Short-Lived Trace Gases in the Surface Ocean and the Atmosphere

The two-way exchange of trace gases between the ocean and the atmosphere is important for both the chemistry and physics of the atmosphere and the biogeochemistry of the oceans, including the global cycling of elements. Here we review these exchanges and their importance for a range of gases whose lifetimes are generally short compared to the main greenhouse gases and which are, in most cases, more reactive than them. Gases considered include sulphur and related compounds, organohalogens, non-methane hydrocarbons, ozone, ammonia and related compounds, hydrogen and carbon monoxide. Finally, we stress the interactivity of the system, the importance of process understanding for modeling, the need for more extensive field measurements and their better seasonal coverage, the importance of inter-calibration exercises and finally the need to show the importance of air-sea exchanges for global cycling and how the field fits into the broader context of Earth System Science

Aceptabilidad de ensilado de alga parda (Lessonia trabeculata) por el abalon rojo (Haliotis rufescens) en condiciones experimentales

The nutritional value during the preparation and conservation of the silage is still of great interest for human and animal consumption. The objective of the study was to demonstrate if the Red abalone (Haliotis rufescens) consumes the silage of Brown seaweed (Lessonia trabeculata) under experimental conditions, on the Morro Sama-Tacna FONDEPES aquaculture Centre, during the years 2017 and 2018. We experimented with the control group (fresh seaweed) and two types of silage, treatments: T1 (silage 0% on dry basis) and T2 (silage 35% on dry basis) for 62 days; determining the content of proteins, fats, carbohydrates and energy in the fresh seaweed, no statistically significant difference (p < 0.05) were observed between the treatments, except for the fat content. Treatments, food acceptance was observed during 10 days and food consumption, sizes and weights were estimated with statistically similar. It was concluded that the abalone eat silage and the highest percentages of bromatological composition corresponded to T2, its consumption to gain weight and height of Haliotis rufescens where probably these variables increase when there is a higher percentage of silage based on dry matter or more days of consumption. Microbiological analysis showed that the silages are suitable for the consumption of the species.   El valor nutricional durante la preparación y conservación de los ensilados sigue siendo de gran interés para el consumo humano y animal. El objetivo del estudio fue demostrar si el abalón rojo (Haliotis rufescens) consume el ensilado de alga parda (Lessonia trabeculata) en condiciones experimentales, en el Centro Acuícola de Morro Sama-Tacna FONDEPES, durante los años 2017 y 2018. Se experimentó con el grupo control (alga fresca) y dos tipos de ensilado, tratamientos: T1 (ensilado 0% en base seca) y T2 (ensilado 35% en base seca) durante 62 días; determinándose en el alga fresca el contenido de proteínas, grasas, hidratos de carbono y energía, no se observó diferencias estadísticamente significativas (p<0.05) entre los tratamientos, excepto para el contenido de grasas. En los tratamientos, se observó la aceptación del alimento durante 10 días y se estimó el consumo del alimento, las tallas y pesos que fueron estadísticamente similares. Se concluyó que: los abalones consumen el ensilado y que los mayores porcentajes de la composición bromatológica correspondió al T2, su consumo para la ganancia de peso y talla de Haliotis rufescens donde probablemente, estas variables aumenten cuando exista mayor porcentaje del ensilado con base en materia seca o mayores días de consumo. El análisis microbiológico demostró que los ensilados son aptos para el consumo de la especie.  &nbsp

Behavior of iodine in the soil-plant system

In order to understand the behaviour of radioactive and stable iodine in the environment, we have carried out radiotracer experiments and chemical analyses in the soil-plant systems. Parameters important for the assessment of radioiodine movement from the environment to man, e.g. soil-plant transfer factors for various agricultural crops and soil-solution distribution coefficient for different soils, were obtained. Mechanisms of iodine sorption and desorption on soil were also studied. Microorganisms and/or their products (e.g. enzymes) were found to play an important role in the fixation of iodine on soil. Iodine was observed to be desorbed from the flooded soils due to the reducing conditions (low Eh) created by the microbial activities. From the soil-rice plant system biogenesis methyl iodide was found to be evaporated into the atmosphere. Through experiment using 125I tracer, we found that volatile organic iodine was produced due to microbial activities (including bacterial activities)