Diversity in reproductive traits of arapaima (Arapaima spp., Müller, 1843) in Amazonian várzea floodplains: Conservation implications

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The status of marine biodiversity in the Eastern Central Atlantic (West and Central Africa)

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Estimating the ecological,economic and social impacts of ocean acidification and warming on UK fisheries

Assessments of the combined ecological impacts of ocean acidification and warming (OAW) and their social and economic consequences can help develop adaptive and responsive management strategies in the most sensitive regions. Here, available observational and experimental data, theoretical, and modelling approaches are combined to project and quantify potential effects of OAW on the future fisheries catches and resulting revenues and employment in the UK under different CO₂ emission scenarios. Across all scenarios, based on the limited available experimental results considered, the bivalve species investigated were more affected by OAW than the fish species considered, compared with ocean warming alone. Projected standing stock biomasses decrease between 10 and 60%. These impacts translate into an overall fish and shellfish catch decrease of between 10 and 30% by 2020 across all areas except for the Scotland >10 m fleet. This latter fleet shows average positive impacts until 2050, declining afterwards. The main driver of the projected decreases is temperature rise (0.5–3.3 °C), which exacerbate the impact of decreases in primary production (10–30%) in UK fishing waters. The inclusion of the effect of ocean acidification on the carbon uptake of primary producers had very little impact on the projections of potential fish and shellfish catches (<1%). The <10 m fleet is likely to be the most impacted by‐catch decreases in the short term (2020–50), whereas the effects will be experienced more strongly by the >10 m fleet by the end of the century in all countries. Overall, losses in revenue are estimated to range between 1 and 21% in the short term (2020–50) with England and Scotland being the most negatively impacted in absolute terms, and Wales and North Ireland in relative terms. Losses in total employment (fisheries and associated industries) may reach approximately 3–20% during 2020–50 with the >10 m fleet and associated industries bearing the majority of the losses.     

Comparison of herbicide regimes and the associated potential environmental effects of glyphosate-resistant crops versus what they replace in Europe

While cultivation of transgenic crops takes place in seven of the EU member states, this constitutes a relatively limited part of the total acreage planted to these crops worldwide. The only glyphosate-resistant (GR) crop grown commercially until recently has been soybean in Romania. In addition, large-scale experimental European data exist for GR sugar and fodder beets, and, to a lesser extent, GR oilseed rape. These GR crops are likely to have an impact both on the use of herbicides and on the environmental impact of the latter. From the data on these GR crops, it appears that quantities of herbicides applied to GR beets are decreased while those on GR soybean are slightly increased compared with their conventional counterparts. Depending on the parameters used for prediction or measurement of environmental impacts of GR crops, generally similar or less negative impacts were observed compared with conventional crops. Favourable environmental effects of the glyphosate-containing herbicide regimes on GR crops appear feasible, provided appropriate measures for maintaining biodiversity and prevention of volunteers and gene flow are applied.     

Small‐scale fisheries through the wellbeing lens

Despite longstanding recognition that small‐scale fisheries make multiple contributions to economies, societies and cultures, assessing these contributions and incorporating them into policy and decision‐making has suffered from a lack of a comprehensive integrating ‘lens’. This paper focuses on the concept of ‘wellbeing’ as a means to accomplish this integration, thereby unravelling and better assessing complex social and economic issues within the context of fisheries governance. We emphasize the relevance of the three key components of wellbeing – the material, relational and subjective dimensions, each of which is relevant to wellbeing at scales ranging from individual, household, community, fishery to human‐ecological systems as a whole. We review nine major approaches influential in shaping current thinking and practice on wellbeing: the economics of happiness, poverty, capabilities, gender, human rights, sustainable livelihoods, vulnerability, social capital, and social wellbeing. The concept of identity is a thread that runs through the relational and subjective components of social wellbeing, as well as several other approaches and thus emerges as a critical element of small‐scale fisheries that requires explicit recognition in governance analysis. A social wellbeing lens is applied to critically review a global body of literature discussing the social, economic and political dimensions of small‐scale fishing communities, seeking to understand the relevance and value addition of applying wellbeing concepts in small‐scale fisheries.     

BIOECONOMICS OF RESERVOIR AQUACULTURE IN VIETNAM

Reservoir aquaculture has developed in an ad hoc manner in Vietnam to date. A bioeconomic model of reservoir aquaculture in northern Vietnam is presented in this paper to highlight issues of developmental importance of reservoir aquaculture in Vietnam. The biological model is based on a conventional von Bertalanffy growth function and the economic model is a net revenue function. The greatest source of costs for the operation are restocking costs (75%) and contract labor costs (18 percent). Benchmark net revenue is approximately 8.7 million VND (approximately US$539). The stocking density, length of time between stocking and harvest and harvesting efficiency have the largest impact on net revenue. The inclusion of aquaculture into government fisheries development plans with research focused on development of fingerling production, preparation of flooded land for aquaculture production and strengthening institutional arrangements for reservoir leasing and credit arrangements, is likely to lead to increased capitalization and investment, and therefore greater revenues for local fishing populations.     

Perceptions of fishing access restrictions and the disparity of benefits among stakeholder communities and nations of south‐eastern Africa

Achieving high compliance with resource‐use management policies is a critical concern to achieving sustainability, particularly in poor countries. Willingness to comply may depend on the values and perceptions of benefits and legitimacy of the restrictions. Consequently, we interviewed and evaluated the perceptions of fishing restrictions among ~2100 marine fisheries stakeholders (resource users and managers) in 102 fishing villages in Kenya, Madagascar, Mozambique and Tanzania. We hypothesized that perceived benefits would decline and social inequity increase along a hypothesized gradient of increasing access restriction – ranging from minimum size of fish to fisheries closures. Managers did not recognize the hypothesized access restriction gradient, seeing most restrictions as beneficial, but with some nation‐specific distinctions. Village‐level responses of resource users varied by country, and overall perceived benefits of access restrictions increased with the wealth, education and membership in fishing organizations. In Kenya and Tanzania, some communities with views that differed greatly from managers were, in places, found near marine protected areas and they perceived more benefits accruing to the government than resource users for the strongest access restrictions. Madagascar and Mozambique fishing villages had low between‐community variability, and their responses did not reflect the hypothesized restriction gradient or strong social disparity, which may reflect limited practical experience with restrictions. These results suggest that countries with stronger central governments contained villages with more between‐community variability and perceived social disparity than weaker governments. We argue that transparent negotiations with stakeholders about the scales of costs and benefits should increase compliance with selected fisheries regulations.     

Dynamics of serum antibodies to and load of porcine circovirus type 2 (PCV2) in pigs in three finishing herds,affected or not by postweaning multisystemic wasting syndrome

Background

Despite that PMWS commonly affects pigs aged eight to sixteen weeks; most studies of PMWS have been conducted during the period before transfer to finishing herds. This study focused on PCV2 load and antibody dynamics in finishing herds with different PMWS status.

Methods

Sequentially collected blood samples from 40 pigs in each of two Swedish (A and B) and one Norwegian (C) finishing herds were analysed for serum PCV2-load and -antibodies and saliva cortisol. The two Swedish herds differed in PMWS status, despite receiving animals from the same sow pool (multi-site production). However, the PMWS-deemed herd (A) had previously also received pigs from the spot market. ResultsThe initial serum PCV2 load was similar in the two Swedish herds. In herd A, it peaked after two weeks in the finishing herd and a high number of the pigs had serum PCV2 levels above 10⁷ per ml. The antibody titres increased continually with exception for the pigs that developed PMWS, that had initially low and then declining antibody levels. Pigs in the healthy herd B also expressed high titres of antibodies to PCV2 on arrival but remained at that level throughout the study whereas the viral load steadily decreased. No PCV2 antibodies and only low amounts of PCV2 DNA were detected in serum collected during the first five weeks in the PMWS-free herd C. Thereafter a peak in serum PCV2 load accompanied by an antibody response was recorded. PCV2 from the two Swedish herds grouped into genotype PCV2b whereas the Norwegian isolate grouped into PCV2a. Cortisol levels were lower in herd C than in herds A and B.

Conclusions

The most obvious difference between the Swedish finishing herds and the Norwegian herd was the time of infection with PCV2 in relation to the time of allocation, as well as the genotype of PCV2. Clinical PMWS was preceded by low levels of serum antibodies and a high load of PCV2 but did not develop in all such animals. It is notable that herd A became affected by PMWS after errors in management routine, emphasising the importance of proper hygiene and general disease-preventing measures.     

Bicultures of oat (Avena sativa L.) and grazing vetch (Vicia dasycarpa L.) cover crops increase contents of carbon pools and activities of selected enzymes in a loam soil under warm temperate conditions

This study evaluated effects of oats (Avena sativa L.) and grazing vetch (Vicia dasycarpa L.), bicultures, in rotation with summer maize (Zea mays), on soil organic matter fractions and activities of selected enzymes. The trial was initiated in April 2009. The treatments were 100% oat, 100% vetch, 90% oat + 10% vetch, 70% oat + 30% vetch, 50% oat + 50% vetch, and weedy fallow, in a randomized complete block design (RCBD) with three replications. Soil samples were collected in October 2011, from the 0–5 and 5–20 cm depths, and analyzed for total carbon (C), particulate organic matter (POM), water-soluble carbon (WSC), microbial biomass carbon (MBC) and activities of selected enzymes. Total C was higher in bicultures, particularly the 70% oat + 30% vetch, and 100% vetch than in 100% oats and the control. The greatest MBC, WSC, dehydrogenase, aryl-sulphatase and phosphomonoesterase activities were in the 70% oat + 30% vetch biculture, and declined where the proportion of oats or vetch was higher. Increasing proportions of vetch resulted in increases in urease and β-glucosidase activity and decrease in POM. The findings suggested that, in addition to increased maize yields, bicultures of oats and vetch also have synergistic effects on soil carbon pools and enzyme activities, with potential benefits of improved soil physical condition and nutrient cycling compared with the individual crops, under warm temperate conditions.