BUSCADOR RECOLECTA

Entrevista de radio en el programa "Españoles en la Mar" de Radio Nacional de España relativa a los logros alcanzados en la reproducción del mero en cautividad, 30 de Octubre de 2014

Controlling sex ratios is esential for the aquaculture industry especially in those species with sex dimorfism for relevant poductive traits

Poster XVIII SIEBM, Durante 2010 y 2011 se llevaron a cabo varias campañas multidisciplinares en el Cañón de Avilés y el banco de Galicia para estudiar sus hábitats y especies bajo el proyecto LIFE+ INDEMARES. Concretamente, este trabajo se centró en la macrofauna endobentónica de fondos blandos de esta montaña submarina y del complejo de cañones. Se realizaron muestreos cuantitativos de la macroinfauna bentónica con una draga box corer, tras confirmar la presencia de tipos sedimentarios blandos en las estaciones seleccionadas. Con esta draga de fango se obtuvieron muestras para el estudio faunístico y para el estudio granulométrico. El programa de muestreo en el banco de Galicia comprendió un total de 28 estaciones, entre 683 y 2274 m, mientras que en el Cañón de Avilés se muestrearon un total de 57 estaciones entre 83 y 1881 m. Los resultados de los diferentes análisis granulométricos revelaron que los sedimentos del banco de Galicia están compuestos principalmente por arenas medias con bajo contenido orgánico, en tanto que en el Cañón de Avilés el tamaño de grano decreció con la profundidad, desde arenas muy gruesas hasta fango. A nivel faunístico, en el banco de Galicia se observaron menores valores de abundancia y de diversidad (abundancia media por estación: 554 ind/m2, rango: 67-1478 ind/m2; 182 especies, rango: 6-49 especies; diversidad: 2.5-5.1) que en el Cañón de Avilés (abundancia media por estación: 994 ind/m2, rango: 544-2811 ind/m2; 505 especies, rango: 29-81 especies; diversidad: 4.5-5.8). Los poliquetos fueron el grupo faunístico dominante en ambas zonas, tanto en abundancia como en número de especies. Concretamente en el banco de Galicia los poliquetos fueron seguidos en abundancia por los moluscos, equinodermos, crustáceos y el grupo Otros, mientras que en el cañón de Avilés a los poliquetos le siguieron los crustáceos, moluscos, equinodermos, y el grupo Otros. Once familias registraron más del 50% de los individuos en la montaña submarina: los poliquetos Spionidae, Syllidae, Ampharetidae, Poecilochaetidae, Cirratulidae, Paraonidae, Glyceridae y Sabeliidae, los bivalvos Limopsidae y Thyasiridae, y las ofiuras Ophiacanthidae. En el cañón de Avilés fueron trece las familias que alcanzaron más del 50% de dominancia: los poliquetos Spionidae, Paraonidae, Ampharetidae, Sabellidae, Capitellidae, Syllidae, Maldanidae, Onuphidae y Cirratulidae, los bivalvos Bivalvia spp. y Thyasiridae, los nermetinos, y los equinoideos. A nivel específico, las especies más abundantes del banco de Galicia fueron los poliquetos Aurospio dibranchiata, Poecilochaetus sp., Glycera lapidum y Palposyllis prosostoma, junto con los bivalvos Limopsis cristata y Thyasira succisa, mientras que en el cañón de Avilés las especies dominantes fueron los poliquetos Pterolysippe vanelli y Levinsenia flava, los nemertinos, los bivalvos (Bivalvia indet.), los equinoideos (Echinoidea indet.) y el sipuncúlido Onchnesoma steenstrupii steenstrupii. A nivel de comunidades, en el Banco de Galicia los análisis multivariantes distinguieron claramente las estaciones más someras de arenas medias, de las estaciones más profundas de arenas finas, siendo la profundidad, el contenido en fango y el tamaño medio de grano los principales factores que estructuraron las comunidades bentónicas asentadas. En el Cañón de Avilés se determinaron también varios grupos de estaciones en las que se distinguían las estaciones someras con altos contenidos en arenas gruesas, las estaciones de profundidad intermedia con altos contenidos en arenas finas, y las estaciones profundas con las granulometrías más finas, siendo la profundidad, el contenido en arena fina y el contenido en fango los factores estructurantes más importantes.

En este episodio hablamos de uno de los primeros proyectos de Obsevadores del Mar: Crustáceos Decápodos. Sandra Espeja conversa sobre estos animales con David Díaz, investigador en el IEO y coordinador científico del proyecto; Lluc García, naturalista y cofundador del Museo Balear de Ciencias Naturales; e Iván Ramos, jefe del Servicio de Protección de Especies de la Conselleria de Medi ambient i Territori de Baleares.

The deep-water sedimentary processes and morphological features offshore Madeira Island, located in the Central-NE Atlantic have been scantly studied. The analysis of new multibeam bathymetry, echo-sounder profiles and few multichannel seismic reflection profiles allowed us to identify the main geomorphologies, geomorphic processes and their interplay. Several types of features were identified below 3800 m water depth, shaped mainly by i) the interplay between northward-flowing Antarctic Bottom Water (AABW) and turbidity currents and ii) interaction of the AABW with oceanic reliefs and the Madeira lower slope. Subordinate and localized geomorphic processes consist of tectono-magmatic, slope instability, turbidity currents and fluid migration. The distribution of the morphological features defines three regional geomorphological sectors. Sector 1 represents a deep seafloor with its abyssal hills, basement highs and seamounts inherited from Early Cretaceous seafloor spreading. Sector 2 is exclusively shaped by turbidity current flows that formed channels and associated levees. Sector 3 presents a more complex morphology dominated by widespread depositional and erosional features formed by AABW circulation, and localized mixed contourite system developed by the interplay between the AABW circulation and WNW-ESE-flowing turbidite currents. The interaction of the AABW with abyssal hills, seamounts and basement ridges leads to the formation of several types of contourites: patch drifts, double-crest mounded bodies, and elongated, mounded and separated drifts. The patch drifts formed downstream of abyssal hills defining an previously unknown field of relatively small contourites. We suggest they may be a result of localized vortexes that formed when the AABW’s flow impinges these oceanic reliefs producingthe erosional scours that bound these features. The bottom currents in the area are known to be too weak (1–2 cm s− 1) to produce the patch drifts and scours. Therefore, we suggest that these features could be relics at present, having developed when the AABW was stronger than today, as during glacial/end of glacial stages., SUBVENT

The use of non-invasive methodology, which does not cause damage or alterations on benthic communities, is particularly necessary in vulnerable ecosystem studies and Marine Protected Areas (MPA) monitoring. The European directives on protection and the OSPAR Commission described the habitats structured by sessile species of great size, such as corals or sponges, as particularly vulnerable habitats requiring special protection. The knowledge of population structures as indicators of their state of health is a requirement to improve the management programs. The presence of gorgonian forests and deep-sea sponge aggregations in the Le Danois Bank was the cause of it declaration by the Ministry of the Environment as "El Cachucho” MPA, being included in the Natura 2000 network. Currently being performed follow-up surveys to know their conservation status. This study presents methodology and first results obtained in the analysis of the video transects acquired in ‘El Cachucho’ MPA, during the ESMAREC survey using the ROTV Politolana underwater towed vehicle. Video was recorded to pilot the ROTV, so characteristics of video camera were not specifically designed for monitoring the habitats. But recent developments in specific software of photogrammetric image analysis have allowed extracting valuable information of these video transects. The outputs of the photogrammetric approach include products such as geo-referenced orthomosaic, Digital Surface Model (DSM) and point cloud (XYZ). These data show the possibility to evaluate the size and morphology (including 3D analysis) of the vulnerable species in the area, as the gorgonians Paramuricea placomus and Callogorgia verticillata and the sponges Asconema setubalense and Geodia megastrella. The non-invasive growth rate studies need a set of measurement, fan height, fan width, and others. This methodology will make easier future studies about age and rate of growth of these species and population structure in the zone.

Maitotoxins (MTXs) are among the most potent toxins known. These toxins are produced by epi-benthic dinoflagellates of the genera Gambierdiscus and Fukuyoa and may play a role in causing the symptoms associated with Ciguatera Fish Poisoning. A recent survey revealed that, of the species tested, the newly described species from the Canary Islands, G. excentricus, is one of the most maitotoxic. The goal of the present study was to characterize MTX-related compounds produced by this species. Initially, lysates of cells from two Canary Island G. excentricus strains VGO791 and VGO792 were partially purified by (i) liquid-liquid partitioning between dichloromethane and aqueous methanol followed by (ii) size-exclusion chromatography. Fractions from chromatographic separation were screened for MTX toxicity using both the neuroblastoma neuro-2a (N2a) cytotoxicity and Ca2+ flux functional assays. Fractions containing MTX activity were analyzed using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) to pinpoint potential MTX analogs. Subsequent non-targeted HRMS analysis permitted the identification of a novel MTX analog, maitotoxin-4 (MTX4, accurate mono-isotopic mass of 3292.4860 Da, as free acid form) in the most toxic fractions. HRMS/MS spectra of MTX4 as well as of MTX are presented. In addition, crude methanolic extracts of five other strains of G. excentricus and 37 other strains representing one Fukuyoa species and ten species, one ribotype and one undetermined strain/species of Gambierdiscus were screened for the presence of MTXs using low resolution tandem mass spectrometry (LRMS/MS). This targeted analysis indicated the original maitotoxin (MTX) was only present in one strain (G. australes S080911_1). Putative maitotoxin-2 (p-MTX2) and maitotoxin-3 (p-MTX3) were identified in several other species, but confirmation was not possible because of the lack of reference material. Maitotoxin-4 was detected in all seven strains of G. excentricus examined, independently of their origin (Brazil, Canary Islands and Caribbean), and not detected in any other species. MTX4 may therefore serve as a biomarker for the highly toxic G. excentricus in the Atlantic area.

Presentación oral en el congreso internacional: 14th INTERNATIONAL CORAL REEF SYMPOSIUM, celebrado en Bremen (Alemania) del 19-23 de julio de 2021 (ICRS2021), DETECCIÓN INNOVADORA DE PROLIFERACIONES ALGALES TÓXICAS: UNA NECESIDAD FRENTE AL CALENTAMIENTO GLOBAL, DIANAS