New Local-scale hydrographic observation on the Flemish Cap in July 1996

8 pages, 7 figures.The research cruise "FC96" was made on the Flemish Cap area on board the RV Cornide de Saavedra from 28 June to 14 July 1996. The survey consisted of a series of 121 random bottom trawls over Flemish Cap inside the boundaries of the 732 m isobath. A CTD station was established either at the beginning or at the end of each trawl for a total of 116 stations. Three different water masses were detected. Two of them are already known: (a) Labrador Current waters, spreading around the Bank; (b) Central Cap seawater, the solar heated Labrador waters retained over the Cap. These waters made an anti-cyclonic gyre of 4–12 cm per sec. Both water masses tended to become stable at 200 m depth, with temperatures about 3.5°C and salinities about 34.85 psu. A third water mass which had not been previously described on Flemish Cap was the Slope Water, found in the southwest area of the Cap between 200–300 m, where it occupied two separate areas with temperatures higher than 4.5°C and salinities higher than 34.90 psu. These intrusions of Slope Water on the Flemish Cap seemed to affect the distribution of some fish species. In particular, they coincided with the breaking of continuity in the geographic distribution of some demersal species, like the redfish Sebastes marinus and S. fasciatusThis paper is a contribution to the UE project "Analysis of exploited fish stocks on Flemish Cap" ref. AIR1-CT92-0558.Peer reviewe

Flows and budgets of nutrient salts and organic carbon in relation to a red tide in the Ria of Vigo (NW Spain)

14 pages, 11 figures, 8 tables.In late September 1986, a major red tide occurred in the Ria of Vigo. Hydrographic conditions led to water retention, with circulation in a semi-closed circuit. In this study nutrient salts and carbon fluxes were calculated, and their consumption quantified, by use of a box model for the ria. The dinoflagellate Gymnodinium catenatum, scarcely present on 4 September, increased in concentration to 10(up 4) cell dm(-3) by 21 September. This was favoured by chemical causes, such as the high availability of ammonium (6.2 mol s(-1) were delivered to the upper water layer) and organic carbon, and by physical causes, such as the rapid circulation (862 X 10 (up to 3) kg s(-l) ) with reducing mixing, almost half that of the preceding date. The nutrient salts came mostly from the remineralisation of organic matter. The amounts contributed by freshwater, 5 % of the total, did not have an appreciable influence on the formation of the red tide. Vertical migration of the dinoflagellate played an important role. It is estimated that this organism was responsible for 22% of the synthesis of nitrogenous organic matter. The red tide came to an end with the November rains, which created rapid circulation which washed out the ria.The I.E.O. of Vigo for their k1nd inntation to then workshop. Specla1 thanks to Prof. Fernando Fraga, head of the project 'Intercambio de nutrientes entre las rias y la plataforma costera en el NO de la peninsula Ibérica'.Peer reviewe

Fluvial transport patterns of dissolved trace metals to the Ria of Cedeira

5 páginas.-- Interdisciplinary Water Congress CINA 2014, Vigo, 2-6 June 2014Samples of water were withdrawn monthly close to the Das Mestas River mouth, out of the tidal influence, from October 2011 to September 2012 (covering a hydrological year). After filtration through 0.45 policarbonate membrane, nine trace metals were analyzed (Al, Co, Cu, Cr, Fe, Mo, Ni, Pb and V) in the dissolved phase. All procedures were made following trace-metal-clean techniques. Three groups of metals were distinguished: Al, Co, Ni, Cu and Pb correlated with the SPM and the DOC indicating they are related with soil leaching; Iron is related with Chl-a so its behavior depends on the biologic activity; lithological influence on Cr, Mo and V patterns was observed.This study was supported by CTM2011-28792-C02 project, Land-sea exchange of trace metals and its importance for marine phytoplankton in an upwelling coast (MITOFE), financed by Spanish MINECOPeer reviewe

Lead and Zinc contamination of surface sediments in the main harbours of the Galician Rias

The concentration ranges and degree of contamination of lead and zinc in the four principal harbour areas of the northwest Iberian Peninsula have been defined from 130 surface sediment samples (A partir de la fracción fina en 130 muestras de sedimento superficial se han cuantificado los niveles de concentración para plomo y cinc en las rías donde se encuentran los principales puertos de la costa gallega. Los patrones de distribución de Pb y Zn en el sedimento muestran altos contenidos en el litoral próximo a las áreas de actividad portuaria y astilleros: las concentraciones llegan hasta 140, 160, 160 y 320 mg·kg-1 para Pb y hasta 150, 380, 600 y 1960 mg·kg-1 para Zn en Pontevedra, Coruña, Ferrol y Vigo, respectivamente. En base a sus niveles naturales, establecidos mediante cuatro testigos de sedimento, se han definido sus grados de contaminación mediante factores de enriquecimiento. Consecuentemente, se puede definir entre moderada y considerable la contaminación de Pb y Zn en los puertos de La Coruña y Pontevedra, así como severa en Ferrol y Vigo. En otras zonas de las rías la contaminación normalmente decrece, como suele ocurrir en estuarios y costas de nuestro planeta donde existen puertos o astilleros

Cephalopod paralarvae and upwelling conditions off Galician waters (NW Spain)

A total of 103 cephalopod paralarvae were sampled during June 1995 in Galician waters (NW Spain). Samples were taken with Bongo nets of 300 and 500 m mesh size at 48 sampling stations along 10 transverse transects ranging from 80 to 600 m water depth. Paralarvae of loliginid squid were most abundant (40%). TheRhynchoteuthion paralarvae of ommastrephid squid accounted for 25%, whereas sepiolids comprised 23% of the total sample. Octopods were scarce, at only 6.6%. Other cephalopod families accounted for 5%. Sizes of paralarvae ranged from 1.0 to 7.1 mm mantle length. Temperature and salinity distribution showed the presence of an intense upwelling during the survey period. The sampling data obtained before and during the presence of upwelled water off Rias of Pontevedra and Vigo (southern zone) showed that paralarval cephalopod abundance and distribution were closely related to the upwelled Eastern North-Atlantic Central Water (ENACW)

Fluvial contributions of nutrient salts, dissolved trace elements and organic carbon to the sea by pristine temperate rivers (SW Europe)

12 páginas, 5 figuras, 3 tablasA summary of the water characteristics of the rivers Sor, Mera and Landro that drain into the Northern Galician Rias (NW Iberian Peninsula) is presented. The analysis was based on fortnightly monitoring during 2008, for major and minor chemical elements in the dissolved phase (Al, As, Cd, Co, Cu, Fe, Mn, Mo, Ni, Pb, U, V, Zn), nutrients (nitrate, nitrite, ammonium, phosphate, silicate), suspended particulate matter, chlorophyll-a and tracers of water quality chemistry (dissolved inorganic nitrogen and carbon). The data cover rivers not urban, agriculturally or industrially affected. Continental inputs of the material via rivers into the Northern Galician Rias were measured and annual fluxes of the dissolved chemical elements to the rias were calculated. In spite of the high variability in water flow, this study provides a good estimate of the overall amounts of nutrients and dissolved elements discharged to pristine ria systemsThis work is a contribution to the Spanish LOICZ program and was supported by the ‘Spanish Ministry of Science and Technology’ through the CICYT program (INTERESANTE project, ref. CTM2007-62546-C03/MAR). N. Ospina-Alvarez thanks the Spanish National Research Council (CSIC) for their financial support (JAE-Pre contract).Peer reviewe

Prevalence of tide-induced transport over other metal sources in a geologically enriched temperate estuarine zone (NW Iberian Peninsula)

10 páginas, 5 tablas, 4 figurasTide-induced transport, diffuse fluxes and river inputs of arsenic, cobalt, chromium, manganese and nickel were studied in an estuarine zone located at the Ria of Ortigueira in the Galician coast of NW Spain to evaluate comparatively the magnitude of trace-element inputs in the estuarine ecosystem. Short-sediment cores and flooding water were collected at the intertidal area of La-Caleira Inlet in spring and summer 2008 during the first 50 min of tidal inundation. High concentrations of dissolved chromium (up to 23 nM) and nickel (256 nM) were found in waters of the Lourido River during 2008. Chromium (up to 795 mg·kg− 1) and nickel (up to 533 mg·kg− 1) in surface sediments of the study area were also high, pointing to natural geological sources (Cape Ortegal Complex). Fluxes associated with molecular diffusion and tide-induced transport across the sediment–water interface were quantified and compared to the river contribution. Mean fluxes from the Lourido River were 0.03 μmol·m− 2·d− 1 for As, 0.02 μmol·m− 2·d− 1 for Co, 0.43 μmol·m− 2·d− 1 for Cr, 0.72 μmol·m− 2·d− 1 for Mn and 5.98 μmol·m− 2·d− 1 for Ni. Diffusive fluxes were negative which indicates the flow of trace elements towards the sediment − 0.47 ± 0.12 μmol·m− 2·d− 1 for As; − 0.007 ± 0.001 μmol·m− 2·d− 1 for Co; − 0.003 ± 0.009 μmol·m− 2·d− 1 for Cr; − 5.44 ± 1.65 μmol·m− 2·d− 1 for Mn; and − 0.02 ± 0.05 μmol·m− 2·d− 1 for Ni. Tide-induced transport of trace metals was up to four orders of magnitude greater than diffusive fluxes. The contributions of trace elements to the estuarine zone from fluvial and benthic origin were quantified, emphasizing the importance of tide-induced transport in estuarine systemsDr Ospina-Alvarez gratefully acknowledges support by a post-doctoral grant from the AXA Research Fund. The CSIC, under the program JAE-Doc (Junta para la Ampliación de Estudios) co-funded by the Fondo SocialEuropeo(FSE), is greatly acknowledged for the post-doctoral contractto Dr. Santos-Echeandía and pre-doctoral contract to Dr. Ospina-Alvarez. This article is a contribution to the Spanish LOICZ program and was supported by CICYT under the INTERESANTE project (ref.CTM2007-62546-C03/MAR) and the Spanish–Portuguese Action (ref. 2007PT0021) both in cooperation with the project‘ Land–sea exchange of trace metals and its importance for marine phytoplankton in an up- welling coast’(ref. CTM2011-28792-C02)financed by the‘Ministerio de Economía y Competitividad’ of Spain. The authors are also grateful to two anonymous referees for their comments and suggestions, which greatly improved the quality of this paperPeer reviewe

Rare earth elements in coastal sediments of the northern Galician shelf: Influence of geological features

11 páginas, 3 tablas, 4 figurasThe Northern coast of Galicia, NW Iberian Peninsula, exhibits a variety of geological features: Ortegal allochthonous complex, Ollo-de-Sapo autochthonous domain and massifs of Bares, Barqueiro and San-Ciprian. In order to examine the influence of terrestrial lithologies on coastal sediments, 103 samples were collected in the Rias of Ortigueira, Barqueiro and Viveiro, their neighbouring shelf and the estuaries of Mera, Sor and Landro rivers. Aluminium, Fe, Sc, particulate inorganic and organic carbon and rare earth elements (REE) were determined in the 6) near Cape Ortegal and the innermost ria zones. The ratio between light and heavy REE (L/H) showed lower values (4–11) around Cape Ortegal and the shelf while higher ratios (15–23) were detected in west of the Cape Estaca-de-Bares and in the inner Viveiro Ria due to elevated contributions of La and Ce. The L/H values normalised to ES reflects the importance of HREE in the adjacent area to Ortegal Complex (LN/HN1.4) in the inner estuaries and west Cape Estaca-de-Bares. The highest REE individual ES normalised were measured in fine-grained sediments of the Mera and Sor estuaries. Sediments from the eastern shelf of Cape Ortegal presented enhanced ratios only for HREE. These results indicate that distribution of REE in the northern Galician region is highly depending on the neighbouring lithological pattern, contrasting with the situation found in the western Galician shelf and the Bay of Biscay. Lanthanides can, thus, provide a useful tool to follow the sediment pathway in the land–sea boundary zones, denoting continental geochemical imprint or fluvial outputs accordingly to the existing hydrological and geological conditionsCICYT project ‘Influence of meteorological forcing, land geochemistry and estuarine zone in the hydrodynamic, biogeochemical cycle of trace metal and rare earth and plankton transport in the Northern Galician Rias (NW Spain)’, ref. CTM2007-62546-C03/MAR, in cooperation with the Spanish–Portuguese Action ref. 2007PT0021Peer reviewe

Hydrography of the Pontevedra Ria: Intra-annual spatial and temporal variability in a Galician coastal system (NW Spain)

In order to ameliorate the dearth of existing scientific knowledge concerning the hydrography of the Pontevedra Ria, a systematic investigation was carried out between October 1997-98. Salinity variations were closely related to river discharge whereas bottom waters presented oceanic characteristics over the whole year. Current was controlled by tide, river discharge, and wind in the internal ria where the highest velocities were directed along the ria channel with a low transverse component. Favorable atmospheric conditions in spring induced coastal upwelling up the continental shelf. In May the upwelling was sufficiently strong to be detected in the inner ria and intensified in July and August, cooling the ria water to 12 degrees -14 degreesC. Upwelling ceased in September, and from November to March seawater transported by the poleward current (35.9; 15 degreesC) was detected on the shelf. From January until March, unanticipated favorable upwelling conditions provoked an influx of poleward inside the ria. Ria intrusion of poleward water and association with occasional winter upwelling conditions has not been observed previously. Isopycnic three-dimensional (3-D) surface and 2-D isopycnal maps show that with high river runoff or intense upwelling, lower-salinity water leaves the ria near the northern margin in the surface layer. Under negative upwelling conditions, the water is partially dammed inside the ria and exits the ria when the wind speed falls. During upwelling events, ENACW penetrated the ria, especially near the southern shore. Arrival of ENACW at the northern entrance impedes the outward water flow through this mouth

The influence of summer upwelling at the western boundary of the Cantabrian coast

7 páginas, 1 tabla, 4 figurasRecent characterizations of atmospheric conditions favorable to upwelling events in the Western Cantabrian Sea have stressed the need to analyze the significance of the orientation of the coast on the phenomenon of upwelling. Surface-wind fields for the northwestern Galician marine area were provided by the QuikSCAT satellite and an SST map was elaborated using the NASA GHRSST satellite data. A cruise was conducted aboard the RV Lura in June 2009 during northern prevailing winds. Data of thermohaline variables, concentration of dissolved oxygen, dissolved inorganic nitrogen, chlorophyll, dissolved and particulate organic carbon and nitrogen and phytoplankton abundances were obtained. When the upwelling developed west of the Cape Ortegal was strong, the Eastern North Atlantic Central Water mixed with coastal water eastward of the Cape and the upwelled seawater reached the westernmost of the Northern Galician Rias, the Ria of Ortigueira. Incoming seawater was poor in nitrate and chlorophyll concentrations when compared to that of the upwelling events in the Western Galician Rias. The phytoplankton assemblages were typical of summer upwelling blooms in the latter Rias but phytoplankton biomass was lower in the Ria of Ortigueira and the species were indicatives of initial (inner ria under continental influence) and advanced (outer ria under upwelling inputs) stages of phytoplankton succession. The observed process arose when the upwelling edge-zone reaches a change of coastal orientation as may also occur in other upwelling regions.This work was CICYT-FEDER financed (CTM2007-62546-C03/MAR).Peer reviewe