Updating temperature and salinity mean values and trends in the Western Mediterranean: the RADMED project

Postprin

Unravelling the drivers of variability in body condition and reproduction of the European sardine along the Atlantic-Mediterranean transition

Body condition and reproduction data are broadly used to assess the health status of fish because of its implications for recruitment and ecosystem structure. Sardina pilchardus is a small pelagic distributed throughout both Mediterranean and Eastern Atlantic. Seasonal trend analysis of energy storage and reproduction was carried out in sardines from two areas along the Atlantic-Mediterranean transition: Southern Portugal-Gulf of Cádiz (POR-GC) (Atlantic Ocean) and Alboran Sea (Alb) (Mediterranean Sea) from 2019 to 2021. Energetic condition was estimated using tissue and mesenteric fat content, hepatosomatic index (HSI), and the relative condition factor (Kn). Sex, reproductive developmental stage, and gonadosomatic index (GSI) were also obtained. In addition, the oceanographic and meteorological characteristics of the areas were analysed. Results showed that seasonal Kn, tissue and mesenteric fat content, and HSI values of POR-GC specimens exceeded Alb's with summer arrival, period in which sardine acquires reserves to allocate them to reproduction. These differences could be associated to greater productivity of the former area mainly due to rivers discharges and trade winds intensification during summer (from July to September). Furthermore, gonad maturation of POR-GC stock occurred before the Alb. However, no spawning capable individuals were identified until February in POR-GC. In contrast, in Alb it was observed a remarkable fraction of spawning capable and active spawner individuals in October. We hypothesized the migration of mature individuals from POR-GC to the spawning areas located in the Alb. Seasonal genetic population studies are required to untangle it and reliably evaluate the environmental effect on the stocks.En prens

Calentamiento y aumento de la salinidad en el Mediterráneo Occidental durante la segunda mitad del siglo XX: Inconsistencias, incertidumbres e influencia del procesado de datos

Many papers that have appeared since the late 1980s have reported trends for the salinity and temperature of the upper, intermediate and deep layers within the western Mediterranean. The review of these works shows that the figures reported depend on the period of time considered. In some cases, opposite results are obtained by different studies dealing with the same period of time. These results make it difficult to assess the mean trends of these variables during the second half of the 20th century and to distinguish long-term changes from decadal and multi-decadal variability. In order to determine the origin of these discrepancies, we analyse temperature and salinity profiles from MEDAR/2002 in three areas of the western Mediterranean: the Gulf of Lions, the Balearic Islands and the Alboran Sea. We use data analysis methods that have all been tested and used previously in the literature. Our results show that the scarcity of data makes trend estimations very sensitive to the data analysis methods, questioning the robustness of such estimations and showing the suitability of systematic sampling for studying long-term changes. We attempt to provide temperature and salinity trends from 1950 to 2000 for the three aforementioned regions, which show a higher degree of uncertainty than the previous studies. Long-term temperature and salinity increases for this 50-year period are within the intervals [0.02°C, 0.19°C] and [0.01, 0.1] for deep waters, [0.06°C, 0.38°C] and [0.01, 0.26] for LIW, and [0, 0.45°C] for the upper layers. No salinity change has been observed for the upper layer.Numerosos trabajos aparecidos desde finales de la década de los 80 han mostrado tendencias para la temperatura y salinidad de las capas superficial, intermedia y profunda en el Mediterráneo Occidental. La revisión de estos trabajos muestra que las tendencias calculadas dependen del periodo de tiempo considerado. En algunos casos, trabajos que consideran el mismo periodo de tiempo muestran resultados opuestos lo que hace difícil determinar cuáles han sido los cambios de estas variables a lo largo de la segunda mitad del siglo XX, así como distinguir estos cambios a largo plazo de la variabilidad decadal y multidecadal. Con el objeto de esclarecer el origen de estas discrepancias, analizamos todos los perfiles de temperatura y salinidad disponibles en MEDAR/2002 en tres zonas del Mediterráneo Occidental: Golfo de León, Islas Baleares y Mar de Alborán. Cada serie temporal es analizada usando distintos métodos, siendo todos ellos correctos y previamente usados en la literatura existente. Nuestros resultados muestran que la escasez de datos hace la estimación de tendencias muy sensible al método de análisis de los datos, lo que cuestiona la robustez de estas estimaciones. En este trabajo se obtienen nuevas estimaciones para las tendencias de la temperatura y salinidad desde 1950 al año 2000 para las tres áreas geográficas ya mencionadas, proporcionando incertidumbres mayores que las consideradas en trabajos previos. Los incrementos medios para la temperatura y la salinidad en este periodo de 50 años estarían dentro de los intervalos [0.02ºC, 0.19ºC] y [0.01, 0.1] para las aguas profundas, [0.06ºC, 0.38ºC] y [0.01, 0.26] para el Agua Levantina Intermedia, y [0ºC, 0.45ºC] para las capas superficiales. No se observan cambios de salinidad para esta última capa

Utilización de la densidad de incidencia, en la valoración de faciores de riesgo de la infección nosocomial

ResumenEn la literatura se han propuesto las medidas de densidad de incidencia para la valoración de la infección nosocomial. A través de una cohorte retrospectiva de 843 pacientes se realiza una comparación entre la razón de densidades de incidencia (RDI) y el cociente de incidencias acumuladas o riesgo relativo (RR) en la cuantificación de factores de riesgo de la infección hospitalaria. Las variables que se analizaron fueron la intervención quirúrgica, su duración, el tipo de cirugía, la gravedad de la enfermedad subyacente y la edad. En todas las situaciones la RDI fue inferior al RR, al eliminar la prolongación de estancia producida por los distintos factores de riesgo. Ejemplos de ello fueron el que la RDI para la operación fue de 2,78, mientras que el RR ofreció valores de 6,46, o en la edad, donde los mayores de 60 años presentaron un RR significativo de 1,67, mientras que la RDI fue de 0,96. Esto sugiere que el empleo de la RDI facilitaría la comparabilidad de los resultados entre diferentes centros en la cuantificación de factores de riesgo para la infección nosocomial, aparte de cuantificar con más exactitud los distintos factores de riesgo, lo que tiene importancia a la hora de establecer las medidas de control.SummarySeveral authors have suggested that incidence density should be used in studying nosocomial infection. We assess several risk factors for hospital infection by two ratios, the incidence density ratio (IDR) and the relative risk (RR), in an historical cohort of 843 patients. The variables analyzed were: operation, its length, type of surgical wound, severity of underlying disease, and age. The IDR figures were always lower than those yielded by the RR. For example, the IDR for operated patients was 2.78, whereas RR yielded a figure of 6.46, or the IDR for patients >60 years old was 0.96, whereas the RR achieved a significant value of 1.67. This suggests that the use of IDR lo analyze risk factors for nosocomial infection improves comparability of results obtained in different hospital settings. Also, it may allow a more exact quantification of an effect. These facts influence implementation of nosocomial infection control measures

About the origin of the Mediterranean Waters warming during the twentieth century

En prens

Circulation of water masses through the Ibiza Channel

Publicado

Comparative pattern of Octopus vulgaris life cycle with environmental parameters in the Northern Alboran Sea (Western Mediterranean Sea)

Versión del edito

Long-Term Changes, Inter-Annual, and Monthly Variability of Sea Level at the Coasts of the Spanish Mediterranean and the Gulf of Cádiz

En prensa1,42

Chapter 4.The oceanographic and climatic context

The Alboran Sea is the westernmost basin of the Mediterranean Sea. It is the first one receiving the Atlantic waters flowing through the Strait of Gibraltar and the last one crossed by Mediterranean waters on their way out to the Atlantic Ocean. Therefore, the main factor that determines the Alboran Sea circulation and its water mass distribution is the Atlantic–Mediterranean exchange forced by climatic conditions within the Mediterranean Sea and the Strait of Gibraltar geometry. This general circulation exhibits very strong energetic dynamics with the alternation of cyclonic and anticyclonic circulation cells. The Alboran Sea circulation is highly variable in time at different scales. Some of the shortest ones are semidiurnal and diurnal, associated to the tidal dynamics. The sub-inertial time scale is mainly linked to the wind and atmospheric pressure field variability, and affects the main circulation patterns of the Alboran Sea. Seasonal variability and long-term changes associated with decadal or even longer term changes are caused by alterations in the heat and freshwater fluxes between the Mediterranean Sea, the atmosphere, the nearby Atlantic Ocean and the river basins on land. These changes directly affect the temperature and salinity of the water masses within the Alboran Sea, while it is difficult to predict how they could affect their circulation and dynamics. In this chapter, some of the observed trends in the Alboran Sea water masses are presented. These changes include temperature and salinity increases of the water column, very likely caused by the current climate change process.En prens