ABSTRACT The biodiversity of sponges in environments beyond 50 m is poorly known, as access to this type of environment without specialized technology is difficult. This study aims to understand the biodiversity of the group present on the continental shelf of the south-western area of Isla Fuerte and Alta Guajira. Sponge samples were collected via trawls during exploration sessions in hydrocarbon blocks between 73 and 210 m, which were fixed and taken to the sponge collection of the Museum of Marine Natural History of Colombia (MHNMC, Makuriwa) in 2012. Then, in 2022, these samples were processed and identified in the laboratory using standard methods. A taxonomic list is presented, with 89 taxa belonging to the classes Demospongiae and Homoscleromorpha, which are grouped in 16 orders, 33 families, 51 genera, and 45 species, out of which 10 are new records for the Colombian Caribbean. Only one species was identified for Alta Guajira, which could be attributed to a difference in substrate composition and to the fact that, in the Isla Fuerte sector, due to diapirism and gas emanation events in the continental shelf, there is a greater availability of food, which can support the composition of sessile benthic organisms such as sponges.

RESUMEN La biodiversidad de esponjas en ambientes más allá de los 50 m es poco conocida, ya que el acceso a este tipo de ambientes es difícil si no se cuenta con tecnología especializada. Este estudio pretende conocer la biodiversidad del grupo presente sobre la plataforma continental del área suroccidental de isla Fuerte y alta Guajira. Se recolectaron muestras de esponjas mediante redes de arrastre durante jornadas de exploración de bloques de hidrocarburos entre los 73 y 210 m, las cuales fueron fijadas y llevadas a la colección de esponjas del Museo de Historia Natural Marina de Colombia (MHNMC, Makuriwa) en 2012. Luego, en 2022, estas se procesaron e identificaron en laboratorio empleando métodos estándar. Se presenta un listado taxonómico con 89 taxa pertenecientes a las clases Demospongiae y Homoscleromorpha, agrupados en 16 órdenes, 33 familias, 51 géneros y 45 especies, de las cuales 10 son nuevos registros para el Caribe colombiano. Se identificó una sola especie para la alta Guajira, lo que podría atribuirse a una diferencia en la composición de sustrato y a que, en el sector de isla Fuerte, por eventos de diapirísmo y emanación de gases de la plataforma continental, hay una mayor disponibilidad de alimento, lo que puede solventar la composición de organismos bentónicos sésiles como las esponjas.

Resumen El objetivo del presente estudio fue caracterizar los cambios estacionales en la composición y abundancia del microfitoplancton en la plataforma continental de Bahía, una región con presencia de eventos de surgencia. Se realizaron muestreos semestrales durante los veranos e inviernos de 2017 a 2021 en nueve puntos. El microfitoplancton se muestreó utilizando una red cónica de plancton en arrastres horizontales debajo de la superficie, utilizando un medidor de corriente acoplado a la red, para medir el volumen total de agua filtrada. La temperatura y la salinidad fueron medidas in situ, presentando valores típicos de aguas tropicales. Además, las concentraciones de nutrientes inorgánicos disueltos corroboraron el patrón oligotrófico marino tropical. Se identificaron un total de 144 taxones en la región, siendo los phyla Heterokontophyta y Dinoflagellata los más representativos, como se registra típicamente en las regiones costeras tropicales. La densidad varió de 6,08 × 104 a 3,38 × 108 células L-1, con valores promedio más altos en verano. Aunque las cianobacterias representaron solo el 3,2% de la riqueza de especies en la región, debido a las floraciones de verano de Trichodesmium erythraeum (2018, 2019 y 2021), fue el grupo más abundante a lo largo del estudio. Se observó que los eventos de surgencia no parecen establecer condiciones favorables para cambios estacionales marcados en la composición y abundancia del microfitoplancton. Las floraciones de Trichodesmium erythraeum están estrechamente relacionadas con la fisiología y la capacidad ecológica de esta especie. Con excepción de los períodos de floración, el área de estudio presentó patrones de alta riqueza y diversidad de especies a lo largo de la serie temporal analizada.

Abstract This study aimed to characterize seasonal changes in microphytoplankton composition and abundance on Bahia continental shelf, a region with upwelling events. Semi-annual sampling was conducted during summer and winter from 2017 to 2021 at nine points. Microphytoplankton was sampled using a conical plankton net through horizontal subsurface drags, using a flowmeter coupled to the net, to measure the total volume of filtered water. Temperature and salinity were measured in situ, presenting typical values of tropical waters. In addition, dissolved inorganic nutrient concentration corroborated a tropical marine oligotrophic pattern. A total of 144 taxa were identified in the region, with the phyla Heterokontophyta and Dinoflagellata being the most representative, as is typically recorded in tropical coastal regions. The density ranged from 6.08 × 104 to 3.38 × 108 cells L-1, with higher average values in summer. Although cyanobacteria accounted for only 3.2% of species richness in the region, due to summer blooms of Trichodesmium erythraeum (2018, 2019, and 2021), it was the most abundant group throughout the study. It was observed that upwelling events do not seem to establish favorable conditions for marked seasonal changes in microphytoplankton composition and abundance. Trichodesmium erythraeum blooms are closely related to physiology and ecological capacity of this species. Except for bloom periods, the study area presented a high species richness and diversity throughout the analyzed time series.

ABSTRACT A comprehensive tectono-stratigraphic and sedimentological investigation of Early to Middle Devonian rocks was conducted in the southern Floresta Massif and adjacent regions in the Northern Andes of Colombia. A substantially reduced thickness of the Floresta Formation compared to prior studies is suggested here, attributable to pronounced stratal deformation and the prevalence of recumbent folds throughout the area. The deformation in the Floresta Formation manifests as atypical recumbent folds, diverging from the structural behavior observed in the underlying and overlying strata of the El Tibet and Cuche formations respectively, which exhibit minimal deformation. Our findings also reveal that the Floresta Formation accumulated under shallow-water platform conditions, subject to eustatic sea-level fluctuations. This resulted in distinct episodes of carbonate and siliciclastic deposition, with terrigenous sediments sourced from continental origins, potentially encompassing a combination of cratonic areas and uplifted blocks. The identification of a plausible stage of carbonate silicification signifies a post-diagenetic transformation. The sedimentary rocks of the Floresta Formation reached the upper epizone conditions, in proximity to the transition between the epizone and the upper anchizone, which suggests a maximum depth and temperature of ~5-7 km and ~300 °C, respectively. This contribution provides new insights into the geological history of the region, emphasizing the importance of scrutinizing Early to Middle Devonian rocks within the broader geological context of the Northern Andes.

RESUMEN Este trabajo presenta una exhaustiva investigación tectono-estratigráfica y sedimentológica de las rocas del Devónico temprano a Medio en el sur del Macizo de Floresta y regiones adyacentes, Andes del Norte, Colombia. Se sugiere un espesor sustancialmente reducido para la Formación Floresta en comparación con estudios previos, atribuible a una deformación pronunciada de los estratos y a la prevalencia de pliegues recumbentes en toda el área. La deformación en la Formación Floresta se manifiesta mediante pliegues recumbentes atípicos, a diferencia del comportamiento estructural observado en los estratos subyacentes y sobreyacentes de las formaciones El Tíbet y Cuche, respectivamente, que muestran una deformación mínima. Se revela también que la Formación Floresta se acumuló en condiciones de plataforma de aguas someras, sujeta a fluctuaciones eustáticas del nivel del mar. Esto resultó en variados episodios de depositación carbonática y siliciclástica, con aportes de sedimentos terrígenos provenientes de fuentes continentales, los que posiblemente abarcaron una combinación de áreas cratónicas y bloques levantados. La identificación de una posible etapa de silicificación carbonática indica una transformación postdiagenética. Las rocas sedimentarias de la Formación Floresta alcanzaron las condiciones de la epizona superior, en proximidad a la transición entre la epizona y la anquizona superior, lo cual sugiere una profundidad y temperatura máximas de ~5-7 km y ~300 °C, respectivamente. Esta investigación aporta nueva información acerca de la compleja historia geológica de la región, enfatizando la importancia de examinar las rocas del Devónico Temprano a Medio en el contexto geológico más amplio de los Andes del Norte.

RESUMEN Numerosos autores han interpretado el margen pacífico colombiano como sucesivas acreciones de terrenos oceánicos, con la generación de cuencas de antearco bajo un régimen tectónico compresivo-transpresivo vigente durante el Cretácico tardío-Mioceno. Existe nueva información adquirida en la última década, consistente en nuevas secciones sísmicas y geológicas reprocesadas, además de información de pozos y columnas estratigráficas. En el presente trabajo se analiza esta nueva información y se hace notar que no presenta coherencia con los modelos de sucesivas acreciones de terrenos oceánicos propuestos a la fecha. Los nuevos datos sugieren que, entre el Cretácico tardío y el Eoceno Medio-tardío, las cuencas costa adentro (onshore basins) estuvieron regidas por una extensa plataforma marina, con crecimiento de carbonatos arrecifales hacia el final de ese periodo. Coetáneo a la sedimentación del Cretácico tardío, se presentó magmatismo efusivo, principalmente basáltico. A partir del Oligoceno, la evolución de las cuencas estuvo dominada por procesos diferentes durante tres periodos. Primero, en el Oligoceno-Mioceno temprano, en la cuenca Tumaco y subcuenca San Juan ocurrió un evento transtensional acompañado del emplazamiento de cuerpos ígneos hacia sus bordes orientales, con la generación de estructuras de pilares tectónicos, fosas tectónicas y fallas tipo dominó. En tanto, la subcuenca Atrato presentó hacia su límite sur deformación con fallas inversas locales concentradas en su flanco oriental. Segundo, durante el Mioceno Medio-tardío se levantó el flanco occidental de la cuenca Tumaco, mientras que en la subcuenca San Juan tuvo lugar deformación transpresiva dada por la interacción del sistema de fallas San Juan y Garrapatas. Tercero, durante el Pleistoceno, en la subcuenca Atrato se generó el anticlinal de Baudó asociado a un régimen transpresional. Los resultados aquí expuestos sugieren que no hay evidencia de acreción de terrenos oceánicos en las cuencas estudiadas; tampoco se observan los efectos generados por la presencia de un sistema de subducción durante el Cretácico tardío-Eoceno Medio. Esto abre la posibilidad de que el sistema de subducción en el margen pacífico colombiano haya comenzado en el Oligoceno temprano.

ABSTRACT Several authors have interpreted the Colombian Pacific margin as a succession of oceanic terrane accretions, with generation of forearc basins under a compressive-transpressive tectonic regime during the Late Cretaceous-Miocene. New data acquired in the last decade, consisting of reprocessed seismic lines, geological cross-sections, stratigraphic data from wells, and new stratigraphic columns, are analyzed in this study. We suggest that the proposed models of successive terrane accretions are not supported by the new data; rather, the onshore basins were likely controlled by a marine platform from the Late Cretaceous to the Middle-Late Eocene, with reef growth to the end of this period. In the Late Cretaceous, contemporary to the sedimentation stage, effusive magmatism, mainly basaltic, also occurred. Since Oligocene time, the basins were affected by three different tectonic processes. First, during the Oligocene-Early Miocene, an extensional-transtensional event occurred in the Tumaco Basin and San Juan Sub-basin, which produced horst and graben structures and domino faults, along with the emplacement of igneous bodies in the eastern flank of the basins. The Atrato Sub-basin was affected by local reverse faulting towards its eastern edge. Second, during the Mid-Late Miocene, the western side of the Tumaco Basin was uplifted, and transpressive deformation occurred in the San Juan Sub-basin as evidenced by the San Juan and Garrapatas fault systems. Finally, in the Atrato Sub-basin, a transpressional regime is evidenced by the Baudó anticline. Our results suggest there is no evidence of oceanic terrane accretions in the abovementioned basins during the Late Cretaceous-Middle Eocene. Furthermore, we do not see evidence of a subduction system during that period. We conclude that subduction in western Colombia could have begun during the Early Oligocene instead.

Resumo: Corais invasores do gênero Tubastraea apresentam maturidade precoce, rápido crescimento e plasticidade em relação ao substrato que utilizam, o que permitiu ao gênero obter rapidamente sucesso e expandir sua distribuição não nativa. Para o estado de Sergipe existem 23 registros de Tubastraea spp. na zona offshore; aqui relatamos os primeiros registros do coral-sol T. coccinea na costa da zona estuarina do rio Vaza-Barris, expandindo sua área de invasão offshore para o onshore. Plataformas petrolíferas, navios e naufrágios contaminados podem ter fornecido o caminho como vetores, agindo como trampolins que ligam as regiões oceânicas à costa. A dispersão também pode ocorrer através de correntes responsáveis pelo transporte de organismos da plataforma continental para a costa, embora isto pareça menos provável. Assim, reforçamos a importância do monitoramento constante dos vetores e da costa para minimizar os efeitos adversos dos corais invasores sobre a fauna nativa. Resumo precoce utilizam nativa 2 spp coralsol coral sol T VazaBarris, VazaBarris Vaza Barris, Barris Vaza-Barris onshore petrolíferas provável Assim

Abstract: Invasive corals of the genus Tubastraea exhibit early maturity, rapid growth, and plasticity regarding the substrate they use, which has enabled the genus to quickly become successful and expand its non-native range. For the state of Sergipe there are 23 records of Tubastraea spp. on oil platforms; here we report the first records of the sun coral T. coccinea on the coast in the estuarine zone of the Vaza-Barris River, expanding its invasive range from offshore to onshore. Contaminated oil platforms, vessels, and shipwrecks may have provided a pathway as vectors, acting as stepping stones that connect oceanic regions to the coast. Dispersal may also occur through currents responsible for transporting organisms from the continental shelf to the coast, although this seems unlikely. Thus, we reinforce the importance of constant monitoring of vectors and the coast to minimize the adverse effects of invasive corals on native fauna. Abstract maturity growth use nonnative non 2 spp platforms T VazaBarris Vaza Barris River onshore vessels unlikely Thus fauna

RESUMO Este estudo apresenta uma avaliação inicial das características hidrográficas na região do Cânion do Rio Japaratuba, este cânion fica na plataforma continental de Sergipe, Brasil. Foi realizado uma campanha oceanográfica, durante a campanha oceanográfica foram realizados dois transectos de alta resolução espacial nos lados norte e sul do cânion, juntamente com um transecto transversal. Os resultados indicam que as características hidrográficas são semelhantes às encontradas na plataforma continental de Pernambuco, com a massa de água dominante sendo a Água Tropical. No entanto, difere por ter apresentado uma influência maior da Água Costeira, resultado da dispersão da pluma do Rio São Francisco e de pequenos Rios que desaguam na porção norte da plataforma continental do estado de Sergipe, em direção sul. A turbidez e a clorofila próximo ao fundo, foram relativamente mais altas na seção sul, o que pode ser uma indicação de que a presença do cânion pode produzir um efeito de ressurgência localizado, desempenhando um papel no soerguimento da água do topo da termoclina permanente, para uma região mais próxima da costa. Japaratuba Sergipe Brasil transversal Pernambuco Tropical entanto Costeira fundo localizado permanente costa

ABSTRACT This study presents an initial assessment of the hydrographic characteristics in the region of the Japaratuba Canyon on the continental shelf of Sergipe, Brazil. An oceanographic campaign was conducted, during which two high spatial resolution transects were made on the north and south sides of the canyon, along with a transverse transect. The results indicate that the hydrographic features are similar to those found on the continental shelf of Pernambuco, with the dominant water mass being Tropical Water. However, it differs in having a much greater influence from Coastal Water, as a result of the dispersion of the São Francisco River plume to the south and from small rivers that discharge into the northern portion of the continental shelf of the state of Sergipe. The near bottom turbidity and chlorophyll were relatively higher in the southern section, what can be an indication that the presence of the canyon can produce a localized upwelling effect, with the canyon playing a role in allowing the approach of water from the top of the nearest permanent thermocline to the coast. Sergipe Brazil conducted transect Pernambuco Water However section effect coast

RESUMO Devido à frequente ocorrência de eventos hidrológicos extremos nos regimes de escoamento dos rios da América do Sul, o presente trabalho tem como objetivo o desenvolvimento de uma plataforma de monitoramento hidrológico aberta ao público, com um acesso amplo e intuitivo, utilizando recursos de um sistema de informação geográfica online, com o intuito de contribuir para um melhor entendimento acerca do comportamento desses desastres naturais. A plataforma de acompanhamento hidrológico dos rios da América do Sul (SARDIM - South America River Discharge Monitor) foi construída com auxílio de recursos de programação em linguagens como Python e Javascript. Os dados da plataforma são provenientes de resultados de um modelo de simulação hidrológica de escala continental (MGB - South America) que utiliza, entre outras informações, dados de precipitação da missão GPM (Global Precipitation Measurement) e do produto MSWEP (Multi-Source Weighted Ensemble Precipitation). Após uma análise estatística das informações resultantes do modelo, a plataforma é atualizada diariamente de forma operacional com novos dados de permanência e tempo de retorno das vazões dos rios, permitindo a identificação, o acompanhamento e a avaliação da intensidade de eventos hidrológicos extremos na América do Sul. público intuitivo online naturais SARDIM Monitor Javascript MGB utiliza Global Measurement MultiSource Multi Source Precipitation. . Precipitation) identificação

ABSTRACT Due to the frequent occurrence of extreme hydrological events in the South American rivers, this work aims to develop a hydrological monitoring platform open to the public, with a wide and intuitive access, using resources of an online geographic information system, in order to contribute to a better understanding of the behavior of these natural disasters. SARDIM (South America River DIscharge Monitor) has been developed using programming resources in languages such as Python and JavaScript. The data of the platform are derived from results of a continental scale hydrological simulation model (MGB - South America) that uses, among other information, precipitation data from the GPM (Global Precipitation Measurement) mission and from the MSWEP (Multi-Source Weighted Ensemble Precipitation) product. After a statistical analysis of the model results, the platform is updated daily and operationally, with new data on the flow duration and the return period of river flows, allowing the identification, monitoring and evaluation of the intensity of extreme hydrological events in South America. rivers public access system disasters Monitor JavaScript MGB uses Global Measurement MultiSource Multi Source product operationally flows identification

METALS IN SEDIMENTS FROM THE SHELF-SLOPE INTERFACE OFF THE POTIGUAR BASIN OFFSHORE OIL EXPLORATION AREA, NE BRAZIL. Marine sediments collected in November 2009 and July 2011 at depths ranging from 150 m to 2,000 m in the Potiguar Basin, northeastern Brazil, were analyzed for their main sedimentological characteristics (contents of carbon, nitrogen and their stable isotopes) and metals (Al, Fe, Mn, As, Cr, Cu, Ni, Pb, V and Zn) concentrations and their spatial distribution. Sediments were relatively rich in organic matter (C-org: 0.21% to 0.56%) and metals concentrations increased with depth, suggesting an accumulation of fine and terrigenous sediments eroded and transported from the continental shelf to the slope region. Metals concentrations were higher than those observed in coarser shelf sediments, because of sorting of fine-grained sediments. Iron (Fe), Cr and Cu distribution, although presenting this general pattern, also suggests some changes along the transport. Fe and Cr, probably in discrete minerals, are less affected by accumulation in deeper sediments. The high enrichment in Cu, however, suggests additional sources directly to slope sediments, probably by biological productivity and deposition through the water column. The concentrations of all metals are lower or fall close to the lowest range of concentrations reported for slope sediments from other marine regions worldwide and no evidence of anthropogenic contribution was evident. SHELFSLOPE SHELF SLOPE AREA BRAZIL 200 201 15 2000 2 000 2,00 Basin Brazil contents carbon isotopes Al, Al (Al Mn As Ni Pb Zn distribution Corg C org (C-org 021 0 21 0.21 0.56% 056 56 depth region finegrained grained , (Fe) pattern transport minerals however column evident 20 1 00 2,0 02 0.2 0.56 05 5 (Fe 2, 0. 0.5

SOURCE OR SINK? A REVIEW OF THE CO2 FLUXES AT THE BRAZILIAN CONTINENTAL SHELF. Studies of global carbon balance estimates are still incipient in the oceans of the Southern Hemisphere, mainly in coastal areas and continental shelf. Even in Brazil, despite its continental proportion coastline, there is still a great inconsistency in studies on the marine carbonate system and CO2 fluxes at the air-sea interface. This article presents a review of studies on CO2 fluxes on the coast of Brazil, published between the years 2000 and 2022, aiming to map the distribution of CO2 fluxes on the Brazilian continental shelf, to understand its role as a source or sink of CO2. In general, large-scale studies show that the Brazilian shelf exhibits a latitudinal variation of air-sea CO2 fluxes, behaving mainly as a source in the north, where there is no influence of the Amazon River plume, and as a sink in the south portion. We also identified there is a strong influence on the occurrence of mesoscale and synoptic oceanographic and meteorological events, and the presence of different ecosystems, which can change the behavior of CO2 fluxes locally. However, there are still many data gaps along the continental shelf, as well as in different seasons for the entire coast. SINK CO SHELF Hemisphere Brazil coastline airsea air sea interface 200 2022 general largescale large scale north plume portion events ecosystems locally However 20 202 2

Abstract There are records of seven species of hagfishes in the Argentine shelf and continental slope, comprising the most diverse region for this group in the Southwestern Atlantic. Here, the authors report the occurrence of Myxine affinis and Myxine knappi in San Jorge gulf, adding two species to the ichthyofauna of central Patagonia. A specimen of M. affinis (447 mm TL; hermaphrodite) was incidentally caught by the Patagonian shrimp fishing fleet and collected by the Fishery Observer Program of Fisheries Secretariat of the Chubut Province, Argentina. Subsequently, the authors collected a second specimen of M. affinis (358 mm TL; female) and a specimen of M. knappi (303 mm TL) during the research cruises of the oceanographic vessel ARA Puerto Deseado, within the “Pampa Azul” initiative. The latter is the twelfth record for the species. These specimens are stored in the ichthy ological collection of the Instituto de Investigación de Hidrobiología of the Universidad Nacional de la Patagonia San Juan Bosco, Trelew (UNPSJB-ICT), Argentina. These new records of M. affinis and M. knappi extended their known distribution by 850 km and 220 km northward, respectively. In addition, the authors reported morphomet ric, meristic and reproductive variables of the collected specimens.

Resumen En aguas de la plataforma Argentina y del talud continental se tiene registro de siete especies de mixines (hagfishes), comprendiendo la región de mayor diversidad del Atlántico sudoccidental. A partir del Programa de Observadores a Bordo de la Secretaría de Pesca de la Provincia del Chubut, que monitorea las pesquerías industriales de la región, se capturó incidentalmente un ejemplar de Myxine affinis (447 mm TL; hermafrodita). Posteriormente, durante las campa ñas de investigación del buque oceanográfico ARA Puerto Deseado, en el marco de la iniciativa “Pampa Azul”, se registró un segundo ejemplar de M. affinis (358 mm TL; hembra) y un ejemplar de Myxine knappi de 303 mm TL. Este último es el doceavo registro para la especie. Todos los ejemplares fueron capturados mediante la utilización de redes de arrastre de fondo y se encuentran depositados en la colección ictiológica del Instituto de Investigación de Hidrobiología de la Universidad Nacional de la Patagonia San Juan Bosco, sede Trelew (UNPSJB-ICT), Argentina. Estos nuevos registros amplían la distribución conocida para M. affinis y M. knappi en 850 km y 220 km respectivamente, sumando así dos especies a la ictiofauna de Patagonia central. En los ejemplares colectados, se registraron variables morfométricas, merísticas y reproductivas.

Abstract: The aims of this paper is to analyze the impact of the negotiations for hydrocarbons and the presence of transnational corporations on the Malvinas issue in the framework of Anglo-Argentine relations for the sovereignty of the islands. At the same time, it seeks to describe the repercussions for Argentina in the period 1995-2015. During this stage the sovereignty issue is not discussed, but there were negotiations for hydrocarbons housed in the marine basins of the continental shelf of the islands. These negotiations ended up generating rift between the parties and the arrival of transnational corporations in the area further complicated the situation of the still unresolved dispute.

Resumen: El presente trabajo tiene por objetivo analizar la incidencia de las negociaciones por los hidrocarburos y la presencia de las empresas transnacionales sobre la cuestión Malvinas, en el marco de las relaciones anglo argentinas por la soberanía de las islas. Al mismo tiempo, se busca describir las repercusiones para Argentina en periodo 1995- 2015. Durante esta etapa no se discute el tema soberanía, pero existieron negociaciones por hidrocarburos alojados en las cuencas marinas de la plataforma continental de las islas. Estas tratativas terminaron generando rispideces entre las partes y, la llegada de las empresas transnacionales a la zona complejizó aún más la situación de la controversia que permanece aún irresuelta.

Resumen El objetivo de este estudio fue determinar la distribución, riqueza e identificación molecular de cangrejos araña en las costas Pacífico y Caribe costarricenses. Se realizaron mapas de distribución de especies de la familia Mithracidae en las costas del Caribe y Pacífico de Costa Rica a partir de muestreos exploratorios y registros espacio-temporales de colectas (1960 al 2016) suministrados por el Museo de Zoología de la Universidad de Costa Rica (UCR). Además, se obtuvo un árbol filogenético mediante topología concatenada multigénica de fragmentos de genes mitocondriales y nuclear. Los registros históricos revelan la presencia de 24 especies de cangrejos mitrácidos y su distribución geográfica en el Pacífico y Caribe de Costa Rica, incluyendo islas de la plataforma continental y oceánica. Los análisis moleculares confirman relaciones de parentesco entre los clados Ala-Maguimithrax, Omalacantha-Microphrys,Omalacantha+Microphyrs-Teleophrys y el clado bien soportado de las especies del género Mithraculus. Los resultados generados en este estudio contribuyen con información para el desarrollo de estrategias futuras de protección ambiental de los recursos marinos, al aportar una línea base para el monitoreo de la degradación ambiental y la destrucción del hábitat de cangrejos araña en las costas de Costa Rica. La información molecular obtenida a futuro permitirá estudios de genética de poblaciones, filogeografía, flujo génico regional y divergencia entre especies del Caribe y Pacífico.

Resumo O objetivo deste estudo foi determinar a distribuição, riqueza e identificação molecular de caranguejosaranha no litoral costarriquenho do Pacífico e do Caribe. Foram realizados mapas de distribuição de espécies da família Mithracidae nas costas do Caribe e do Pacífico da Costa Rica a partir de amostragens exploratórias e registros de espaço-tempo de coletas (1960 a 2016) fornecidos pelo Museu de Zoologia da Universidade da Costa Rica (UCR). Além disso, foi obtido um posicionamento taxonômico por meio da topologia multigênica concatenada de fragmentos genéticos mitocondriais e nucleares. Registros históricos revelam a presença de 24 espécies de caranguejos Mithracida e sua distribuição geográfica no Pacífico e Caribe da Costa Rica, incluindo ilhas da plataforma continental e oceânica. As análises moleculares confirmam relações de parentesco entre os clados Ala-Maguimithrax, Omalacantha-Microphrys, Omalacantha+MicrophyrsTeleophrys e o clado bem apoiado de espécies do gênero Mithraculus. Os resultados gerados neste estudo contribuem com informações para o desenvolvimento de futuras estratégias de proteção ambiental dos recursos marinhos, fornecendo uma linha de base para o monitoramento da degradação ambiental e a destruição do habitat do caranguejo-aranha no litoral da Costa Rica. As informações moleculares obtidas, no futuro, permitirão estudos de genética populacional, filogeografia, fluxo genético regional e divergência entre espécies do Caribe e do Pacífico.

Abstract The objective of this study was to determine the distribution, richness, and molecular identification of spider crabs in the Costa Rican Pacific and Caribbean coasts. Distribution maps were created for species of the Mithracidae family on the Caribbean and Pacific coasts of Costa Rica, based on exploratory samplings and spatio-temporal records of collections (1960 to 2016) provided by the Universidad de Costa Rica’s Museum of Zoology. In addition, phylogenetic relationships were explored using a multigene concatenated phylogenetic tree based on mitochondrial and nuclear gene fragments. Historical records reveal the presence of 24 species of mithracid crabs and their geographic distribution in the Pacific and Caribbean of Costa Rica, including islands on the continental and oceanic shelf. Molecular analyses confirm sister relationships between the clades Ala-Maguimithrax, Omalacantha-Microphrys, Omalacantha+MicrophyrsTeleophrys, and a well-supported clade of species belonging to the genus Mithraculus. However, our concatenated molecular data set suggests a monophyletic relationship between Thoe, Petramithrax, and Hemus, differing from what was previously reported. The results obtained in this study will help in the development of strategies for the environmental protection of these marine resources, by providing a baseline for monitoring environmental degradation and destruction of habitats used by spider crabs on the coasts of Costa Rica. Furthermore, the molecular information obtained in this study will help future studies focusing on understanding the population genetics, phylogeography, regional gene flow, and divergence among species between the Caribbean and Pacific coast.

Resumen La hoja Monterrey se ubica al noroeste de Costa Rica en el límite del arco volcánico activo y la cuenca de San Carlos (CSC), asociado con la sedimentación, el vulcanismo y la tectónica de la región tras-arco de América Central meridional. El objetivo y método de trabajo fue desarrollar el cartografiado geológico de los depósitos sedimentarios y volcánicos, la tectónica y el muestreo para dataciones radiométricas, geoquímica y petrografía de las diferentes unidades geológicas. Las rocas más antiguas de la Hoja Monterrey están constituidas por los sedimentos clásticos de la Formación Venado depositados en un ambiente de plataforma y transición continental de edad Mioceno Medio - Superior. La geocronología U-Pb del grupo de zircones detríticos más jóvenes en estos sedimentos, registran una edad de sedimentación máxima de 6,9 ± 0,2 Ma, sugiriendo una edad del Mioceno tardío y Plioceno de los sedimentos en esta región de la cuenca de San Carlos, correlacionable con dataciones previas de microforaminíferos, palinología y una edad radiométrica 40K/40Ar del vulcanismo que sobreyace estos sedimentos. La sedimentación del Plioceno en el área se interpreta como la colmatación de la cuenca asociado al cierre del istmo Centroamericano, registrado por una discordancia angular posiblemente asociado al evento tectónico registrado durante el final del Mioceno e inicios del Plioceno. El vulcanismo del Mioceno Superior es sub-alcalino de marcada afinidad toleítica y calco-alcalina y de transición a ambas series, variando de basaltos hasta dacitas. Los análisis geoquímicos sugieren una fuerte diferenciación de estos magmas a partir de fuentes de transición de tipo OIB (para las rocas de afinidad calco-alcalina/alcalina) a fuentes de tipo MORB (para los basaltos de afinidad toleítica) modificadas por los procesos de subducción. El vulcanismo piroclástico del Plio-Pleistoceno se asocia a ignimbritas de composición dacítica-andesítica calco-alcalina. En relación con magmas primarios, los análisis sugieren mayores o altos grados de la fusión parcial con un aporte de fluidos y sedimentos pelágicos carbonatados de la placa subducida al metasomatismo del manto. La normalización al manto primitivo indica enriquecimiento en LILE y deficiencias en HFSE asociado al aporte de fluidos y deshidratación de sedimentos marinos de la placa subducida al metasomatismo del manto, típico del vulcanismo de arco con una componente alcalina que puede estar más relacionada al vulcanismo del tras-arco que al vulcanismo del intra-arco del norte de Costa Rica. La Formación Monteverde de edad Pleistoceno inferior, abarca la mayor parte del área cerca del 78%, mayormente formando suelos de transición y residuales, constituido principalmente por andesitas, asociado también con un vulcanismo piroclástico y volcano-sedimentario presente en el sector suroeste de la hoja. La Formación Buena Vista conforma la actividad volcánica posterior a la Formación Monteverde y está constituido por depósitos volcaniclásticos (lahares) que forman brechas volcánicas muy endurecidas. Los depósitos piroclásticos Holocénicos del volcán Arenal (tefras) son de composición andesítica-andesítica basáltica calco-alcalina y se distribuyen al sur de la hoja. La tectónica compresiva del Mioceno Medio-Superior en el área está registrada por la deformación tectónica de fallas inversas en los sedimentos de la Formación Venado y la tectónica transtensiva del Plioceno y Pleistoceno por fallas principalmente de desplazamiento de rumbo consideradas activas. Las edades Cenozoicas y Mesozoicas obtenidas en zircones detríticos de la Formación Venado, registran el desarrollo y evolución del arco de islas de América Central meridional. En tanto, las edades Proterozoicas y Paleozoicas registran una posible conexión con el norte de América Central o sur de México, o un posible origen Gondwanico o Laurenciano. Sin embargo, podrían indicar también la presencia de fragmentos de corteza continental por debajo de América Central meridional. Estas edades de zircones primordiales son un aporte nuevo al conocimiento geocronológico y evolutivo de estos complejos continentales y proveen un paradigma para futuros estudios sobre la evolución geológica y geotectónica del istmo Centroamericano.

Abstract The Monterrey sheet is located in the northwest of Costa Rica in the limit of the active volcanic arc and the San Carlos basin (SCB), associated with the sedimentation, the volcanism and the tectonic of the back-arc region of southern Central America. The objective and methods were to develop the geological mapping of the sedimentary and volcanic deposits, the tectonic and the sampling for radiometric dating, geochemistry and petrography of the different units. The older rocks are conformed by clastic sediments belonging to Venado Formation, deposited in a shelf and transitional continental environment of Middle-Upper Miocene age. U-Pb geochronology for the youngest group of detrital zircons in these sediments constrained to a maximum depositional age of 6,9 ± 0,2 Ma, suggesting a late Miocene to Pliocene age sedimentation of the basin in this region of the SCB, which is in agreement with previous microforaminiferal and palynological dating and one 40K/40Ar radiometric age of the overlying volcanism on this sediments. The Pliocene sedimentation corresponds to the sealing of the basin associated with the Central American isthmus closure, recognized by an angular discordance associated with the tectonic event registered at the end of the Miocene and the beginning of the Pliocene. The Upper Miocene volcanism is subalkaline of marked tholeiitic and calc-alkaline afinity and transition to both series, varying from basalts to dacites. The geochemical analysis suggest a strong differentiation of these magmas from OIB type source (calc-alkaline/alkaline rocks) to MORB type source (tholeiitic basalts) modified by the subduction processes. The Plio-Pleistocene pyroclastic volcanism is associated to ignimbrites of calc-alkaline dacitic-andesitic composition. Related to primary magmas, the analysis suggest greater or high degrades of partial melting with an input of fluids and carbonate pelagic sediments from the subducting slab to the mantle metasomatism. The primitive mantle normalization shows LILE enrichments and HFSE depletions associated with the input of marine fluids and sediments dehydration of the subducted slab to the mantle metasomatism, typical of arc volcanism with an alkaline component that may be more related to the back-arc rather than the intra-arc volcanism of northern Costa Rica. The Monteverde Formation of the lower Pleistocene, cover most of the area of about 78%, forming transitional and sedentary soils mainly of andesite composition, associated also to a pyroclastic and volcaniclastic volcanism in the southwest of the sheet area. The Buena Vista Formation conform the subsequent volcanism of Monteverde Formation and is constituted by volcaniclastic deposits (lahars) of very indurate volcanic breccia. The pyroclastic Holocene deposits of Arenal volcano (tephra) are calc-alkaline of andesitic-basaltic andesite composition and are distributed to the south of the sheet. The compressive tectonic of the Middle to Upper Miocene is registered in the area by the tectonic deformation of thrusting faults in the sediments of the Venado Formation and the transtensive tectonic of the Plio-Pleistocene by mainly strike-slip faults considered active. The Cenozoic and Mesozoic detrital zircon ages of the Venado Formation, they register the development and evolution of the southern Central America volcanic arc, meanwhile, the Proterozoic and Paleozoic detrital zircon ages a possible connection with northern Central America or southern Mexico, or a possible Gondwanic or Laurentian origin. However, it could also indicate the presence of hidden continental crust fragments underneath southern Central America. These ancient detrital zircons ages constitute a new contribution to the geochronological knowledge and evolution of these continental complexes and provide a paradigm for future studies about the geologic and geotectonic evolution of the Central America isthmus.

Abstract The Azores archipelago has influenced Portuguese diplomacy for a long time. In 1871, Andrade de Corvo had already defended, in his book Perigos, that bringing Portugal closer to the United States should be one of the priorities of the Portuguese foreign policy, given the geostrategic position of the Azores. This outlook proved to be accurate in the last century, during the two world wars, with the installation of US military bases on these islands. Since then, the Azores have become indispensable for the Power projection of the American military power in the Atlantic, and has been the main reason for the invitation addressed to Portugal to join NATO. If the end of the Cold War, the appreciation of the Pacific and technological development posed serious challenges to the relevance of the Archipelago in the international system, it is necessary that the enlargement of the Portuguese Continental Platform, alone, given the geostrategic importance of the Islands, again it gives them prevalence within the context of Portuguese foreign policy.

Resumo O arquipélago dos Açores influi sobremaneira, desde há muito, na diplomacia portuguesa. Em 1871, já Andrade de Corvo defendera, no seu livro Perigos, que a aproximação de Portugal aos Estados Unidos deveria ser uma das prioridades da política externa portuguesa, dado o posicionamento geoestratégico dos Açores. Esta antevisão mostrou-se certeira no século passado, durante as duas guerras mundiais, com a instalação de bases militares norte-americanas nestas Ilhas. Desde então, os Açores tornaram-se imprescindíveis para a projecção do poder militar norte-americano no Atlântico e foram a principal razão para o convite endereçado a Portugal para aderir à NATO. Se o término da Guerra-Fria, a valorização do Pacífico e o desenvolvimento tecnológico colocaram sérios desafios à relevância do Arquipélago no sistema internacional, é mister que o alargamento da Plataforma Continental Portuguesa, só por si, dado o posicionamento geoestratégico das Ilhas, de novo lhes confira prevalência no âmbito da política externa portuguesa.

Resumo No Atlântico Tropical Sudeste, peixes da família Haemulidae desempenham um papel importante tanto ambientalmente, atuando como um elo entre os níveis tróficos mais baixos e mais altos, quanto socioeconomicamente, sendo amplamente capturados pelas frotas artesanais. Este estudo teve como objetivo descrever a ecologia trófica de três espécies de roncadores (Haemulon aurolineatum, H. plumierii e H. squamipinna) considerando aspectos espaciais, temporais e ontogenéticos integrando conteúdo estomacal e análise de isótopos estáveis. A amostragem ocorreu em 26 estações ao longo do Nordeste do Brasil (04°– 09°S), em agosto de 2015 e abril de 2017, utilizando rede de arrasto de fundo. Houve maior intensidade de alimentação à noite, em latitudes abaixo de 08°S e na plataforma continental interna. Valores mais altos de δ¹⁵N foram reportados para H. aurolineatum e H. plumierii coletados perto da linha costeira. A amplitude do nicho isotópico indicou que o H. aurolineatum tem uma dieta mais estreita do que o H. plumierii. Para as três espécies, o nível trófico variou entre três e quatro. Considerando o conteúdo estomacal e o nicho isotópico, a dieta foi semelhante comparando as espécies. Este padrão de ecologia trófica mostra um uso semelhante do habitat, que pode ser essencial para identificar áreas prioritárias para conservação em uma base ecossistêmica, especialmente em zonas ricas de recifes que estão sob várias pressões crescentes, como as do Nordeste do Brasil.

Abstract In the Southeastern Tropical Atlantic, Haemulidae family play an important role both environmentally, acting as a link between lower and higher trophic levels, and socioeconomically, being widely caught by artisanal fleets. This study aimed to describe the trophic ecology of three grunt species (Haemulon aurolineatum, H. plumierii and H. squamipinna) considering spatial, temporal and ontogenetic aspects, integrating stomach content and stable isotopes analysis. Sampling occurred in 26 stations along the Northeast of Brazil (04°– 09°S), in August 2015 and April 2017, using bottom trawling net. There was greater feeding intensity at night, at latitudes below 08°S and in the inner continental shelf. Higher values of δ¹⁵N were reported for H. aurolineatum and H. plumierii collected near coastline. The isotopic niche breadth indicated that H. aurolineatum has a narrower diet thanH. plumierii. For the three species, the trophic level ranged between three and four. Considering stomach content and isotopic niche, diet was similar comparing species. This trophic ecology pattern reveals a likewise use of the habitat, which may be essential for identifying priority areas for conservation on an ecosystem basis, especially in rich reef zones that are subject to several increasing pressures, such as those in Northeast Brazil.