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This study assesses the stock structure of Atlantic bonito (Sarda sarda) using the mitochondrial control region as a genetic marker. About 615 individuals distributed in seven locations were analyzed. Two of the locations were in the Mediterranean Sea (MD/BIL95) (Spain and Tunis), three in the northeast Atlantic (AT-NE/BIL94B) (Portugal, Tunis, Morocco and Mauritania), and one in the southeast Atlantic (AT-SE/BIL97) (Côte d’Ivoire). All these samples were obtained thanks to the participation of all authors in two Small Tuna Research Programs funded by ICCAT. The analysis of the genetic variability of the sequence of mitochondrial control regions depicts a clear heterogeneity among locations. The shared genetic pool that comprises the locations within the Mediterranean (Spain and Tunis), including also a sample from the northeast Atlantic (Portugal), is clearly different from the African locations (Senegal and Côte d’Ivoire). Moreover, these two African locations are also genetically differentiated between them. Morocco and Mauritania locations seems to be located in an intermediate situation between these two groups of locations. These results can be used to infer a management policy by ICCAT on the fisheries of this species

The Printed Optical Particle Spectrometer (POPS) is an advanced and small low-cost, light-weight, and high-sensitivity optical particle counter (OPC), particularly designed for deployed on unpiloted aerial vehicles (UAVs) and balloon sondes. We report the performance of the POPS against a reference scanning mobility particle sizer (SMPS) and an airborne passive cavity aerosol spectrometer probe (PCASP) while the POPS is operated on the ground and also while operated on a quadcopter drone, a DJI Matrice 200 V2. This is the first such documented test of the performance of a POPS instrument on a UAV. We investigate the root mean square difference (RMSD) and mean absolute difference (MAD) in particle number concentrations (PNCs) when operating on the ground and on the Matrice 200. When windspeeds are less than 2.6 m/s, we find only modest differences in the RMSDs and MADs of 2.4 % and 2.3 % respectively when operating on the ground, and to 5 % and 3 % when operating at 10m altitude. When windspeeds are greater than 2.6 m/s but less than 7.7 m/s the RMSDs and MADs increase to 10.2 % and 7.8 % respectively when operating on the ground, and 26.2 % and 19.1 %, respectively when operating at 10m altitude. No statistical difference in PNCs was detected when operating on the UAV in either ascent or descent. We also find size distributions of aerosols in the accumulation mode (here defined by diameter, d, where 0.1 ≤ d ≤ 1 µm) are relatively consistent between measurements at the surface and measurements at 10m altitude with RMSD and MAD of less than 21.6 % and 15.7 %, respectively. However, the differences between coarse mode (here defined by d > 1 µm) are universally larger than those measured at the surface with a RMSD and MAD approaching 49.5 % and 40.4 %. Our results suggest that the impact of the UAV rotors on the POPS does not unduly affect the performance of the POPS for wind speed less than 2.6 m/s, but when operating under higher wind speed of up to 7.6 m/s, larger discrepancies are noted. In addition to this, it appears that the POPS measures sub-micron aerosol particles more accurately than super-micron aerosol particles when airborne on the UAV. These measurements lay the foundations for determining the magnitude of potential errors that might be introduced into measured aerosol particle size distributions and concentrations owing to the turbulence created by the rotors on the UAV.

This research was partly supported by European Research Council Project constRaining the EffeCts of Aerosols on Precipitation under the European Union’s Horizon 2020 Research and Innovation Program Grant 724602. M.W.C., P.-L.M., and J.M. were supported by the “Enabling Aerosol-cloud interactions at GLobal convection-permitting scalES (EAGLES)” project (74358), funded by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research, Earth System Model Development program. The Pacific Northwest National Laboratory is operated for the U.S. Department of Energy by Battelle Memorial Institute under contract DEAC05-76RL01830. M.Y., M.W.C, D.W.P, and P.S. were supported by the Natural Environment Research Council (UK) project ACRUISE (grant number: NE/S005390/1). V.T. acknowledges support from the Estonian Research Council grant PSG202. M.S.D. was supported in part by NASA headquarters under the NASA Earth and Space Science Fellowship Program, grant number NNX-80NSSC17K0404, and in part by the CIRES Visiting Fellows Program that is funded by the NOAA Cooperative Agreement with CIRES, grant number NA17OAR4320101. A.Sorooshian was supported by ONR grant N00014-21-1-2115 and NASA grant 80NSSC19K0442 in support of ACTIVATE, a NASA Earth Venture Suborbital-3 (EVS-3) investigation funded by NASA’s Earth Science Division and managed through the Earth System Science Pathfinder Program Office. A. Schmidt acknowledges funding from NERC grants NE/S00436X/1 (V-PLUS), NE/T006897/1 (ADVANCE), and NE/P013406/1 (A-CURE). Z.L. is funded by the US National Science Foundation (AGS1837811) and NASA (80NSSC20K0131). A.Possner is funded by the Federal Ministry of Education and Research (BMBF) under the "Make our Planet Great Again - German Research Initiative", grant number 57429624, implemented by the German Academic Exchange Service (DAAD). E.G. was supported by a Royal Society University Research Fellowship (URF/R1/191602). F.G. acknowledges support from The Branco Weiss Fellowship - Society in Science, administered by the ETH Zurich, and from a Veni grant of the Dutch Research Council (NWO). J.Q. acknowledges support from the EU Horizon2020 projects ACACIA (GA 875036) and FORCES (GA 821205). P.S. acknowledges support by the European Research Council (ERC) project constRaining the EffeCts of Aerosols on Precipitation (RECAP) under the European Union’s Horizon 2020 research and innovation program with grant agreement 724602 and from the FORCeS project under the European Union’s Horizon 2020 research program with grant agreement 821205. R.W. acknowledges support from the US National Oceanographic and Atmospheric Administration (NOAA Award NA20OAR4320271). G.F. acknowledges funding from a NOAA Earth’s Radiation Budget grant, NOAA CPO Climate & CI #03-01-07-001. The National Center for Atmospheric Research is funded by the U.S. National Science Foundation. A.Povey is funded as part of the Natural Environment Research Council’s support of the National Centre for Earth Observation, contract number PR140015.

A multiple approach to the growth of Lophius vomerinus is presented for the first time, based on age estimation of 2282 illicia (first dorsal fin ray) sections, length-frequency analyses (SLCA, ELEFAN, Bhattacharya) and corroborated by tracking cohorts. The growth is studied based on the widest time series (2000–2017) and the largest sample analyzed to date. Individuals ranging from 3 to 109 cm, representing the whole range commercially landed, were collected from annual research surveys in Namibian waters. Modification in the age interpretation using illicia is presented, suggesting a new more accurate criterion at early ages. Two main different growth patterns were obtained, being that of the length-frequency analyses faster than from illicia age estimation. Both growth patterns estimated here are faster than those from previous studies. Possible causes of differences among all studies are discussed. The von Bertalanffy growth parameters from illicia age estimation (L∞ = 110, k = 0.08, t0 = - 1.16) are proposed to be used in age-structured models for the annual assessment of this population. Growth pattern provides tracking of cohorts in the abundance-at-age matrix, with high correlation values obtained between the age abundance indices of the same year-class for most of the age groups compared. Greater lengths and ages were found in females, showing a slightly higher growth rate than males in older specimens., Apoyo al National Information and Research Centre (NATMIRC) de Namibia - 2., Namibian Ministry of Fisheries and Marine Resources and the Spanish Agency for International Development Cooperation, NATMIRC-2, SI

In February 2019, seamounts of the Discovery Rise, SE Atlantic (41–45°S, 3°W - 3°E), were explored in support of the application of the Ecosystem Approach to Fisheries Management in the Southeast Atlantic Fisheries Organization (SEAFO) Convention Area. Video records of the seafloor were produced by the Video-Assisted Multisampler System (VAMS) along 15 valid transects conducted in plateau and flank areas of Shannon, Tablemount, Discovery and Heardman seamounts at depths ranging from 394 to 1839 m. Nine benthic seascapes were classified and described based on substrate hardness, texture, slope, physical and biological modifiers as observed in the video images. Predominant water masses were estimated from temperature, salinity and dissolved oxygen vertical profiles obtained by CTD casts in the vicinity of each transect. A total of 366 fishes were seen (total observation time = 25.0 h) and classified in 32 morphotypes, included in 9 orders and 12 families. Most fish morphotypes (14) were included in the Macrouridae family. Family Moridae, on the other hand, included 65.3% of all fish records (239), with two particularly abundant morphotypes: Laemonema sp. (116) and Guttigadus sp. (92). Thirteen cephalopods were observed and classified in five morphotypes; the oegopsid squid Moroteuthopsis ingens was the most abundant of them (6). Despite the taxonomic uncertainties associated with video identifications, the explored region was found to contain a mixture of tropical – subtropical and subantarctic faunas of the Atlantic. Similarities of fauna composition and non-directional beta diversity estimates revealed some degree of seamount identity, but 57.5–61.9% of morphotypes were shared among seamounts (Jaccard = 0.425, Sørensen = 0.381). Fishes and cephalopods were more frequently observed on the shallower plateau areas under the influence of warmer and more oxygenated Antarctic Intermediate Waters. Depth and related factors did not influence richness, but dissimilarities in fauna composition between video transects increased with increasing depth intervals. Spatial habitat heterogeneity may have accounted for the increased beta diversity within seamounts. The most widely explored Tablemount seamount contained the most diverse observed sites, but also a considerable spatial variability likely associated with seascape heterogeneity. In two sites (transects 11 and 14), there were exceptionally high aggregations of the morid cods Laemonema sp., at the shallowest ‘gravely’ site explored (397 m), and Guttigadus sp., at a site of intermediate depth (1020 m) covered mostly by soft sediments. Neither of these species (or congenerics) have been previously classified as ‘seamount-aggregating” species. On the other hand, the Patagonian toothfish (Dissostichus eleginoides) and other commercial species known to aggregate in these seamounts were not found in the explored areas., SI

SUMMARY In this study we present the analysis of the stock structure of Wahoo (Acanthocybium solandri) using the mitochondrial control region as genetic marker. We analyzed 276 individuals distributed in four locations int eh east and west Atlantic. Samples were from: Northeast Atlantic (AT-NE/BIL94B) (Canary Islands, Spain), from Southeast Atlantic (AT-SE/BIL97) (Côte d’Ivoire and Gabon) and Southwest Atlantic (AT-SW/BIL96). Four of individuals from Southwest Atlantic (AT-SW/BIL96) were genetically identified as Scomberomorus cavalla. The genetic comparison of the four locations failed to show genetic differences. This result suggests a single genetic pool of the Wahoo in the whole Atlantic. Based on these results, ICCAT should reconsider their management strategies for this species in the area studied. RÉSUMÉ Dans cette étude, nous présentons l’analyse de la structure du stock de thazard-bâtard (Acanthocybium solandri) en utilisant la région de contrôle de l’ADN mitochondrial comme marqueur génétique. Nous avons analysé 276 spécimens répartis dans quatre zones de l’Atlantique Est et Ouest. Les échantillons provenaient de : l’Atlantique Nord-Est (AT-NE/BIL94B) (îles Canaries, Espagne), l’Atlantique Sud-Est (AT-SE/BIL97) (Côte d’Ivoire et Gabon) et l’Atlantique Sud-Ouest (AT-SW/BIL96). Quatre spécimens provenant de l’Atlantique Sud-Ouest (AT-SW/BIL96) ont été génétiquement identifiés comme Scomberomorus cavalla. La comparaison génétique des quatre zones n’a pas révélé de différences génétiques. Ce résultat donne à penser à un patrimoine génétique du thazard-bâtard dans l’ensemble de l’Atlantique. En se fondant sur ces résultats, l’ICCAT devrait revoir ses stratégies de gestion pour cette espèce dans la zone à l’étude. RESUMEN En este estudio presentamos el análisis de la estructura del stock del peto (Acanthocybium solandri) utilizando la región de control mitocondrial como marcador genético. Hemos analizado 276 ejemplares distribuidos en cuatro localizaciones en el Atlántico este y oeste. Las muestras procedían de: Atlántico nororiental (AT-NE/BIL94B) (islas Canarias, España), del Atlántico suroriental (AT-SE/BIL97) (Côte d'Ivoire y Gabón) y del Atlántico sudoccidental (AT-SW/BIL96). Cuatro de los ejemplares del Atlántico sudoccidental (AT-SW/BIL96) fueron genéticamente identificados como Scomberomorus cavalla. La comparación genética de las cuatro localizaciones no mostraba diferencias genéticas. Este resultado sugiere un único acervo genético del peto en todo el Atlántico. Basándose en estos resultados, ICCAT debería reconsiderar la estrategia de ordenación para esta especie en la zona estudiada.

Made available in DSpace on 2018-11-26T16:56:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-08-15 Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) Surface sediments were collected from Guanabara Bay, at 14 stations distributed in five sectors, over three sampling campaigns. Analyses of metals, grain size fractions and total organic carbon analyses were performed. The geo-accumulation index and the enrichment factor were estimated to assess contamination status based on background values. Additionally, the sediment quality guidelines were applied to evaluate the adverse biological effects. Results show that there was no seasonal variation in sediment quality based on any methodology, and all methods utilized showed that NW sector and HRJ sector were the worst affected and that the NE sector had the best conditions. The sediments of GB are polluted mainly by Cr, Pb and Zn. According to Sigma SEM/AVS, these metals are not available to the biota, although toxicity tests dispute this. Among the various methods employed, those using background values for the area seem to best reflect the local historical contamination. (C) 2016 Elsevier Ltd. All rights reserved. Univ Fed Fluminense, Dept Geoquim, BR-24020150 Niteroi, RJ, Brazil Univ Fed Fluminense, Dept Biol Marinha, BR-24020150 Niteroi, RJ, Brazil Univ Estadual Paulista, Campus Expt Litoral Paulista CLP, BR-11330900 Sao Vicente, SP, Brazil Univ Fed Bahia, Dept Oceanog, BR-40170110 Salvador, BA, Brazil Univ Fed Rio de Janeiro, Dept Quim Analit, BR-21941909 Rio De Janeiro, RJ, Brazil Univ Estadual Paulista, Campus Expt Litoral Paulista CLP, BR-11330900 Sao Vicente, SP, Brazil FAPERJ: E26/111.190/2011

International Ocean Discovery Program (IODP) Expedition 361 drilled six sites on the southeast African margin and in the Indian-Atlantic ocean gateway, southwest Indian Ocean, from 30 January to 31 March 2016. In total, 5175 m of core was recovered, with an average recovery of 102%, during 29.7 days of on-site operations. The sites, situated in the Mozambique Channel at locations directly influenced by discharge from the Zambezi and Limpopo River catchments, the Natal Valley, the Agulhas Plateau, and Cape Basin, were targeted to reconstruct the history of the greater Agulhas Current system over the past ∼5 my. The Agulhas Current is the strongest western boundary current in the Southern Hemisphere, transporting some 70 Sv of warm, saline surface water from the tropical Indian Ocean along the East African margin to the tip of Africa. Exchanges of heat and moisture with the atmosphere influence southern African climates, including individual weather systems such as extratropical cyclone formation in the region and rainfall patterns. Recent ocean model and paleoceanographic data further point at a potential role of the Agulhas Current in controlling the strength and mode of the Atlantic Meridional Overturning Circulation (AMOC) during the Late Pleistocene. Spillage of saline Agulhas water into the South Atlantic stimulates buoyancy anomalies that act as control mechanisms on the basin-wide AMOC, with implications for convective activity in the North Atlantic and global climate change. The main objectives of the expedition were to establish the sensitivity of the Agulhas Current to climatic changes during the Pliocene-Pleistocene, to determine the dynamics of the Indian-Atlantic gateway circulation during this time, to examine the connection of the Agulhas leakage and AMOC, and to address the influence of the Agulhas Current on African terrestrial climates and coincidences with human evolution. Additionally, the expedition set out to fulfill the needs of the Ancillary Project Letter, consisting of high-resolution interstitial water samples that will constrain the temperature and salinity profiles of the ocean during the Last Glacial Maximum. The expedition made major strides toward fulfilling each of these objectives. The recovered sequences allowed generation of complete spliced stratigraphic sections that span from 0 to between ∼0.13 and 7 Ma. This sediment will provide decadal- to millennial-scale climatic records that will allow answering the paleoceanographic and paleoclimatic questions set out in the drilling proposal.

International Ocean Discovery Program (IODP) Expedition 361 drilled six sites on the southeast African margin and in the Indian-Atlantic ocean gateway, southwest Indian Ocean, from 30 January to 31 March 2016. In total, 5175 m of core was recovered, with an average recovery of 102%, during 29.7 days of on-site operations. The sites, situated in the Mozambique Channel at locations directly influenced by discharge from the Zambezi and Limpopo River catchments, the Natal Valley, the Agulhas Plateau, and Cape Basin, were targeted to reconstruct the history of the greater Agulhas Current system over the past ∼5 my. The Agulhas Current is the strongest western boundary current in the Southern Hemisphere, transporting some 70 Sv of warm, saline surface water from the tropical Indian Ocean along the East African margin to the tip of Africa. Exchanges of heat and moisture with the atmosphere influence southern African climates, including individual weather systems such as extratropical cyclone formation in the region and rainfall patterns. Recent ocean model and paleoceanographic data further point at a potential role of the Agulhas Current in controlling the strength and mode of the Atlantic Meridional Overturning Circulation (AMOC) during the Late Pleistocene. Spillage of saline Agulhas water into the South Atlantic stimulates buoyancy anomalies that act as control mechanisms on the basin-wide AMOC, with implications for convective activity in the North Atlantic and global climate change. The main objectives of the expedition were to establish the sensitivity of the Agulhas Current to climatic changes during the Pliocene-Pleistocene, to determine the dynamics of the Indian-Atlantic gateway circulation during this time, to examine the connection of the Agulhas leakage and AMOC, and to address the influence of the Agulhas Current on African terrestrial climates and coincidences with human evolution. Additionally, the expedition set out to fulfill the needs of the Ancillary Project Letter, consisting of high-resolution interstitial water samples that will constrain the temperature and salinity profiles of the ocean during the Last Glacial Maximum. The expedition made major strides toward fulfilling each of these objectives. The recovered sequences allowed generation of complete spliced stratigraphic sections that span from 0 to between ∼0.13 and 7 Ma. This sediment will provide decadal- to millennial-scale climatic records that will allow answering the paleoceanographic and paleoclimatic questions set out in the drilling proposal.

Clouds in the presence of absorbing aerosols result in their apparent darkening, observed at the top of atmosphere (TOA), which is associated with the radiative effects of aerosol absorption. Owing to the large radiative effect and potential impacts on regional climate, above-cloud aerosols have recently been characterized in multiple satellite-based studies. While satellite data are particularly useful in showing the radiative impact of above-cloud aerosols at the TOA, recent literature indicates large uncertainties in satellite retrievals of above-cloud aerosol optical depth (AOD) and single scattering albedo (SSA), which are among the most important parameters in the assessment of associated radiative effects. In this study, we analyze radiative characteristics of clouds in the presence of wildfire smoke using airborne data primarily from NASA's Cloud Absorption Radiometer, collected during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites campaign in Canada during the 2008 summer season. We found a strong positive reflectance (R) gradient in the UV-visible (VIS)-near infrared (NIR) spectrum for clouds embedded in dense smoke, as opposed to an (expected) negative gradient for cloud-free smoke and a flat spectrum for smoke-free cloud cover. Several cases of clouds embedded in thick smoke were found, when the aircraft made circular/spiral measurements, which not only allowed the complete characterization of angular distribution of smoke scattering but also provided the vertical distribution of smoke and clouds (within 0.5-5km). Specifically, the largest darkening by smoke was found in the UV/VIS, with R-0.34m reducing to 0.2 (or 20%), in contrast to 0.8 at NIR wavelengths (e.g., 1.27 mu m). The observed darkening is associated with large AODs (0.5-3.0) and moderately low SSA (0.85-0.93 at 0.53 mu m), resulting in a significantly large instantaneous aerosol forcing efficiency of 25447Wm(-2-1). Our observations of smoke-cloud radiative interactions were found to be physically consistent with theoretical plane-parallel 1-D and Monte Carlo 3-D radiative transfer calculations, capturing the observed gradient across UV-VIS-NIR. Results from this study offer insights into aerosol-cloud radiative interactions and may help in better constraining satellite retrieval algorithms.

The cruise is a contribution to SEAFO resulting from a co-operation between SEAFO, the EAF-Nansen project, and the FAO Deep-sea programme. The aim is to facilitate activities in support of the efforts by RFMOs to meet objectives in relation to the United Nations General Asssembly (UNGA) resolution 61/105 and the associated FAO Guidelines on Bottom Fisheries in the high seas. Furthermore, the southeastern Atlantic ABNJ was selected by the recently initiated GEF-sponsored FAO ABNJ programme (“Common Oceans”) as an area of particular attention, involving the relevant RFMO with competent to regulate bottom fishing in that region is the Southeast Atlantic Fisheries Organization (SEAFO). Despite a shortage of data on the occurrence of ‘vulnerable marine ecosystems’ (VMEs, as defined in the FAO Guidelines), SEAFO has introduced comprehensive measures to protect such ecosystems from significant adverse impacts within the convention area. The convention area consist of agreed limited ‘existing fishing areas’, i.e. areas were fisheries were conducted within a recent reference period, and more extensive ‘new fishing areas’ where this was not the case. Commercial harvesting is essentially restricted to the ‘existing fishing areas’, but further regulated by other measures such as species-specific TACs, gear restrictions and other measures aimed to conserve e.g. sharks. To conduct exploratory fisheries in ‘new fishing areas’ parties need to submit a notification and detailed plan and report to the Organization for approval. SEAFO has furthermore closed 10 subareas of the convention area to all fishing activity, a regulation most recently revised in 2011. Best available bathymetry data were compiled to locate subareas recognised in the FAO guidelines as VME features, essentially primarily seamounts. As fishing is restricted to the upper 2000m of any feature, a map of areas shallower than 2000m was the basis of further selection. In SEAFO such areas are seamounts or seamount complexes of various sizes and shapes. The spatial distribution of VME indicators such as corals and sponges (i.e. as given in FAO guidelines) is not well known in SEAFO, but the benthic and pelagic biogeographical patterns have been described. It was therefore decided to close 10 potential fishing areas that represented the range of features and the major biogeographical zones of the region. Some of these were actual fishing areas; others were either not fished or lightly fished. The end result was the set of ten closures with various shapes and sizes, ranging from single seamounts to rather wider areas comprising several seamounts or mid-Atlantic Ridge segments. While SEAFO took significant steps to ensure conservation of VMEs, the shortage of information on the distribution patterns of VME indicators remains unsatisfactory. Some new data were acquired by recent fishing experiments in existing and new fishing areas, and by Spanish-Namibian research activity on the Valdivia Bank. However, even within the relatively restricted actual fishing areas, the documentation remains scattered and limited. Similarly, the Scientific Committee of SEAFO struggles with data shortage on the fish resources actually harvested in the convention area, primarily Patagonian toothfish, pelagic armourhead, alfonsino, deep-sea red crab, and associated bycatch species. Stock assessments are generally highly uncertain and fully dependant on fisheries-generated data, hence conservation measures implemented by SEAFO remain largely precautionary rather than tuned to good estimates of abundances and productivity. Catches currently remain rather limited, i.e. collectively less than 1000t, but some species are valuable and tend to attract interest from fishing parties that would value not only enhanced opportunities but also management based on more reliable stock assessments. This project thus aims to supplement and extend knowledge and databases on VME indicators as well as fisheries resources and will accordingly conduct targeted investigations in the currently used fishing areas of the convention area, primarily on the Walvis Ridge. In addition, some of the fishing closures will be visited to document presence-absence of VME indicators and describe distribution patterns. New data from these targeted studies will enhance the quality of fish stock assessments and help analyse the appropriateness of VME closures currently implemented solely based on feature characteristics and biogeographical affinity. Main conclusions: VMEs indicators were located in all seamounts prospected but differences in structure and development state were observed. In some seamounts coral rubble, sediment-clogged, mostly dead coral framework and living coral framework were observed from the base to the summit all along the slope. Current system associated to each seamount, depth and probably other depth-dependent environmental factors driven the presence and development of deep-water reefs. Continuous research efforts are needed to increase knowledge about biodiversity and structure. Understanding their dynamics will improve effective management and conservation of this vulnerable ecosystems. FAO, EAF-Nansen project / Deep-sea Norway project

10 páginas, 7 figuras, 2 tablas, The new information reported in this paper is based on five maturing and mature females of the large-tuberculate octopus Graneledone macrotyla. These specimens were caught in bottom trawl surveys ATLANTIS 2009 (February 24 to April 1, 2009) and ATLANTIS 2010 (March 9 to April 5, 2010) carried out off the Argentinean Economic Exclusive Zone. Capture depth ranged from 475 to 921 m and sea bottom temperature between 2.8 and 3.1 °C. Development of the complex ovary, oviducts, and oviducal glands during gonadic maturation is described. The absence of spermathecae in the oviducal glands and the presence of fertilized eggs inside the ovary suggested that fertilization took place within the ovary. Histological techniques showed the presence of four types of oocytes. Maturing oocyte size–frequency distribution was polymodal. Fluorescence reaction showed that atresia occurred in both early and later oocyte maturation stages. Atresia affected 48–55 % of the initial number of oocytes. The maximum observed potential fecundity was estimated at 250–300 eggs. G. macrotyla showed a group-synchronous ovulation pattern, regulative atresia, and a batching spawning pattern with a few egg batches spawned intermittently over an extended period of spawning.

Acrobat document, 2 tables and 7 Figures. 13 pages, At the South-East Atlantic, fisheries resources have been commercially explored by a large international fleet fishing mostly in the Namibian waters. The Spanish and the former Soviet Union have been the predominant distant fleet working at the continental shelf and their activities were managed until 1990 by the International Commission for the South-East Atlantic Fisheries (ICSEAF). Historically, the following countries are known to have been fishing in the current SEAFO Convention Area. Spain, Portugal, Russia, Cyprus, Mauritius, Japan, Korea, Poland, Norway, South Africa and Namibia, but the quality and quantity of data available remain poor (SEAFO, 2008). Thus, the main activities of some of these fleets occur on the continental shelf (EEZ) and sporadically they explored adjacent seamounts, sometime on the route between fishing grounds or as a target activity. This paper intends to stress the importance of bottom fishing footprint as a method to understand the extent of the areas fished up to date in the SEAFO region. For this exercise some available data from the Spanish and Portuguese fleets were used.

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Deep-sea mussels of the genus Bathymodiolus (Bivalvia: Mytilidae) harbor symbiotic bacteria in their gills and are among the dominant invertebrate species at cold seeps and hydrothermal vents. An undescribed Bathymodiolus species was collected at a depth of 3,150 m in a newly discovered cold seep area on the southeast Atlantic margin, close to the Zaire channel. Transmission electron microscopy, comparative 16S rRNA analysis, and fluorescence in situ hybridization indicated that this Bathymodiolus sp. lives in a dual symbiosis with sulfide- and methane-oxidizing bacteria. A distinct distribution pattern of the symbiotic bacteria in the gill epithelium was observed, with the thiotrophic symbiont dominating the apical region and the methanotrophic symbiont more abundant in the basal region of the bacteriocytes. No variations in this distribution pattern or in the relative abundances of the two symbionts were observed in mussels collected from three different mussel beds with methane concentrations ranging from 0.7 to 33.7 μM. The 16S rRNA sequence of the methanotrophic symbiont is most closely related to those of known methanotrophic symbionts from other bathymodiolid mussels. Surprisingly, the thiotrophic Bathymodiolus sp. 16S rRNA sequence does not fall into the monophyletic group of sequences from thiotrophic symbionts of all other Bathymodiolus hosts. While these mussel species all come from vents, this study describes the first thiotrophic sequence from a seep mussel and shows that it is most closely related (99% sequence identity) to an environmental clone sequence obtained from a hydrothermal plume near Japan.

8 pages, 4 figures, 1 table, The diel distribution of epipelagic siphonophores at a station off northern Namibia (18°00′ S 10°30′ E) was studied. This area is characterized by the mixing of surface waters of the Angola Current with the waters of the northernmost Benguela region. During the sampling period, the continuous flow of the Angola Current gave rise to a marked thermocline at ca 30 m depth. In order to study the diel vertical distribution patterns of epipelagic species under these hydrographic conditions, narrow depth horizons in the top 200 m of the water column were sampled repeatedly over a 48 h period. Thirty-four species were collected. Sphaeronectes gracilis and Chelophyes appendiculata predominated. Increasing numbers of species and individuals were observed on the second day of sampling, particularly in the layers above the thermocline. Only a few species showed an upward nocturnal migration that crossed the boundary between 2 water masses. The differences in the depth distributions of the various species were related to 3 distinct phenomena: the existence of 2 separate siphonophore populations associated with each of the 2 water masses; vertical migration by the most abundant species, which were able to cross the thermocline; and differences in patch size for the most epipelagic species. © 1991 Kluwer Academic Publishers

61 pages, 35 figures, 1 appendix, [EN] Thirty cephalopod species taken in the waters of the Benguela Current between 17º30' S and 30°00' S between the 70 and 800-m isobaths and in the Valdivia Bank area (24-26° S, 05-07º E) are fully described, and a key is provided. A description of the bathymetric and hydrographic features of the study area is also presented. The composition of the cephalopod fauna in the area is examined and compared with that in adjoining areas. A greater diversity of species has been found in South African (75) than in Namibian (30) or Angolan (30) waters. Fifteen of the thirty species found off Namibia also occur in South African waters, while a further ten are also present off Angola. The cosmopolitan nature of certain species, e.g., Todaropsis eblanae and Octopus vulgaris, which have been recorded in all three regions, is confirmed, [ES] Se describen 30 especies de cefalópodos, capturados en aguas de la corriente de Benguela entre los paralelos 17º30' S y 30° S y las isobatas de 70 y 800 y en la zona del Banco Valdivia (24°-26° S y 5º-7º E). Se efectúa una descripción batimétrica e hidrográfica del área de estudio. Se analiza la composición faunística de los cefalópodos del área, comparándola con la de zonas adyacentes, encontrándose una mayor abundancia en aguas sudafricanas, 75 especies, que en aguas de Namibia o Angola, 30 especies respectivamente. Quince de las treinta especies de la zona de Namibia aparecen también en el área sudafricana, otras diez son comunes con la zona de Angola. Se patentiza el cosmopolitismo de algunas especies como Todaropsis eblanae, y Octopus vulgaris que han sido capturadas en las tres áreas. Se ha elaborado una clave de los cefalópodos descritos en el presente estudio, así como una detallada descripción de cada una de las especies

International Ocean Discovery Program (IODP) Expedition 361 drilled six sites on the southeast African margin and in the Indian-Atlantic ocean gateway, southwest Indian Ocean, from 30 January to 31 March 2016. In total, 5175 m of core was recovered, with an average recovery of 102%, during 29.7 days of on-site operations. The sites, situated in the Mozambique Channel at locations directly influenced by discharge from the Zambezi and Limpopo River catchments, the Natal Valley, the Agulhas Plateau, and Cape Basin, were targeted to reconstruct the history of the greater Agulhas Current system over the past ∼5 my. The Agulhas Current is the strongest western boundary current in the Southern Hemisphere, transporting some 70 Sv of warm, saline surface water from the tropical Indian Ocean along the East African margin to the tip of Africa. Exchanges of heat and moisture with the atmosphere influence southern African climates, including individual weather systems such as extratropical cyclone formation in the region and rainfall patterns. Recent ocean model and paleoceanographic data further point at a potential role of the Agulhas Current in controlling the strength and mode of the Atlantic Meridional Overturning Circulation (AMOC) during the Late Pleistocene. Spillage of saline Agulhas water into the South Atlantic stimulates buoyancy anomalies that act as control mechanisms on the basin-wide AMOC, with implications for convective activity in the North Atlantic and global climate change. The main objectives of the expedition were to establish the sensitivity of the Agulhas Current to climatic changes during the Pliocene-Pleistocene, to determine the dynamics of the Indian-Atlantic gateway circulation during this time, to examine the connection of the Agulhas leakage and AMOC, and to address the influence of the Agulhas Current on African terrestrial climates and coincidences with human evolution. Additionally, the expedition set out to fulfill the needs of the Ancillary Project Letter, consisting of high-resolution interstitial water samples that will constrain the temperature and salinity profiles of the ocean during the Last Glacial Maximum. The expedition made major strides toward fulfilling each of these objectives. The recovered sequences allowed generation of complete spliced stratigraphic sections that span from 0 to between ∼0.13 and 7 Ma. This sediment will provide decadal- to millennial-scale climatic records that will allow answering the paleoceanographic and paleoclimatic questions set out in the drilling proposal.