Paleolimnology of the San Roque reservoir. Relationship between eutrophication and hydroclimatic variability

El presente trabajo tuvo como objetivo evaluar la historia trófica del Embalse San Roque, vinculada a la eutrofización y la variación hidroclimática. Para ello se analizaron indicadores físicos, químicos y biológicos (paleopigmentos) en un testigo sedimentario. Esta información fue correlacionada con datos hidroclimáticos- precipitaciones y nivel del embalse-. Los resultados indican que existen una asociación entre la productividad del sistema con períodos más húmedos. Además, se observó un incremento de la productividad en los últimos años debido al aumento de los aportes autóctonos. Sin embargo, se requieren más análisis que confirmen estas relaciones.Centro de Investigaciones Geológica

Paleolimnology of the San Roque reservoir. Relationship between eutrophication and hydroclimatic variability

El presente trabajo tuvo como objetivo evaluar la historia trófica del Embalse San Roque, vinculada a la eutrofización y la variación hidroclimática. Para ello se analizaron indicadores físicos, químicos y biológicos (paleopigmentos) en un testigo sedimentario. Esta información fue correlacionada con datos hidroclimáticos- precipitaciones y nivel del embalse-. Los resultados indican que existen una asociación entre la productividad del sistema con períodos más húmedos. Además, se observó un incremento de la productividad en los últimos años debido al aumento de los aportes autóctonos. Sin embargo, se requieren más análisis que confirmen estas relaciones.Centro de Investigaciones Geológica

An assessment of economic viability of the Ascension Island tuna longline fishery management: implications for marine protected area planning and future fisheries management

The designation of large scale marine protected areas (MPAs) has increased in recent years to address global issues such as biodiversity loss and the conservation of vulnerable marine habitats. While designing a large scale MPAs in the Exclusive Economic Zone (EEZ) of Ascension Island, the monitoring and enforcement costs were estimated for the two options under consideration: partial closure or full closure of the EEZ for the international commercial fleet. It was found that number of licenses to be sold to the international fleet to allow them access to the EEZ of Ascension Island would need to be increased to fund the monitoring and enforcement cost in case of a partial closure of the EEZ of Ascension Island. In this study, the future economic viability of the licensed big eye tuna fishery was addressed. The study explored economic drivers thought to be linked to license sales. It was shown that cost of licenses had not caused the observed decline in license sales but a shift in consumer demand toward lighter tuna species resulted in a decrease in Japanese imports for bigeye tuna (Thunnus obesus). This change in demand led to global changes in fishing effort and a drop in demand for licenses to fish within the Ascension Island EEZ. This study provided a valuable insight into the economic viability of the bigeye tuna fishery within the Ascension Island EEZ which informed the subsequent decision to close the bigeye tuna fishery as part of the designation of an Ascension Island highly protected large-scale MPA

Rapid Discrimination of Salmonella enterica Serovar Typhi from Other Serovars by MALDI-TOF Mass Spectrometry

Systemic infections caused by Salmonella enterica are an ongoing public health problem especially in Sub-Saharan Africa. Essentially typhoid fever is associated with high mortality particularly because of the increasing prevalence of multidrug-resistant strains. Thus, a rapid blood-culture based bacterial species diagnosis including an immediate sub-differentiation of the various serovars is mandatory. At present, MALDI-TOF based intact cell mass spectrometry (ICMS) advances to a widely used routine identification tool for bacteria and fungi. In this study, we investigated the appropriateness of ICMS to identify pathogenic bacteria derived from Sub-Saharan Africa and tested the potential of this technology to discriminate S. enterica subsp. enterica serovar Typhi (S. Typhi) from other serovars. Among blood culture isolates obtained from a study population suffering from febrile illness in Ghana, no major misidentifications were observed for the species identification process, but serovars of Salmonella enterica could not be distinguished using the commercially available Biotyper database. However, a detailed analysis of the mass spectra revealed several serovar-specific biomarker ions, allowing the discrimination of S. Typhi from others. In conclusion, ICMS is able to identify isolates from a sub-Saharan context and may facilitate the rapid discrimination of the clinically and epidemiologically important serovar S. Typhi and other non-S. Typhi serovars in future implementations