Intrusiones de la corriente de Kuroshio en el mar de China oriental

[EN]The Kuroshio is known to intrude onto the continental shelf in the southern East China Sea northeast of Taiwan. Two types of intrusions are observed: large and small, depending on how far the Kuroshio penetrates onto the ECS continental shelf, and on the location where it crosses the shelf break. This study demonstrates that cyclonic eddies from the western Pacific induce some of these large Kuroshio intrusions. The large intrusions are identified from more than 20 years of drifter tracks archived in the Global Drifter Program historical database and from weekly and biweekly drifter deployments carried out between April 2008 and September 2009 west of the Green Island (Taiwan). Kuroshio intrusions are observed in all seasons. Cyclonic mesoscale eddies, generated in the Subtropical Countercurrent and North Equatorial Current regions of the northwest Pacific Ocean, propagate westward into the Kuroshio and are well correlated with the observed intrusions. During the intrusions, the mean sea level anomaly computed from AVISO gridded maps shows a well defined cyclonic circulation southeast of the I-Lan ridge. The mean sea level anomaly also shows the meandering pattern of the Kuroshio when it intrudes onto the continental shelf of the southern East China Sea. The high correlation between the Kuroshio volume transport in the East Taiwan Channel (observed with moorings) and the satellite sea level anomaly permits us to use sea level anomaly as a proxy for the Kuroshio volume transport. When direct transport measurements are not available, this proxy is used to verify that intrusions due to the westward propagating eddies occur when the Kuroshio transport is low. An analytical reduced gravity model of an incident baroclinic current upon a step shelf is used to explain the difference between the large and small intrusions.

Exploring respiration and respiratory electron transport system (ETS) in Ulva spp.

[ES] Respiration is a key ecological index. For either individuals or communities, it can be use to assess carbon and energy, demand and expenditure as well as carbon flow rates through food webs. When combined with productivity measurements it can establish the level of metabolic balance. When combined with measurements of respiratory capacity, it can indicate physiological state. Here, we report pilot studies the metabolism of the green algae, Ulva rotundata that inhabits intertidal pools of Gran Canaria. As a starting point we used the electron transport system (ETS) to differentiate between different growing conditions in the natural environment. We suspected different levels of stress associated with these conditions and looked for the influence of this stress in the ETS measurements. This technique has been successfully applied to study bacteria, phytoplankton and zooplankton in the ocean, but it has not been used to study sessile marine macroalgae. These neritic and littoral macrophytes have major ecological and industrial importance, yet little is known about their respiratory physiology. Such knowledge would strengthen our understanding of the resources of the coastal ocean and facilitate its development and best use. Here, we modified the ETS methodology for Ulva rotundata. With this modified ETS assay we investigated the capacity of Ulva to resist anoxia. We measured respiration with optodes (Fibox 4, Presens) in the dark to the point of oxygen exhaustion and through 24 h of anoxia. Then we exposed the Ulva to light and followed the oxygen increase due to photosynthesis. We discuss here the capacity of Ulva to survive during anoxia.

Respiratory electron transport activity in plankton: determinants and detection

[ES]La presente tesis, se centra en el estudio del Sistema de Transporte de Electrones (ETS) en organismos del plancton marino, los factores que lo influencian la interpretación de estas mediciones y su detección mediante espectrofotometría y espectrofluorometría, en muestras oceánicas naturales y en cultivos de organismos marinos. Se pudo establecer, la biomasa, la respiración (R) y la respiración potencial (ɸ), en tres transectos en los océanos Índico y Atlántico Norte Sur. A su vez, se determino el estado fisiológico, en tres tamaños del zooplancton, midiendo la relación R/ɸ. Se exploró los efectos de la inanición sobre la R y la variación con respecto a la ɸ en el zooplancton