Short spatio-temporal variations in the population dynamics and biology of the deep-water rose shrimp Parapenaeus longirostris (Decapoda: Crustacea) in the western Mediterranean

The deep-water rose shrimp Parapenaeus longirostris is a demersal decapod crustacean that is commercially exploited by trawl fleets. The present work compares its population dynamics, biology and condition in two locations (southern and north-western Mallorca in the Balearic Islands, western Mediterranean, separated by a distance of 120 km) with different environmental conditions and explores the relationships between the species and certain environmental factors. Six multidisciplinary bimonthly surveys were carried out during 2003 and 2004 in these two locations (between 150 and 750 m depth) in order to collect data on the demersal species with bottom trawl, the hydrography (temperature and salinity) with CTD casts, and trophic resources (zooplankton in the water column and suprabenthos with Bongo net and Macer-GIROQ sledge respectively) and sediments with a Shipeck dredge. The trawl fleets from both locations were monitored by monthly on board sampling and daily landings obtained from sales bills. Additional data was obtained from other trawl surveys. Temporal differences were detected both annually, with a decreasing trend over the last years in species abundance, and seasonally, in the biological indexes analysed. Bathymetric differences were also found in abundance, mean length, sex-ratio and condition of females. There were clear differences between the two locations studied, with higher abundance, condition and mean length and a lower length at first maturity for females in the north-western location. Trophic conditions could act as a link between geo-physical and biological changes. These short spatio-temporal differences could be due to the higher productivity found at this location, with higher density of preferred prey for the studied species together with adequate seafloor topography, sediment composition and hydrographical characteristicsPublicado

Condition and recruitment of Aristeus antennatus beyond fishing ground (to depths of 2200 m) in the Mediterranean: relationship with environmental factors

Depth relationships and seasonal trends in the biological condition and recruitment of the red shrimp Aristeus antennatus have been analyzed along down to 2300 m, over all the slope in the Balearic Basin (western Mediterranean). The analysis is based on a composite year (2008-2012 period) and identifies environmental causes of the trends. We found good reproductive and general biological condition of A. antennatus (Gonado-somatic index, GSI) at 800-1300 m in summer (June-July), depths below the fishing grounds. Mating and spawning were at depths below the more saline waters of the Levantine Intermediate water mass. Recruits Smallest juveniles (recruits, ca. 1 yr age) were exclusively distributed below 1000 m, associated with high near-bottom O2 concentration, low turbidity and high C/N in sediments implying favourable trophic conditions. A seasonal migratory pattern is suggested for females, which move shallower to the upper slope during periods of water-mass homogeneity (autumn-winter) to feed in canyons, increasing their energy reserves (hepatic gland weight, HSI). Females move downslope (800-1100 m) to spawn (high GSI) during periods of water mass stratification (late spring-summer). HSI of A. antennatus females decreased linearly with depth down the slope in February and in October-November, i.e., before and after the reproductive period. This nutritional condition of females in these periods is consistent with more consumption of benthic prey (ophiuroids, polychaetes, Calocaris macandreae) at the canyon heads (Cartes, 1994) in late autumn and winter. Our results confirm/suggest: i) how important it is to study the biology of deep-sea species over the whole depth range they inhabit and not only over fishing grounds, and ii) that changes in environmental conditions linked to the progressive warming of Mediterranean Deep Water (WMDW) with a parallel increase of salinity could provoke a decrease of O2 in water masses at below 1000 m, affecting A. antennatus recruitment and its life cycle, which is extensible to other deep-sea specie

Composition and distribution of the larval decapod community in the deep sea of the Western Mediterranean Sea Balearic Sub-basin

Mechanisms facilitating larvae transport from continental to more oceanic areas were investigated in the Balearic sub-basin (BSB), Western Mediterranean Sea. The abundance, distribution, and development stages of decapod larvae were recorded for a transect of 28 stations crossing the central eddy of the BSB. Zooplankton samples were taken to 1,800 m depth by horizontal and oblique 500-μm mesh size nets hauls towed near the benthic boundary (BBL) and in deep scattering layers (DSL). In total, 67 taxa belonging to Decapoda and one Stomatopoda were identified. Advanced development represented 75% of the individuals recorded. 75% of the species corresponded to adults of deep-sea species, 9% were sergestids (mesopelagic species), and the remaining 16% corresponded to shelf and coastal species. Cluster assemblages formed were related to the hydrological conditions, water masses dynamics, and geomorphologic structures mainly associated with nepheloid layers. Advanced and juvenile specimens of commercial species such as Parapenaeus longirostris, Geryon longipes, and Aristeus antennatus were found close to seafloor BBL. The influence of trophic ecology should be considered as the priority factor of larvae concentrations in deep.En prens

Food web functioning of the benthopelagic community in a deep-sea seamount based on diet and stable isotope analyses

14th Deep-Sea Biology Symposium (DSBS), 31 August 2015 - 04 September 2015, AveiroPeer Reviewe

Larvae of the blue crab Callinectes sapidus Rathbun, 1896 (Decapoda: Brachyura: Portunidae) in the Balearic Archipelago (NW Mediterranean Sea)

The invasive blue crab Callinectes sapidus has been frequently recorded during the last years along the NW Mediterranean Sea, leading to established populations. Two megalopae of C. sapidus were found during two different oceanographic surveys in open waters of the Balearic Archipelago, in July 2005 and October 2011, previous to the first reference of adult specimens documented in the Balearic sub-basin. The analyzed environmental conditions of the sampling periods allowed us to hypothesize the likely introduction pathways, namely by maritime transport and surface currents. Furthermore, the recorded megalopae seem to enlarge the life history of C. sapidus in regard to its native area, where spawning peaks occur in late July and early August.Versión del editor

Balearic Islands vs Algeria: two nearby western Mediterranean elasmobranch assemblages with different oceanographic scenarios and fishing histories

In this paper we compare the elasmobranch composition, depth-related trends of species and community descriptors (abundance, biomass, mean fish weight, species richness and diversity) of the Balearic Islands Archipelago and Algeria (north- and southwestern Mediterranean, respectively). The samples used in this study were collected in bottom trawl surveys between 36 and 779 m depth. Generalized linear models, linear regression, cluster and similarity percentage analyses, and generalized additive models were used to compare the two areas. Twenty-nine elasmobranch species were caught, 12 of them common to both areas, 7 appearing only in the Balearic Islands, and 10 only in Algeria. The bathymetric distributions of species were, in most cases, best fitted to uni-modal response curves. The models for species common to both areas showed similar bathymetric trends, except for Etmopterus spinax, which in Algeria showed a maximum abundance lo¬cated 154 m shallower than in the Balearic Islands. Four bathymetric assemblages were identified in both areas with similar depth ranges but with different species composition. The mean values of the community descriptors were higher on the shelf in the Balearic Islands, whereas higher values were detected on the slope in Algeria. Different between-area bathymetric trends for all the descriptors were detected, with the exception of mean fish weight. The distinct environmental scenarios and fishing histories of the areas studied are discussed as underlying traits influencing the elasmobranch populationsPublicado

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

Correction for Lebrato et al., Global variability in seawater Mg:Ca and Sr:Ca ratios in the modern ocean

4 pages, 5 figures.-- Correction Global variability in seawater Mg:Ca and Sr:Ca ratios in the modern ocean; Proceedings of the National Academy of Sciences of the USA 117(36): 22281-22292 (2020); doi: 10.1073/pnas.1918943117; http://hdl.handle.net/10261/221953The authors wish to note the following: “This study’s seawater Sr:Ca values were systematically low as a consequence of normalization to another published low value for the International Association for the Physical Sciences of the Oceans (IAPSO) (1). IAPSO has been used at the Ocean Drilling Program, Texas A&M University (ODP-TAMU) (http://www-odp.tamu.edu/), and is still being used as the primary standard for elemental composition of seawater/interstitial water. Consequently, our seawater value of Sr:Ca = 8.28 mmol:mol was systematically low by approx. 3.70%, if we accept seawater Sr:Ca 8.60 mmol:mol as the recommended value for IAPSO North Atlantic surface water salinity standard. The uncertainty budget should be expanded including the uncertainty of IAPSO composition. The largest contribution to expanded uncertainty of our data comes from the uncertainty of the IAPSO reference composition, which is 3.29% using all published values. This will result in 3.30% (1 SD) expanded uncertainty for seawater Sr:Ca (and 0.5%, for seawater Mg:Ca) of the entire data set with respect to accuracy. We have corrected all seawater Sr:Ca values with a factor of 1.0243 in all our tables (e.g., SI Appendix, Table S1 averages) and in the figures (Fig. 4, Fig. 5), where a ratio was used. Note that the seawater Sr:Ca % changes are small, thus changes are hardly noticeable on large displays (e.g., Figures), but they can be seen in the tables and averages/SD calculations. Seawater Sr:Ca ratios are also corrected in the main text where relevantPeer reviewe

Temporal changes in lipid biomarkers, especially fatty acids, of the deep-sea crustaceans Boreomysis arctica and Nematoscelis megalops: implications of their biological cycle and habitat near the seabed

10 pages, 4 figures, 2 tablesTwo species of benthopelagic deep-water crustaceans, the suprabenthic mysid Boreomysis arctica and the bathypelagic euphausiid Nematoscelis megalops were analysed in their lipidic composition, with especial emphasis on fatty acids, from specimens obtained in the north-west of Mallorca (Balearic Islands, western Mediterranean) at depths ranging between 650 and 780 m. Temporal shifts were studied seasonally, based on five cruises performed in August and November 2003, and February, April and June 2004, using a Macer-GIROQ suprabenthic sledge (0.5 mm mesh size). Evidences of omnivorous and carnivorous feeding habits were found for both species derived from their fatty acid and other lipid profiles. Boreomysis arctica showed a more varied fatty acid profile than N. megalops. This suggests that B. arctica feeds on a wider range of food sources and is a more opportunistic feeder. The high proportions of 16:1(n-7), 20:5(n-3) and 22:6(n-3) fatty acids in both species suggests a link between surface primary production and deep slope habitats, while markers such as 18:1(n-9) and the 20:1(n-9) and 22:1(n-11) fatty alcohols indicate a predatory activity, likely on calanoids. These components may arrive both via phytodetritus deposition to the seabed and by migratory movements of prey consumed by B. arctica and N. megalops close to the sea bottom. Seasonal changes in the total lipids and fatty acid composition of both species are related to the seasonal dynamics in their food sources, coupled with changes in the physiological or developmental stage of individuals. The proportion of total lipids and polyunsaturated fatty acids in the two species may be related to the different life histories of B. arctica and N. megalops. The mysid has direct development of embryos within brood pouches, so eggs with large amount of vitelum are generated and gonad is well developed. By contrast, the meso-bathypelagic euphausiids generate planktotrophic larvae, with a high number of free developmental larvae stages (from nauplius to Furcilia/Calyptopis), and eggs with poor storage of lipid compounds compared with B. arctica embryosThanks to all participants in the cruises IDEA (REN2002-04535-C01-02/MAR), to the crew of the RV ‘Fco. de Paula Navarro’, and to J.L. Lo´pez-Jurado and E. Massutí for on-board assistance. Thanks also to V. Papiol for her laboratory assistance. Special acknowledgements to Dr T. Madurell for her help in the research performing lipid analyses, also to the National Oceanography Centre, Southampton, NOCS/OBE, especially to Dr D. Billett, for the scientific support given to the Marie Curie Fellowship MEIF-CT-2005-010430 co-supervised by the author. Analyses were performed at the University of Liverpool; thanks are extended to the Department of Earth and Ocean Sciences, both to Dr G. Wolff and collaborators for invaluable technical support for lipid analyses. The last three coallegues above mentioned were invited to particpate in the authorship of this articlePeer reviewe

Trophodynamics of the deep-water suprabenthic mysid Boreomysis arctica in the Catalan Sea (western Mediterranean)

10 pages, 4 figures, 3 tablesGut-evacuation rate (R), and daily ration (DR) were studied in the bathyal mysid Boreomysis arctica, a dominant species from the suprabenthic assemblage of the Catalan Sea, during a ca 72 h day-night sampling cycle (Cruise BT1 of March 1994) at depths from 638 to 1256 m. Although the density of B. arctica was higher during daytime in the water column between 0.1 and1.5 m above the sea floor, no significant changes in day-night density were recorded. Feeding peaks were detected during 2 consecutive days in the morning (between 09:59 and 11:58 h), while during the evening and night (between 16:09 and 01:28 h), feeding intensity decreased. The R obtained from field data (Rmax) was 0.114 h-1, whereas the R obtained from experimentally starved specimens collected during Cruise BBC1 of March 1998 varied between 0.141 h-1 (3 specimens) and 0.345 h-1 (1 specimen). The DR calculated with Elliott and Persson model ranged from 13.51 to 15.05% dry wt for R of 0.114 h-1 and R 0.141 h-1, respectively. The DR obtained for B. arctica was higher than the range of DR reported for megafaunal deep-sea decapod crustaceans in the same area (between 0.260 and 4.820% dry wt), but fell within the DR range reported for pelagic zooplankton (euphausiids, hyperiids, calanoids). Adopting 0.6 g C m-2 as the mean annual organic carbon consumption of the sediment community from the neigbouring Lacaze-Duthier canyon (north Catalan Sea), B. arctica would consume ca 3.4% of organic carbon annually. Therefore, the trophic impact of this bathyal species is low compared to its numerical dominance in bathyal assemblages, and is often lower than that reported for mesopelagic speciesThe authors thank the co-participants in the project AMB93/0283 and the crew of the RV ‘García del Cid’ for their helpful assistance during sampling at sea. The project were funded by the CICYT (Comisión Interministerial de Ciencia y Tecnología—Ministry of Research and Science), while the LEA (Laboratorios Europeos Asociados) financed the BBC1 cruisePeer reviewe