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Effects of artificial diets were tested on growth and digestive gland (DG) lipid composition of juvenile Octopus vulgaris. For Experiment I, three diets were used: (i) SQUID (Loligo gahi) as a control diet; (ii) Squid paste and fish hydrolysate CPSP®, agglutinated with gelatine (GEL20); and (iii) Squid paste, fish hydrolysate CPSP® and gelatine (GEL40). For Experiment II, three diets were used: (i) SQUID, control diet; (ii) Squid paste, CPSP® and alginate (ALG10); and (iii) Squid paste, CPSP® and alginate (ALG20). For both experiments, growth rates for octopuses fed control were higher (P 0.05) between them. All diets promoted similar growth, regardless of the different CPSP® concentrations and binders. Growth rates obtained were among the highest obtained for O. vulgaris with artificial diets until now. The lower growth obtained with the artificial diets was greatly reflected in the DG fatty acid composition. The most important fatty acid groups, such as n-3 highly unsaturated fatty acids, decreased in the DG of animals fed artificial diets. Lipid content, particularly neutral lipids, was higher in the DG of octopuses fed squid, indicating higher nutritional condition of these animals compared to those fed the artificial diets., 2

Living specimens of the amphi-Atlantic asteroid Hacelia superba have been collected in different areas of Gazul mud volcano in the Gulf of Cadiz, south-western Iberian Peninsula, at depths of 380–487 m. This starfish displayed low abundances (~1 ind. 2000 m−2) in beam trawl catches on the mud vulcano and adjacent soft bottoms. The absence of previous records in this area could be due to a low sampling effort on bathyal hard bottoms of the Gulf of Cadiz, especially those of dormant mud volcanoes, as well as a possible misidentification as Hacelia attenuata that also occurs in the area but is restricted to infralittoral and circalitoral bottoms. 0

La realización de dos campañas de adquisición de datos geofísicos del suelo y subsuelo marino en el año 2010, mediante la utilización de técnicas acústicas de muy alta resolución, ha permitido ampliar el conocimiento de dos sectores de la plataforma continental española en el Golfo de Cádiz, comprendidos entre la desembocadura del río Guadalquivir y la Bahía de Cádiz, y entre Cádiz y Chiclana de la Frontera, respectivamente. En el primero se han localizado varias zonas de fracturas que se caracterizan en los perfiles de sísmica de muy alta resolución por fallas normales de alto ángulo y pequeño salto que desplaza claramente las unidades sedimentarias de edad Holoceno, se trata por tanto de fallas que se pueden considerar activas, si bien deben ser el reflejo en superficie de fallas profundas de mayor entidad. Mientras que en el segundo se ha analizado la morfología asociada a la actividad emergente de una estructura diapirica principal. Two oceanographic surveys have been carried out using very high resolution acoustic techniques in 2010. These surveys have allowed us to improve the knowledge of two sectors of the Spanish continental shelf in the Gulf of Cadiz: the first one, from the mouth of the Guadalquivir River to the Bay of Cadiz, and the second one, between Cadiz and Chiclana de la Frontera. In the first sector, we have located several fracture zones which are characterized in the seismic profiles as high angle normal faults of small vertical displacement. These faults displace clearly the Holocene sedimentary units. Therefore, these faults could be considered currently actives, although should be the surface expression of deeper and more significance faults. In the second sector, we have analyzed the associated morphology with the emerging activity of a main diapir

Detail reprocessing and analysis of a multibeam bathymetric data set and seismic profiles have allowed identified several complexes of sedimentary instabilities along the southeastern flank of the Alboran Ridge. A Large Slope Apron System could be defined in this area that includes isolated slides, complex of slides and slope apron systems. These features show different sizes and evolutionary stages. Seismicity and the Quaternary tectonic activity are considered the main factors controlling their development. 0

The geochemical features in surficial sediments on seamounts of the Djibouti Banks allow determining a boundary between two sediment groups which fits with the seamounts summit break. The differences between these groups seem to be related not only with a physiographic limit but also with the influence of bottom currents, external inputs and geochemical processes. 0

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Deep-water Circulation: Processes & Products. International Congress 16-18 june 2010, Baiona, Pontevedra, Spain.-- 2 pages, From a detailed study of multIbeam bathymetry and seismic reflection profiles of high resolution (Sparker) we have studied seabed morphology around the seamounts of the Motril Marginal Shelf, to identify the contouritic features and to reconstruct the sedimentary Influence of bottom-current pathways. These features comprise elongated mounded separated and plastered drifts, moats, scours and terraces whose formation is related to the Intermediate (LIW) and deep water mass (WMDW) dynamics of the Alboran Sea. The seamounts act as topographic barriers and condition the pathways and velocities of the bottom currents which are subdivided in strands around them. Moreover bottom current activity could be induced alternatively by a denser and deepest water mass on cold climatic periods and by a lighter and intermediate water mass in warm interstadials, This is a contribution to projects MONTERA (CTM2009-14157-C02), CONTOURIBER (CTM2008-06399-C04 / MAR) and DEEPER (IEO), and to the RNM-328 and 2009SGR1071 research groups

Seasonally distribution of the lanthanides in the suspended matter and dissolved phasehas been studied during a hydrological year in the estuary of the Odiel River. In his system affected by acid mine drainage take place the coexistence of two water mixture processes; a process salt-induced mixture typical in an estuary and a process of acid water neutralization. In the mixing zone of the estuary there is a removal of the dissolved phase to the suspended matter out of the system. REEs concentrations are controlled by the volume of discharge of the river and degree of neutralization process. Thus, during first rains after a dry period, the gradient in concentration of these elements in the mixing zone ismore pronounced in this system.

The effect of acid drainage on light rare earth elements (LREE) has been studied in the estuarine sediment of the Tinto and Odiel system, where the fluvial and marine water mixing cause an important pH and chlorinity gradient inside. Due to the high influence of pH over the LREE partitioning from dissolved toparticulate phases, an anomalous behaviour has been found on La content in these sediments. Large removal of LREE takes place at low chlorinity zones in unaffected estuaries, but in the studied system this natural process is moved out the outer zones of the estuary. So, the relative La depletion in the estuarine mixing zone is due to the low pH values (< 6) that prevents LREE removal in low chlorinity zones. Once the acid neutralization (pH ~ 7) occurs, some La enrichment can be observed in sediments of the marine estuary.

A sedimentological and geochemical study of 4 cores of the AtlanticMoroccoan margin retrieved during the MVSEIS/08 cruise (R/V Hesperides) has been done. Fourtypes of sediments have been distinguished on the basis of the sedimentological features, organic matter and carbonate content and C/N ratio: a) Organic-rich hemipelagic sediments with C/N close to 8; b) carbonate and organic matter-rich outcropping units with C/N ratios close to 15.5, c) mud breccia units, with low TOC and organic matter values and d) hemipelagic-like units with intermediate geochemical values that are probably related to sedimentary instability.

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We present a morphometric analysis of 41 mounded edifices located on the seafloor to the west of Canary Islands, using a 150 m resolution DEM and very high-resolution seismic profiles. In order to carry out morphometric computation a set of variables (slope, size and shape) were calculated using ArcGIS Analyst tools. A mapping cluster has been generated using Grouping Analyst ArcGIS Statistics toolset where seven differents morphometric groups have been distinguished. Four main types of edifice shapes have been identified within the seven morphometric groups. The first type is a single giant dome elevation that can be considered as an outlier mound. The second type is the most frequent and can be considered as the standard type mound on the Canary continental slope due to its intermediate morphology. They show extrusive seismic characteristics in seismic profiles. The third type is morphologically derived from type 2, representing steeper and higher mounds related with extrusive processes whereas the fourth type represents smoother and flatter mounds related to faulting. This study shows that an elaborated geomorphometry resolves between types of extrusive edifices from those under tectonic conditions Versión del editor

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The mud volcanism in the Iberian and Moroccan margins of the Gulf of Cadiz is well known over more than a decade. Nevertheless, new structures and morphologies related to fluid venting are still discovered in the recent oceanographic cruise SUBVENT2 in 2014 along the Moroccan margin. Four new mud volcanoes have been identified along two sector of Moroccan margin. Two of them in the Eastern Moroccan Margin - EMF (Subvent and Rosco mud volcanoes), located in the upper slope between 350 and 500 m depth. The other two in the Western Moroccan Margin - WMF (Demetrio de Armas and Port Royal), located in the middle slope at 1800 m depth. The main aim of this paper is the morphological characterization of these new mud volcanoes using swath bathymetric data to analyze the relation between tectonic and sedimentary processes with multiparametric sounder and high resolution multichannel seismic profiles. The interpretation of these seismic profiles show that the source of expelled material of mud volcanoes in the EMF is buried under a sedimentary cover of contouritic deposits of 200 m thickness. A high sedimentation rate can cause an increase of pressure that could act as triggered of mud volcano edificies. In the WMF, the new mud volcanoes are developed related to thrust of the Allocthonous Unit of the Gulf of Cadiz. The origin of these structures is mainly related to de NW-SE tectonic compression . Versión del editor

The identification and characterization of a series of complex landslides have been carried out using Topographic Parametric Sounder (TOPAS) very high resolution profiles, obtained during the INDEMARES/CHICA1011 and ARSA0313 cruises, along the upper and middle slope of the eastern Gulf of Cádiz continental margin. These landslides constitute a large area of the Upper Quaternary sedimentary deposits in these physiographic domains and are related to active tectonic and diapiric structures along the Upper Quaternary as well as sea-level fall events. The identification of the stratigraphic units has allowed us to obtain the relative age of these gravitational landslides emplacement during the Upper Quaternary. Versión del editor

Technical advances in hydrographic studies of the seafloor and the progressive use of these techniques in oceanographic expeditions with scientific objectives, is generating greater collaborations between the hydrographic and oceanographic institutions. Coordination between the different institutions and the use of IHO criteria in the acquisition of bathymetric data in oceanographic expeditions, allow regional hydrographic offices to have an additional source of data for the improvement of the navigation charts. Meanwhile the Oceanographic Institutions will benefit by having validated bathymetric data of high precision. This product is of great interest in studies of submarine geological hazards where is necessary to have a very detailed knowledge of the seabed to determine possible morphological changes associated with the risk processes and the possible active structures. In addition, monitoring of active volcanoes need to have a good knowledge of changes in the physico-chemical properties of the water column, the possible changes in low intensity emissions (hot water, gas) can be detected with these studies in the overlying water masses. Versión del editor

Mud volcanism represents an important migration pathway for methane and other gases from deeper reservoirs to the surface; however most submarine sources remain poor quantified. During SUBVENT2 cruise, water column over several mud volcanoes were surveyed for gas seepage characterization. Water samples of ROV Niskin and Rosette-CTD Niskin bottles were recovered above the Bonjardim, El Cid, Las Negras, Mercator, Algacel, Mvseis, Madrid and Yuma mud volcanoes, and at three newly discovered, mud volcano like structures, to quantify overall gases release fluxes from seabed. CO2 and CH4 concentrations were measured by potentiometric titration and using a gas chromatograph, respectively, in order to understand the relationship between physicochemical and geological processes. Gases concentrations decreased from shallower to deeper mud volcanoes. Values varied widely within 50 to 200 nM for CH4 and between 400 to 1500 μatm for fCO2. Greenhouse gases variations were large influenced by water column depth, temperature, salinity and possibly by anaerobic oxidation of methane (AOM). Our observations suggest that the emission of methane and carbon dioxide from the mud volcanoes structures studied here may be relevant at the present as a part of the carbon global cycle. Versión del editor

The Madeira Island lower slope has been build-up mostly by along slope-processes associated with mass movement deposits as seen in GEBCO bathymetry, multibeam bathymetry, Parasound echosounder profiles and multichannel seismic reflection profiles. A plastered contourite drift (Madeira Drift) developed on this lower slope, being composed of seismic units D1, D2 and D3. The most probable water mass responsible for its deposition is the Antarctica Bottom Water (AABW). The youngest sediments of seismic units D2 and D3 are affected by gravity-driven processes, probably slumps and debris flows, which moved downslope towards west. Parasound profiles show evidences of such mass movements on present-day seabottom (e.g. diffraction hyperbolae echoes) but also of past-events buried within the contourite sediments. These older debris flows are recognized by semitransparent/transparent acoustic facies and lenticular shape. Versión del editor

Several morphosedimentary signatures produced by the interaction between alongslope and downslope sedimentary processes have been identified in the Pliocene and Quaternary records as well as on the present-day seafloor of the Alboran Sea. The scenarios of interaction move between two-end-members: from bottom currents dominating gravity flows to gravity flows dominating contour currents. In between these extreme cases, the alternation and balancing of both processes can occur; bottom current activity influencing the gravity flows has been also detected. Although interaction occurs in the Spanish and Moroccan margins, it is especially complex and varied on the Spanish margin, with regional and local effects on the turbidite systems. In contrast, the interaction on the Moroccan margin primarily inhibits the formation of canyons and related fan lobe deposits. Versión del editor

Molluscan assemblages from shelf and slope soft bottoms of the Alboran Sea have been sampled with a beam trawl during 2014 and 2015 MEDITS expeditions. A total of 134 spp. of molluscs (shell size > 3 mm) were identified, being gastropods the most diverse and dominant group. Four main depth related assemblages were detected in multivariate analyses and characterized by (1) Turritella communis, Chamelea striatula and Nucula sulcata for the inner shelf, (2) Timoclea ovata, Clelandella miliaris and Neopycnodonte cochlear for the outer shelf, (3) Nassarius ovoideus, Calumbonella suturale and N. sulcata for the upper slope and (4) Abra longicallus, Euspira fusca and Aporrhais serresianus for the middle slope. Species richness and abundance decreased with depth, unlike evenness and Shannon-Wiener diversity which displayed an opposite pattern. A higher spatial variability was detected for the shelf, indicating that more assemblages may occur at this level and further sampling is needed for covering all sedimentary habitat types of the Alboran Sea.

The present study describes the composition, structure and damage caused by mechanized dredges on discarded species from the wedge clam (Donax trunculus Linnaeus 1758) fisheries in the Alboran Sea. Discard samples were collected on board artisanal fishing vessels in 95 commercial hauls performed in Fuengirola and Caleta de Vélez between March 2013 and March 2014. The collected fauna was characterized according to their abundance and biomass, and considering their damage type by using a three-level scale (no damage, intermediate damage and severe damage) defined for the different faunal groups identified. Data was analysed for contrasting variations in the different areas and seasons. A total of 87 species were identified, including Paguridae and Annelida. Molluscs were the best represented faunal group, followed by decapod crustaceans and echinoderms. Other groups did not usually exceed 1% of the total abundance and biomass such as fishes or sipunculids. Most discarded individuals displayed no damage after their capture, promoting therefore a high survival rate. Among the dominant taxa, echinoderms and crustaceans displayed the highest proportion of damaged individuals due to their fragile exoesqueletons, which make them to be highly vulnerable to the physical impact caused by mechanized dredges and the further processing on board.

Beam-trawl samples were collected during the MEDITS survey in 2014. These samples covered the continental shelf and slope bottoms of the north Alboran Sea, including the Alboran Island, between 40 to776 m depth. The decapod crustaceans were identified to species level and quantified (abundance and biomass). Species richness (S), Shannon-Wiener diversity index (H’), evenness (J’) and functional diversity index was calculated after identifying and quantifying all decapods collected in each sample. A total of 84 species have been found, dominating the families Paguridae (14 spp), Inachidae (10 spp) and Pandalidae (8spp) in relation to number of species. The dominant species were Plesionika heterocarpus, Alpheus glaber and Calocaris macandreae, in terms of abundance and P. heterocarpus and Monadeus couchii in relation to biomass. Both depth and nature of the substrate characterized the different decapod assemblages. Functional diversity and J’ showed a positive correlation with depth, unlike abundance and biomass. On the continental shelf assemblages were dominated by a low number of species with high abundances, however those from the upper and middle slope showed higher evenness and a wide variety of functional groups. The Atlantic influence of the Alboran Sea favors the presence of a high number of species with Atlantic affinity.

This study describes the composition and structure of discards of the stripped venus clam (Chamelea gallina) fishery, and the damage caused by mechanized dredges on discarded species in the Alboran Sea. A total of 106 commercial fishing hauls have been analyzed between March 2013 and March 2014. Samples were collected on board artisanal fishing vessels based in Fuengirola and Caleta de Vélez harbours (Málaga). The collected fauna was characterized considering the damage presented by using a three level scale: no damage, intermediate damage and severe damage. Quantitative and qualitative data were analyzed with multivariate methods for contrasting seasonal variability. A total of 98 species were identified, with molluscs being the best-represented taxa (e.g. Acanthocardia tuberculata, Mactra stultorum), followed by decapod crustaceans (e.g. Portumnus latipes, Liocarcinus vernalis) and echinoderms (e.g. Echinocardium cf. mediterraneum, Ophiura ophiura). Most individuals displayed no damage after their capture. Echinoderms displayed the highest proportion of damaged individuals, followed by mollucs and decapod crustaceans. The discard structure and damage on non-target species displayed significant seasonal differences, with the higher proportions of damaged individuals in winter.

The Gulf of Cádiz, located in the NE Atlantic Ocean, between the Iberian Peninsula and northern Africa, contains more than 50 mud volcanoes (MVs). MVs are seafloor edifices that result from the release of mud, brine and hydrocarbon fluids in areas with gas-rich over pressure sediments. These MVs are in different stages of seepage activity, bearing a broad diversity of chemosymbiotic and heterotrophic organisms. Some previous works focussed on the bryozoans from some areas of the Gulf of Cádiz (e.g. López de la Cuadra & García Gómez, 1994, Harmelin & d’Hondt, 1992a, b) however, information on bryozoans colonizing the different substrate types (bioclasts, authigenic carbonates, mud breccias) of MVs is almost nule. During 2010 and 2011 and within the framework of the INDEMARES-CHICA project, 25 samples were collected with beam trawl and benthic dredge at six MVs (Gazul, Almazán, Aveiro, Pipoca, Tarsis and Chica). Forty-five taxa belonging to 26 families and 31 genera were identified. Most taxa (39) was found in a single MV (Gazul) and others in several MVs, including the taxa Adeonellopsis, Palmicellaria, Tessaradoma, Reteporellina, and Schizomavella sp. 2. Several factors may influence the observed bryozoan biodiversity such as the sampling effort and sampling method used, the type and heterogeneity of substrates, and habitats as well as the depth. The identification to species level of the bryozoan material will improve the information on benthic communities of these MVs located in the recently established Site of Community Importance of “Volcanes de fango del Golfo de Cádiz”.

The Alboran Sea displays oceanographic and biogeographical highlighting characteristics that promote one of the most important areas for marine biodiversity of the Mediterranean and European waters. Nevertheless, anthropogenic activities are threatening some coastal habitats that are highly important for species currently threatened or in danger of extinction (e.g. Patella ferruginea, Pinna nobilis). Consequently, new marine protected areas have been recently declared in the northern Alboran Sea in order to preserve species, habitats and ecosystems. The Sites of Community Importance “Calahonda” (Málaga) and “Acantilados y Fondos Marinos de Calahonda- Castell de Ferro” (Granada) contain Mediterranean characteristic habitats (e.g. Posidonia oceanica beds, coralligenous communities) with an important Atlantic faunistic component, as well as with protected species and others that are extremely rare or absent in other European locations. In addition, ecological processes that are representative of the Alboran Sea (e.g. upwellings, high productivity) take place in these areas, supporting the development of local artisanal fisheries.

VIII Simposio sobre el Margen Ibérico Atlántico (MIA15), del 21 al 23 de septiembre de 2015, Málaga.-- 4 pages, 2 figures, The Diego Cao channel is located on the central-north middle slope of the Gulf of Cadiz. It separates the Bartolomeu Dias and Faro sheeted drift plateaus to the north of the Guadalquivir Bank margin uplift. A striking linear series of circular depressions occur parallel to the channel on the Bartolomeu Dias sheeted drift (western channel flank), while a remarkable amphitheater-shaped escarpment affects the channel eastern flank. Their morphological and high- and medium-resolution stratigraphic analysis allows inferring their origin as the result of a complex interplay between oceanographic (bottom currents), mass-wasting and tectonic processes. All features seem to have a common origin, related to an especially active tectonic phase during the Mid-Pleistocene, probably related to adjustments of the deep structural features. Since then, the action of the bottom currents and the local influence of structural processes have shaped the present-day topography. The Diego Cao channel is re-interpreted as a contourite moat associated to a complex mounded, separated drift that includes the circular depressions. They result from contourite deposition over the erosional surface originated by widespread mass-wasting events during the Mid-Pleistocene, This research is part of the projects MONTERA (CTM-14157-C02-02) and MOWER (CTM-2012-395599-C03) funded by the Spanish Ministry of Economy and Competitivity. The research of Marga Garcia has been funded by a Juan de la Cierva and a Talentia Grant (Ref. 267226)

The Diego Cao channel is located on the central-north middle slope of the Gulf of Cadiz. It separates the Bartolomeu Dias and Faro sheeted drift plateaus to the north of the Guadalquivir Bank margin uplift. A striking linear series of circular depressions occur parallel to the channel on the Bartolomeu Dias sheeted drift (western channel flank), while a remarkable amphitheater-shaped escarpment affects the channel eastern flank. Their morphological and high- and medium-resolution stratigraphic analysis allows inferring their origin as the result of a complex interplay between oceanographic (bottom currents), mass-wasting and tectonic processes. All features seem to have a common origin, related to an especially active tectonic phase during the Mid-Pleistocene, probably related to adjustments of the deep structural features. Since then, the action of the bottom currents and the local influence of structural processes have shaped the present-day topography. The Diego Cao channel is re-interpreted as a contourite moat associated to a complex mounded, separated drift that includes the circular depressions. They result from contourite deposition over the erosional surface originated by widespread mass-wasting events during the Mid-Pleistocene. Versión del editor