienceMarine protected area (MPA) networks, with varying degrees of protection and use, can be use ful tools to achieve both conservation and fisheries management benefits. Assessing whether MPA networks meet their objectives requires data from Before the establishment of the network to better discern natural spatiotemporal variation and preexisting differences from the response to protection. Here, we use a Progressive-Change BACIPS approach to assess the ecological effects of a network of five fully and three moderately protected MPAs on fish communities in two coral reef habitats (lagoon and fore reef) based on a time series of data collected five times (over three years) Before and 12 times (over nine years) After the network’s establishment on the island of Moorea, French Polynesia. At the network scale, on the fore reef, density and biomass of harvested fishes increased by 19.3% and 24.8%, respectively, in protected areas relative to control fished areas. Fully protected areas provided greater ecological benefits than moderately protected areas. In the lagoon, density and biomass of harvested fishes increased, but only the 31% increase in biomass in fully protected MPAs was significant. Non-harvested fishes did not respond to protection in any of the habitats. We propose that these responses to protection were small, relative to other MPA assessments, due to limited compliance and weak surveillance, although other factors such as the occurrence of a crownof-thorns starfish outbreak and a cyclone after the network was established may also have impeded the ability of the network to provide benefits. Our results highlight the importance of using fully protected MPAs over moderately protected MPAs to achieve conservation objectives, even in complex social–ecological settings, but also stress the need to monitor effects and adapt management based on ongoing assessments

Erect macroalgae influence epilithic bacterial assemblages and reduce coral recruitment

Macroalgal competition can indirectly influence the health of corals and their response to changing environmental conditions by altering their associated bacterial community. However, the effect of macroalgae on the composition of epilithic microbial biofilms, an important determinant of coral recruitment, is poorly known. In the back-reefs of Moorea (French Polynesia), we evaluated how the experimental removal of either the canopy of the seaweed Turbinaria ornata or that of the entire macroalgal assemblage influenced the composition of the bacterial biofilm and coral recruitment on macroalga-free substrata. The number of bacterial colonies on culture plates inoculated with dilutions of 9 d old biofilm from canopy removal sites was smaller compared with control sites. After 3.5 mo, the diversity of bacterial operational taxonomic units (OTUs) was lower at both canopy and total macroalgal removal sites. Total macroalgal removal sites had a lower relative abundance of several bacterial families, including Rhodobacteraceae, Erythrobacteraceae, Cyanobacteria Family IV and Family VIII, Flavobacteriaceae and Verrucomicrobiaceae. After 8 mo, coral recruitment was generally low, but greater at total macroalgal removal sites. The relative abundance of Cyanobacteria, Sphingo bacteria and Verrucomicrobia was negatively correlated with coral recruitment and explained similar to 70% of variation in coral recruit density. Our study shows that the removal of T. ornata and understory macroalgae influences the composition of epilithic bacterial assemblages and coral recruitment. Thus, eradication campaigns are unlikely to sustain long-term reductions in the abundance of T. ornata and, hence, increase coral recruitment, when plant holdfasts and understory macroalgae are left in place