513 research outputs found

    Impact of pulsed direct current on embryos, larvae, and young juveniles of Atlantic cod and its implications for electrotrawling of brown shrimp

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    The application of electrical pulses in fishing gear is considered a promising option to increase the sustainability of demersal trawl fisheries. In the electrotrawl fishery for brown shrimp Crangon crangon, an electrical field selectively induces a startle response in the shrimp. Other benthic organisms remain mainly on the seafloor and escape underneath a hovering trawl. Previous experiments have indicated that this pulse has no short-term major harmful effects on adult fish and invertebrates. However, the impact on young marine life stages is still unknown. Because brown shrimp are caught in shallow coastal zones and estuaries, which serve as important nurseries or spawning areas for a wide range of marine species, electrotrawling on these grounds could harm embryos, larvae, and juveniles. We carried out experiments with different developmental stages of Atlantic Cod Gadus morhua, which are considered vulnerable to electrical pulses. Three embryonic stages, four larval stages, and one juvenile stage of Atlantic Cod were exposed to a homogeneous electrical field of 150 V-peak/m for 5 s, mimicking a worst-case scenario. We detected no significant differences in embryo mortality rate between control and exposed groups. However, for the embryonic stage exposed at 18 d postfertilization, the initial hatching rate was lower. Larvae that were exposed at 2 and 26 d posthatch exhibited higher mortality rates than the corresponding nonexposed control groups. In the other larval and juvenile stages, no short-term impact of exposure on survival was observed. Morphometric analysis of larvae and juveniles revealed no differences in measurements or deformations of the yolk, notochord, eye, or head. Although exposure to a worst-case electrical field did not impact survival or development for six of the eight young life stages of Atlantic Cod, the observed delayed hatching rate and decreased survival for larvae might indicate an impact of electric pulses and warrant further research

    Different Behavior of Enteric Bacteria and Viruses in Clay and Sandy Soils after Biofertilization with Swine Digestate

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    Enteric pathogens from biofertilizer can accumulate in the soil, subsequently contaminating water and crops. We evaluated the survival, percolation and leaching of model enteric pathogens in clay and sandy soils after biofertilization with swine digestate: PhiX-174, mengovirus (vMC0), Salmonella enterica Typhimurium and Escherichia coli O157:H7 were used as biomarkers. The survival of vMC0 and PhiX-174 in clay soil was significantly lower than in sandy soil (ıPT90 values of 10.520 0.600 vs. 21.270 1.100 and 12.040 0.010 vs. 43.470 1.300, respectively) and PhiX- 174 showed faster percolation and leaching in sandy soil than clay soil (ıPT90 values of 0.46 and 2.43, respectively). S. enterica Typhimurium was percolated and inactivated more slowly than E. coli O157:H7 (ıPT90 values of 9.340 0.200 vs. 6.620 0.500 and 11.900 0.900 vs. 10.750 0.900 in clay and sandy soils, respectively), such that E. coli O157:H7 was transferred more quickly to the deeper layers of both soils evaluated (percolation). Our findings suggest that E. coli O157:H7 may serve as a useful microbial biomarker of depth contamination and leaching in clay and sandy soil and that bacteriophage could be used as an indicator of enteric pathogen persistence. Our study contributes to development of predictive models for enteric pathogen behavior in soils, and for potential water and food contamination associated with biofertilization, useful for risk management and mitigation in swine digestate recycling.RTA2014-00024-C04-01 from the Spanish Ministry of Economy and Innovation and the Brazilian CNPq Project number 472804/2013-8, an dby CAPES/PNPD and CAPES/PDSE

    What determines women's participation in collective action? Evidence from a western Ugandan coffee cooperative

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    Women smallholders face greater constraints than men in accessing capital and commodity markets in Sub-Saharan Africa. Collective action has been promoted to remedy those disadvantages. Using survey data of 421 women members and 210 nonmembers of a coffee producer cooperative in Western Uganda, this study investigates the determinants of women's participation in cooperatives and women's intensity of participation. The results highlight the importance of access to and control over land for women to join the cooperative in the first place. Participation intensity is measured through women's participation in collective coffee marketing and share capital contributions. It is found that duration of membership, access to extension services, more equal intrahousehold power relations, and joint land ownership positively influence women's ability to commit to collective action. These findings demonstrate the embeddedness of collective action in gender relations and the positive value of women's active participation for agricultural-marketing cooperatives

    Virtual Water Flows in the EU27: A Consumption-based Approach

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    The use of water resources has traditionally been studied by accounting for the volume of water removed from sources for specific uses. This approach focuses on surface and groundwater only and it ignores that international trade of products with substantial amounts of embodied water can have an impact on domestic water resources. Using current economic and environmental data, we conduct a consumption-based assessment of virtual water flows in the European Union (EU27). We find that the total water footprint (WF) of 2,280 cubic meters (m3) per capita for the EU27 mostly consists of green water use (precipitation stored as soil moisture), which is omitted in the conventional water accounting. Blue water (surface and groundwater.) and gray water use (the volume of freshwater needed to dilute pollutants to meet the applicable water quality standards), which are targeted by current EU water policies, only make up 32% of the total WF. We also find that Europeans imported 585 cubic kilometers (km3) (109 m3) of virtual water, or around 28% of global virtual water trade flows, in 2009. Within Europe, Germany is a key net importer of water through the trade of products in agriculture, the food industry, the chemical sector, and electricity generation. Countries in Southern and Eastern Europe have specialized in water-intensive agriculture and are key exporters of virtual water despite experiencing physical scarcity of water. Our results suggest that there is a need to reconsider water policy in the EU to address water transfers occurring through trade and to grasp the interlinkages between green, blue, and gray water—which are likely to become more important in water-scarce parts of Europe, with a changing climate

    Benthic habitat modelling and mapping as a conservation tool for marine protected areas: A seamount in the western Mediterranean

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    1. An ecologically representative, well‐connected, and effectively managed system of marine protected areas (MPAs) has positive ecological and environmental effects as well as social and economic benefits. Although progress in expanding the coverage of MPAs has been made, the application of management tools has not yet been implemented in most of these areas. 2. In this work, distribution models were applied to nine benthic habitats on a Mediterranean seamount within an MPA for conservation purposes. Benthic habitat occurrences were identified from 55 remotely operated vehicle (ROV) transects, at depths from 76 to 700 m, and data derived from multibeam bathymetry. Generalized additive models (GAMs) were applied to link the presence of each benthic habitat to local environmental proxies (depth, slope, backscatter, aspect, and bathymetric position index, BPI). 3. The main environmental drivers of habitat distribution were depth, slope, and BPI. Based on this result, five different geomorphological areas were distinguished. A full coverage map indicating the potential benthic habitat distribution on the seamount was obtained to inform spatial management. 4. The distribution of those habitats identified as vulnerable marine ecosystems (VMEs) was used to make recommendations on zonation for developing the management plan of the MPA. This process reveals itself as an appropriate methodological approach that can be developed in other areas of the Natura 2000 marine networkEn prensa1,92

    Modern Slavery, Environmental Degradation and Climate Change: Fisheries, Field, Forests and Factories

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    In this commentary paper, the current state of research on the tightly connected and bi-directional relationships among modern slavery, environmental degradation and climate change is critically assessed and reviewed. An emerging branch of research has begun to conceptualize linkages between slavery and environmental change. Responding to a gap in the extant literature, this paper synthesizes and makes sense of this emerging research base and proposes a future research agenda for exploring the slavery–environment nexus. Through an exploration of 19 key texts which explicitly examine the relationship between slavery and environmental change, spanning across diverse disciplines and spatial scales, we draw out two key arguments that can be adopted in proposing a future research agenda. Firstly, we identify the sectoral emergence of the nexus, forming primarily around four key sectors: (i) Fisheries, (ii) Fields, (iii) Forests and (iv) Factories. The review suggests that a sufficient exploration of slavery–environment linkages needs to transverse these sectoral boundaries. Secondly, the paper highlights the bi-directional interactions among modern slavery, climate change and environmental degradation. Accordingly, we argue for a holistic lens which explores how slavery practices and environmental change are continually shaping one another. Existing research has provided initial understandings of the relationship among modern slavery, environmental destruction and climate change. However, there remains considerable scope for the connections between the three to be further interrogated and unpacked. Based on the review, the paper sets out three key research agendas, highlighting the need to move beyond a spatially and sectorally confined exploration of slavery–environment interactions towards an integrated and sophisticated interrogation of the nexus. Additionally, we propose the future examination of the deep underlying drivers of slavery–environment interactions and to situate these within contemporary capitalist social and economic relations

    Agriculture, Food Systems, and Nutrition: Meeting the Challenge

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    Malnutrition is a global challenge with huge social and economic costs; nearly every country faces a public health challenge, whether from undernutrition, overweight/obesity, and/or micronutrient deficiencies. Malnutrition is a multisectoral, multi-level problem that results from the complex interplay between household and individual decision-making, agri-food, health, and environmental systems that determine access to services and resources, and related policy processes. This paper reviews the theory and recent qualitative evidence (particularly from 2010 to 2016) in the public health and nutrition literature, on the role that agriculture plays in improving nutrition, how food systems are changing rapidly due to globalization, trade liberalization, and urbanization, and the implications this has for nutrition globally. The paper ends by summarizing recommendations that emerge from this research related to (i) knowledge, evidence, and communications, (ii) politics, governance, and policy, and (iii) capacity, leadership, and financing
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