Spring influence of the Iberian Poleward Current into the Bay of Biscay from 1987 to 2006

Publicado

Sampling Once…Using Data Multiple Times.

presentaciónMarine ecosystem variability shows large fluctuations on a wide variety of scales, from seconds to millennia and from local to global. This limits our ability to observe these systems and to develop good tools to predict how changes in the environment may affect their physical and biological properties. It also limits our ability to differentiate anthropogenic from natural processes. An example is how difficult it is to compare data collected in different sampling locations and at different times. Time series data help resolve both short- and longer-term scales of variability and provide context for traditional process-oriented studies. Time series projects focusing on biogeochemical and ecological observations have yielded important scientific results. They have helped to: (i) evaluate the statistical significance of the ranges of variability of many parameters and environmental variables and biological communities, and (ii) quantify and evaluate the dimension of the interactions between key physical/chemical oceanographic processes and biological rates in plankton communities. As a result, time series are helping estimate warming rates and trends as well as the effects of global change on biota. They have established reference baselines to evaluate the magnitude of environmental perturbations and estimate recovery times on biodiversity and productivity of specific trophic levels. In spite of their scientific value, marine time series are difficult to maintain over time because of costs and availability of trained personnel. Only a few survive beyond a decade. There is great potential in sharing and combining marine data sets from different time series programs from around the world. This allows for comparisons of changes occurring in distant locations, and helps detect changes that occur at broad scales, perhaps even global scales, and to distinguish them from local imbalances or fluctuation. Sharing data can have important economic and social benefits. For instance, efficient use of existing marine data represents a significant cost saving from the 2 billion Euro spent each year now in the EU collecting and accessing to marine data. From the social point of view, the demand from different stakeholders for answers to the challenges posed by changes in the marine environment is growing rapidly. Sharing and accessing time series data would reduce the uncertainties in the management of marine resources and ecosystem services. The UNESCO IOC advocates that: (i) an observation not made today is lost forever, (ii) existing observations are lost if not made accessible, (iii) the collective value of data sets is greater than its dispersed value, and (iv) open access to standardised time series data must be pursued as a common, coordinated international goal.IOC-UNESCO, IE

Depth and spatial distribution of blue whiting juveniles in Bay of Biscay

During March-April 1994 and 1996 two cruises have been performed around Bay of Biscay in order to check movements of blue whiting using acoustic methods. These cruises consisted in a double coverage of an area from 47°30' N, 7°15' W to 43°30' N, 6°30' W along the French and Spanish continental shelf-break (200 m to 1000 m). During these surveys juveniles of blue whiting were found in off-shore pelagic schools. This paper describes the spatial distribution and depth of these schools around the studied area

Introducción.

Versión del edito

Resumen ejecutivo.

Versión del edito

Seasonality and interannual variability of copepods in the Western English Channel, Celtic Sea, Bay of Biscay, and Cantabrian Sea with a special emphasis to Calanus helgolandicus and Acartia clausi

A total of five mesozooplankton time series data sets were assembled to compare the seasonal and interannual patterns of abundance of calanoid copepods in the Western English Channel (Station L4), Celtic Sea, Bay of Biscay (Continuous Plankton Recorder), and the Cantabrian Sea (RADIALES time series, Santander, St-4 and St-6) from January 1992 to December 1999. A strong seasonal component in taxonomic composition was detected at the locations considered. There was also a strong latitudinal effect on diversity at each location, southernmost locations being more diverse. The seasonal dynamics and year-to-year variability of two copepod species: Calanus helgolandicus and Acartia clausi were studied in detail. A latitudinal pattern in the seasonal cycles of both copepod species was observed. The peaks of both occur earlier in spring in the warmer southern region and move northwards, consistent with the temperature regimes at each location, supporting the broad concept that species occupy a thermal niche in time as well as in space. There was a strong degree of interannual variability between sites and between species. No clear trends, but some coherent events among data sets, reveal a regional response to environmental forcing factors. Correlations suggest possible connections with environmental indices like the North Atlantic Oscillation and the Gulf Stream North Wall index. There was a positive correlation between the NAO and the abundance of C. helgolandicus at station L4 off Plymouth; however, the relationship in the Celtic Sea and Bay of Biscay was opposite to that expected based on previous results. Despite the differences in the sampling techniques used within each dataset, the results are comparable and coherent in terms of taxonomic composition and the seasonal and interannual patterns detected

Chlorophyll and primary production in the North Atlantic.

Versión del edito

Zooplankton composition and distribution off the coast of Galicia, Spain

During June and September 1984, zooplankton samples were collected with other hydrographic and biological data along the Galician coast (NW of Spain). In June copepods contributed -60% to the total zooplankton community, with larvaceans, siphonophores and cladocerans also abundant. In September >90% of the zooplankton sampled were copepods. The dominant species of copepods in both June and September were Acartia e/ausi, Paracalanus parvus and Temora longicornis. The meroplankton was dominated by echinoderms, bryozoans, barnacle larvae and bivalve larvae. In June the average zooplankton biomass was 31.08 mg e m-3; the September average was 41.69 mg e m-3 The relationship between the slopes of the regression equations (biomass versus abundance) suggests that the zooplankton assemblage in June was composed by larger animals than in September. The major concentration of zooplankton was between O and SO m, with both June and September daytime surface samples having 6-7 times the amount of organisms than the lower water column (50-100 m). There were no distinct differences in total zooplankton abundances at the inshore and offshore stations; however, the inshore stations often had a higher percentage of meroplankton than the offshore stations. In June zooplankton abundance at the northern transects and the western transects was similar. In September there were greater concentrations of zooplankton in the western Galician shelf as compared with the northern shelf. These differences in the horizontal distribution of the zooplankton were related to upwelling events.Postprin

COMPOSICION y ABUNDANCIA DEL MICROZOOPLANCTON EN LA PLATAFORMA CONTINENTAL GALLEGA

Se ha estudiado la composición y abundancia del microzooplancton (20-200 mm) en dos estratos de profundidad (0-15 y 15-30 m) en un total de 16 estaciones de muestreo situadas sobre la plataforma continental gallega, durante tres campañas oceanográficas realizadas en verano, otoño y primavera. Los estadios larvarios de organismos holoplanctónicos y meroplanctónicos dominan en la comunidad del microzooplancton. Entre ellos destacan las larvas nauplius de copépodo, cuya abundancia relativa es mayor en primavera (87%) que en verano (40%) y otoño (52%), y las larvas de lamelibranquio que son más abundantes en verano (13%) y otoño (10%) que en primavera (2.5%).Los valores extremos de las abundancias del microzooplancton fueron de 1 y 82 ind 1-1• Las abundancias medias en primavera y verano fueron de 25 y 20 ind 1-1 respectivamente, mientras que en otoño la media fue de 8 ind 1-1• Las larvas nauplius no presentan una distribución de abundancias localizada en una zona determinada de la plataforma continental, en cambio, las larvas de lamelibranquio son más abundantes en las estaciones situadas frente alas Rías de Vigo y Arosa que en las situadas frente a la Ría de Muros, Cabo Vilano y La Coruña.Postprin

Directory of Atmospheric, Hydrographic and Biological datasets for the Canary Current Large Marine Ecosystem

Environmental and biological data-sets were recovered from oceanographic surveys and other observation sources (e.g. tide gauges) since the 40s. This rescue and mining exercise was carried out in cooperation with the countries bordering the CCLME and other nations undertaking research in the region (i.e. Morocco, Mauritania, Senegal, Gambia, Guinea, Guinea Bissau, Cape Verde, Spain, Norway, Germany and France). A total of 425 data-sets, 27 databases and 21 time-series sites have been identified in the area. A substantial part of them were rescued from archives supported in paper copy. Finally, a directory of meta-data referring 99 data-sets and data-bases has been published. This catalogue and the recovered data offer an exceptional opportunity for the researchers in the CCLME to study the dynamics and trends of a multiplicity of variables, and will enable them to create their own time-series, baselines and climatologies under a spatial and temporal perspective. It will produce new and valuable information on changes produced during the last 35 years in this region, going from climatic changes to shifts in species diversity and populations due to natural and human induced factors. This directory is the first result of the project “Enhancing oceanography capacities on Western Africa Countries” funded by the Spanish Agency for International Development Cooperation (AECID) and coordinated by the IOC-UNESCO and the IEO. The project aims to reinforce transboundary cooperation in the CCLME and to facilitate access and data flow to existing scientific information and its utilization by the scientists, politicians, industry and civil society.http://unesdoc.unesco.org/images/0023/002314/231430E.pd