13 research outputs found
El cañón submarino de Avilés: una primera aproximación a sus características físicas y a sus comunidades bentónicas
Anthropic resource exploitation and use of the territory at the onset of social complexity in the Neolithic-Chalcolithic Western Pyrenees: a multi-isotope approach
Carbon (δ13C) and nitrogen (δ15N) stable isotope analyses from bone collagen provide information about the dietary protein input, while strontium isotopes (87Sr/86Sr) from tooth enamel give us data about provenance and potential territorial mobility of past populations. To date, isotopic results on the prehistory of the Western Pyrenees are scarce. In this article, we report human and faunal values of the mentioned isotopes from the Early-Middle Neolithic site of Fuente Hoz (Anuntzeta) and the Late Neolithic/Early Chalcolithic site of Kurtzebide (Letona, Zigoitia). The main objectives of this work are to analyze the dietary and territorial mobility patterns of these populations. Furthermore, as an additional aim, we will try to discuss social ranking based on the isotope data and existing literature on this topic in the region of study. Our results show that, based on the bioavailable Sr values, both purported local and non-local humans were buried together at the sites. Additionally, they suggest similar resource consumption based on C3 terrestrial resources (i.e. ovicaprids, bovids, and suids) as the main part of the protein input. Overall, this study sheds light on how individuals from different backgrounds were still buried together and shared the same dietary lifestyle at a time in the Prehistory of Iberia when social complexities started to appear
Caracterización ecológica del área marina del banco de Galicia
Se integra información hidrográfica, geomorfológica, sedimentológica, biológica, sobre hábitats marinos y pesquera, para establecer las bases ecológicas necesarias para la protección y conservación del banco de GaliciaEl banco de Galicia es un monte submarino profundo situado a 180 km de la costa gallega, con una cima situada entre los 650 y los 1.500 m de profundidad y rodeado de zonas abisales de más de 4.000 m de profundidad. El relieve de las montañas submarinas interactúa con la circulación oceánica modificando las condiciones de oligotrofismo imperantes en el mar profundo. El cambio de dirección de las corrientes marinas, al chocar con el banco, produce las llamadas columnas de Taylor que tienen como consecuencia giros sobre la cima y finalmente un enriquecimiento de las aguas que bañan el banco, lo que influye, a través de la cadena trófica, en las especies de cetáceos, aves y tortugas. Estas condiciones, junto al aislamiento de estos bancos, convierten a estos bancos en puntos calientes de biodiversidad. Esta teoría se ha visto corroborada por los estudios realizados en el proyecto INDEMARES, basados en dos campañas de investigación, dónde se ha encontrado una elevada biodiversidad y la presencia de hábitats vulnerables.
El banco de Galicia está bañado por tres capas diferentes: la masa de agua central del Atlántico nordeste europeo (East North Atlantic Central Water: ENACW), por debajo de las aguas superficiales y hasta los 500-600 m; la masa de agua mediterránea (Mediterranean Outflow Water: MOW) y la masa de agua del Labrador (Labrador Sea Water: LSW), que es la capa más profunda.
En cuanto al tipo de fondo, se encuentra roca en el área del flanco oriental y hacia el sureste y en los montes adyacentes como el Rucabado, distinguiendo claramente dos tipos en cuanto a la pendiente, correspondiendo con la roca plana de la cima y la roca en pendiente del borde del banco y paredes. En la cima se encuentran fondos de arenas medias, de reflectividad media y baja según el espesor de sedimento, y arenas finas en los fondos sedimentaruios de los flancos, a profundidades mayores de 1.500.
En el banco se han identificado hasta el momento 793 especies, con taxones que superan las 100 especies como son moluscos, peces (con especial énfasis en los elasmobranquios), crustáceos y cnidarios. Este inventario incluye especies nuevas para la ciencia, primeras citas para aguas españolas y europeas y especies de gran interés científico y biogeográfico. Este último punto se explica por la situación del Banco entre regiones biogeográficas conectadas por corrientes y masas de agua.
El estudio de las conexiones tróficas entre este elevado número de especies ha mostrado el reforzamiento de las rutas bentopelágicas (gambas y macrozooplancton) frente a las dietas epi- y endobentónicas más habituales en otros fondos equivalentes.
Mediante técnicas de muestreo extractivas (arrastres, dragas) y de vídeo, y su proyección sobre la interpretación geomorfológica realizada a partir de la sonda multihaz, se ha obtenido una estimación de la distribución de los hábitats bentónicos del banco. Los hábitats identificados en fondos sedimentarios son 1) arenas medias con ofiuras Ophiacantidae y Flabellum chunii, 2) arenas medias con arrecife de corales profundos de Lophelia pertusa y/o Madrepora oculata, y 3) arenas finas con holoturias elasipódidas (Benthogone rosea). En fondos rocosos se han caracterizado los hábitats de 4) roca batial sin pendiente con gorgonias y corales negros, 5) roca batial de talud con comunidades de corales y esponjas, 6) roca batial de talud con corales blancos, bambú y negros, gorgonias y esponjas, 7) arrecife de corales profundos de Lophelia pertusa y/o Madrepora oculata y 8) roca con nódulos manganésicos.
El único tipo de hábitat de la DH descrito en la zona es el 1.170 (arrecifes). Sólo se han incluido en la Directiva Hábitats como 1.170 aquellos que presentaban una densidad y diversidad suficientes para cumplir la definición de “arrecifes”. De los hábitats descritos en el banco (ver características ecológicas y biológicas más arriba) solo se han incluido en el 1.170 los arrecifes de corales blancos situados en las arenas medias de la cima del banco, los arrecifes de corales blancos de aguas frías de las especies Lophelia pertusa y Madrepora oculata sobre la roca de la cima del monte Rucabado, las comunidades de roca batial de talud de la ladera sur del banco constituidas por colonias de corales blancos de aguas frías de las especies Lophelia pertusa y Madrepora oculata, y una fauna acompañante muy diversa de escleractinias solitarias, corales bambú, corales negros, gorgonias y esponjas de gran porte, y el resto de zonas de roca batial de talud con comunidades de corales y esponjas. Muchos de los hábitats pueden ser incluidos en los listados de hábitat vulnerables de OSPAR, en los tipos jardines de coral, agregaciones de esponjas de profundidad, arrecifes de Lophelia y montículos carbonatados.
En cuanto a las especies de interés para la protección, de las citadas en el banco, el delfín mular (Tursiops truncatus) y la tortuga boba (Caretta caretta) son las únicas especies que figuran en el Anexo II de la Directiva de Hábitats. Sin embargo, muchas epecies de elasmobranquis y algunos peces óseos son consideradas vulnerables, amenazadas o en declive según los criterios definidos por OSPAR y la lista roja de especies amenazadas de IUCN. Algunas de están protegidas por el reglamento europeo 1262/2012 que regula la pesca de especies profundas.
La lejanía del banco respecto a los principales focos de presión y la ausencia casi total de presión pesquera hace que el grado de conservación sea muy alto, pudiéndose hablar de un ecosistema prácticamente prístino. Las recomendaciones para la gestión de esta zona van encaminadas a garantizar esta calidad ambiental actual.Instituto Español de Oceanografía, Comisión Europea Programa LIFE+, Fundación Biodiversida
New records of deep-sea anthozoans (Cnidaria) for the Bay of Biscay (northeastern Atlantic), collected during ECOMARG, INDEMARES and INTEMARES expeditions
Scleractinia (Cnidaria: Anthozoa) from INDEMARES 2010–2012 expeditions to the Avilés Canyon System (Bay of Biscay, Spain, northeast Atlantic)
Twenty-eight species of scleractinian corals
were collected between 55 and 2,291 m depth during INDEMARES 2010–2012 expeditions to the Avile´s Canyon
System and the near continental shelf (Bay of Biscay).
Most interesting species are described and all depicted. All
species were already known from the northeast Atlantic,
although some are seldom reported. Deltocyathus eccentricus and Flabellum chunii are northernmost records in the
eastern Atlantic, and species first collected from the Bay of
Biscay. From a literature review and new records given
herein, 31 species of Scleractinia are known from the
Avile´s Canyon System. Live specimens of six species were
recorded outside their previously known bathymetric ranges in the Bay of Biscay and nearby areas, either at shallower depths (Caryophyllia sarsiae, Monomyces pygmaea,
Stephanocyathus nobilis), or deeper depths (C. atlantica, C.
sarsiae, Enallopsammia rostrata, Solenosmilia variabilis).
Desmophyllum cristagalli has the widest bathymetric range
(551–2,291 m), and Lophelia pertusa is the most widely
distributed species (24 stations). Tabulating the number of
live species occurring in each 100-m depth interval of the
canyon system, highest species richness occurs in the
700–800-, 800–900-, and 1,400–1,500-m depth intervals
(11 species). The habitat-forming species L. pertusa and
Madrepora oculata were abundant in some stations
building well-developed coral banks. Live colonies of the
big-sized species S. variabilis and E. rostrata co-occurred
at the deepest station sampled that yielded scleractinia
(2,291 m)
Semi-automatic method of fan surface assessment to achieve gorgonian population structure in le Danois Bank, Cantabrian Sea
This study presents a semi-automatic method to estimate fan surface of a Placogorgia sp. octocoral assemblage using 3D point
clouds in El Cachucho MPA at 550 m of depth. The presence of gorgonian forests and deep-sea sponge aggregations in Le Danois
Bank was the cause of its declaration as ‘El Cachucho’ Marine Protected Area (MPA), being included in the Natura 2000 network.
The Placogorgia sp. is a structuring species of the deep Cantabrian Sea; parameters such as population structure and morphology
inform on the overall health of this vulnerable habitat, but the estimation of gorgonian metrics often requires destructive sampling.
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. This study proposes a semi-automatic methodology
to assess gorgonian morphometries fitting planes to colonies. Video transects acquired in Le Danois Bank, during the ECOMARG2017 survey using the Politolana underwater towed vehicle were used. Using Pix4D Mapper Pro and Cloud Compare software, size
and morphometry of fan-shaped gorgonians and forest population structure were assessed. RMS of fitting planes shows that the
geometrical figure chosen is suitable to retain the morphometric characteristics of the specimens of this species. The adjustment of
semi-automatic values with a sample of digitized surfaces manually is validated (R2=0.97). The results show that gorgonian
population was mostly dominated by small colonies. The population structure distribution shows a high proportion (~22%) of
recruits (< 0.05 m2
) of fan surface
Semi-automatic method of fan surface assessment to achieve gorgonian population structure in le Danois Bank, Cantabrian Sea
This study presents a semi-automatic method to estimate fan surface of a
Placogorgia sp. octocoral assemblage using 3D point clouds in El Cachucho
MPA at 550 m of depth.
The semi-automatic methodology uses fitting planes to assess colonies
morphometries. Using Pix4D Mapper Pro and Cloud Compare software, size
and morphometry of fan-shaped gorgonians and forest population structure were
assessed. RMS of fitting planes shows that the geometrical figure chosen is
suitable to retain the morphometric characteristics of the specimens of this
species.
The adjustment of semi-automatic values with a sample of manually digitized
surfaces is validated (R2=0.97). The results show that gorgonian population was
mostly dominated by small colonies. The population structure distribution
shows a high proportion (~22%) of recruits (< 0.05 m2
) of fan surface
Analysis of the population structure of a gorgonian forest (Placogorgia sp.) using a photogrammetric 3D modeling approach at Le Danois Bank, Cantabrian Sea
The presence of gorgonian forests and deep-sea sponge aggregations in the Le Danois Bank promoted its declaration as the “El Cachucho” Marine Protected Area (MPA) by the Spanish Ministry of Environment, and its inclusion in the Natura 2000 network. Both habitats are considered vulnerable, so follow-up surveys are being performed to monitor their conservation in compliance with the EU Habitats Directive. The use of a non-invasive methodology, which does not cause damage or alterations on benthic communities, is particularly necessary in vulnerable ecosystem studies and MPA monitoring.
This study analyzed the assemblage structure of a Placogorgia sp. population using a 3D photogrammetry-based method. The study was carried out through the analysis of the video transects obtained at the Le Danois Bank, using the Politolana underwater towed vehicle during the July 2017 ECOMARG survey. Recent developments in specific software of photogrammetric image analysis allowed extracting valuable information from these video transects. Using the Pix4D Mapper Pro software, 3D point clouds were obtained, and the size and morphometry of yellow fan-shaped gorgonian population structure could be evaluated. Due to gorgonian's high structural complexity, the use of length (i.e. height) as the morphometric descriptor of the real size of the colonies is not appropriate. Instead of length, the fan surface area covered by each gorgonian colony was selected as a suitable parameter of size. The direct measurement of this parameter was possible through a complete 3D reconstruction of the gorgonian forest.
A total of 426 colonies of Placogorgia sp. were digitalized to obtain surface measurements and fan spread orientation calculations in 3D models. The results show that gorgonian populations were mostly composed of a high proportion of small colonies (0–0.10 m2). The population structure distribution shows a high proportion (~27%) of recruits (0.5 m2). In 78% of the gorgonian colonies, facing angles were grouped inside the first quadrant (0°-90°), in accordance with the main current direction in this zone. Colony distribution and fan orientation inside the gorgonian forest can be used as data sources to improve monitoring and management programs of these unique habitats in MPAs
An integrated morphological–molecular approach reveals new insights on the systematics of the octocoral Telestula humilis (Thomson, 1927) (Octocorallia : Alcyonacea : Clavulariidae)
Telestula humilis (Thomson, 1927) is a rare deep-sea stoloniferan octocoral distributed in the eastern Atlantic. Here we compared seven putative colonies of this species collected off Spain with the lectotype from the Oceanographic Museum of Monaco and found them to be identical morphologically. Phylogenetic analyses on both full mitogenomes and a concatenated alignment containing two mtDNA genes (mtMutS and Cox1) and nuclear 28S rRNA gene recovered Telestula humilis sister to Incrustatus and Inconstantia rather than to other species of Telestula. This therefore supports its taxonomic reassignment to Pseudotelestula gen. nov. as Pseudotelestula humilis comb. nov. The taxonomic reassignment is also supported by subtle differences observed between the morphology of the colony and the sclerome of Pseudotelestula humilis comb. nov. and the two sister genera. The occurrence of an intrusion tissue with sclerites in the basal part of the gastric cavity of the adult polyps is shared among Telestula and Pseudotelestula gen. nov. However, Pseudotelestula gen. nov. has sclerites arranged in a collaret and points below the tentacles, the sclerites of the calyx wall and the stolon are plump warty spindles, and the intrusion tissue has long sticks and spindles with cone-like spines