Oceanographic Characteristics of the Canary Islands Waters

From the temperature and salinity data obtained in 61 CTD stations from 15 April to 5 May 1988 aboard the Oceanographic/Hydrographic ship TOFINO in the Canary Islands waters, the area oceanographic conditions, thermohaline structure, waters masses and surface geostrophic currents have been determined. Temperature values show an upwelling between the Eastern Islands and the African continent, with a thermic increase towards the West, and a cold water nucleus at SW of La Palma Island. NACW (Northern Atlantic Central Water) is located below the thermodine; there is also a Mediterranean water influence. Depth water masses have not been determined because of the CTO's depth limit of 1000 m. Surface geostrophic currents depicts a flow to the South, corresponding to the Canary Islands current, however the values are numerically small and show evidence of three eddies in both the Eastern and Western regions of the Islands area

Distribution of Planorbulinacea (benthic foraminifera) assemblages in surface sediments on the northern margin of the Gulf of Cadiz

The distributional patterns and related environmental parameters for four species of benthic foraminifera of the Superfamily Planorbulinacea occurring in surface sediments from the northeast Gulf of Cadiz are discussed. Their distribution is related to bathymetry, in the case of Hyalinea balthica (Schröter, 1783), and to the texture of the sediments in the area for the other three, Cibicides refulgens (Montfort, 1808), Lobatula lobatula (Walter and Jacob, 1798) and Planorbulina mediterranensis (d´Orbigny 1826). Two characteristic assemblages were differentiated with Q-mode analysis: F1 (H. balthica), affected mainly by water depth; and F2 (C. refulgens and L. lobatula), related to the substrate, typical of high-energy/low sedimentation rate environments.Se ha determinado el área de distribución de las cuatro especies de foraminíferos bentónicos de la superfamilia Planorbulinacea encontrados en los sedimentos superficiales del margen septentrional del golfo de Cádiz. Su distribución está relacionada, en el caso de Hyalinea balthica (Schröter, 1783), con la batimetría, y las otras tres, Cibicides refulgens (Montfort 1808), Lobatula lobatula (Walter and Jacob, 1798) y Planorbulina mediterranensis (d'Orbigny, 1826) con las características texturales del sedimento. Hay dos asociaciones características: F1 (H. balthica) afectada principalmente por la profundidad en el dominio del agua noratlántica central y F2 (C. refulgens y L. lobatula) relacionada con el substrato, propia de ambientes de alta energía y baja tasa de sedimentación.Instituto Español de Oceanografí

The recent uvigerinids (benthic foraminifera) in the northeastern Gulf of Cadiz

The distributional patterns and related environmental parameters for nine Uvigerina (benthic foraminifera) species occurring in the northeast Gulf of Cadiz are discussed. A new species (Uvigerina pusilla n. sp.) is described. Two assemblages (F1: Uvigerina peregrina and F2: Rectuvigerina phlegeri) are characteristic of the distribution of uvigerinids in this region, related to bathymetry and the mud-sand substrate in North Atlantic Superficial and Central water.Se ha determinado el área de distribución de los uvigerínidos (foraminíferos bentónicos) en el noreste del golfo de Cádiz, donde se han encontrado nueve especies. Su distribución está relacionada con las características texturales y geoquímicas del sedimento. Se ha descrito una especie nueva (Uvigerina pusilla nov. es.). Mediante análisis factorial y regresión multilineal se han diferenciado dos asociaciones, F1 (Uvigerina peregrina) y F2 (Rectuvigerina phlegeri) relacionadas con las características batimétricas y geoquímicas del medio, en la zona de influencia del agua superficial y central noratlántica.Instituto Español de Oceanografí

Miocene sponge assemblages in the face of the Messinian Salinity Crisis—new data from the Atlanto-Mediterranean seaway

The Messinian Salinity Crisis is considered as one of the most influential Cenozoic events that impacted negatively on the benthic fauna of the Mediterranean area. Changing environmental conditions, including a sharp reduction of water exchange between the Mediterranean Sea and the Atlantic Ocean, altered the geographical ranges of many organisms, including sponges (Porifera). Here, we report a unique assemblage of isolated sponge spicules from the upper Miocene of southwestern Spain. The newly recognized sponge fauna was inhabiting the Guadalquivir Basin—the corridor between the Mediterranean and the Atlantic Ocean at that time. It represents a taxonomically rich sponge community that consisted of members of “soft” and “lithistid” demosponges and hexactinellids. Demosponges are represented by at least thirty-four taxa, while hexactinellids are significantly rarer; only six taxa have been identified. From among eighteen taxa recognized to the species level, at least eight seem to be inhabiting this area to these days; six are recorded from adjacent areas, such as the Western Mediterranean, South European Atlantic Shelf, and the Azores, and three are present in the Red Sea and/or the Northern Atlantic. Intriguingly, some taxa seem to have their closest relatives in distant areas, such as the Indo-Pacific and Japanese waters which suggests that the range of some once widely-distributed populations shrunk after the isolation of the Mediterranean and the Messinian Salinity Crisis, surviving to the present day only in refugia.This work was supported by EVAMED (PID2020-118999GB-I00) funded by the Spanish Ministry of Science and Innovation/State Research Agency of Spain (AEI)

Estudio sedimentológico y paleontológico de la zona de los «Freus de Ibiza»

El estudio sedimentológico de los depósitos sublitorales de la zona de los «Freus de Ibiza», entre las islas de Ibiza y Formentera, muestra que se trata de un área constituida por materiales arenosos de composición calcárea (bioclastos), muy ricos en fragmentos de conchas de moluscos y foraminíferos bentónicos, asociados a «praderas de posidonias». Se han podido diferenciar tres «facies franulométricas», según el tamaño medio de grano y grado de selección del sedimento, correspondiendo los materiales más finos y mejor seleccionados a las zonas más cercanas a la costa, y tres «facies paleontológicas, según el contenido en foraminíferos, correspondiendo los máximos contenidos a las áreas de menor profundidad más cerca de la costa, por la acumulación en ellas de los restos procedentes de la zona de «praderas de posidonias», en aguas más profundas, donde normalmente habitan estos organismos.The study of recent sediments beneath the coastline between the island of Ibiza and Formentera («Freus de Ibiza») shows they consist of a chalk-sandy material (bioclastics) and are very rich in phoraminifers associated with «posidonian meadows» and fragments of mollusc's shells. Three types or «facies» of sediments have been classified according to their granulometry, and three paleontologycal facies according to their phoraminifer content, putting the finest chosen ones with a higher percentage of phoraminifers with those found in zones of greather profundity, nearer the coast due to the accumulation of what is left coming out from the deeper part of the zone of «posidonian meadows»

Distribution of Nodosanidae and Epistominidae (benthic foraminifers) assemblages in surface sediments of Cadiz Gulf northern margin

A descriptive study ana distribution area of modern benthic foraminifers of the Families Nodosariidae Ehrenberg, 1838 and Epistominidae Wedexind, 1937, from the surface sediments on the northern Cadiz Gulf have been accomplished, obtaining 6 species of the first and only 1 of the second family. The assemblage is established by means of Q-Mode analysis corresponding to medium», plai

Variacion espacial de las masas de agua en el Estrecho de Gibraltar

Centro de Informacion y Documentacion Cientifica (CINDOC). C/Joaquin Costa, 22. 28002 Madrid. SPAIN / CINDOC - Centro de Informaciòn y Documentaciòn CientìficaSIGLEESSpai