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... Within this ecoregion, coastal species richness tends to concentrate both along the Antillean arc (Cuba to the southernmost Antilles) and the northern coast of South America (Venezuela-Colombia) [3]. Connected to the large biodiversity in the coasts of Venezuela and Colombia is the occurrence of a yearly coastal upwelling system, the Southern Caribbean Upwelling System (SCUS), which provides nutrients that power primary productivity [5]. The SCUS is probably the main source of the nutrients that support biological productivity in the oligotrophic Caribbean Sea and constitutes a priority coastal system for research and conservation of biodiversity in the TWA [2,5]. ...
... Connected to the large biodiversity in the coasts of Venezuela and Colombia is the occurrence of a yearly coastal upwelling system, the Southern Caribbean Upwelling System (SCUS), which provides nutrients that power primary productivity [5]. The SCUS is probably the main source of the nutrients that support biological productivity in the oligotrophic Caribbean Sea and constitutes a priority coastal system for research and conservation of biodiversity in the TWA [2,5]. This ecoregion, however, has high human coastal population densities, a long history of anthropogenic pressure upon its marine resources, and significant levels of land and water pollution [3,[6][7][8]. ...
... However, fifty more species of marine macroalgae have been reported for the eastern Guajira alone recently, and more species are expected to be found in this area if sampling power and range increase [21] (Figure 4). Macroalgae is the most diverse group of marine plants in Colombia [5]. Among Guajira's macroalgae groups, the red algae (Rhodophyta) are the most abundant and diverse [21,22]. ...
Article
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This paper describes the unique natural communities and biodiversity of the upwelling coastal system along the Guajira peninsula in the southern Caribbean Sea. The Guajira peninsula has a small human population with limited infrastructure and limited opportunities for coastal research, yet its coastal upwelling system is unique in the Tropical Western Atlantic region. This report includes both field observations along with a review of literature on the biodiversity of coastal eastern Guajira. In addition, it identifies missing information on the coastal system that is key to its management and conservation. Mangrove wetlands along with submerged aquatic vegetation (SAV) communities in a combination of consolidated and unconsolidated shorelines (e.g., rocky shores, cliffs, and beaches) form unique habitats in eastern Guajira. The diversity of these habitats is illustrated with the Bahia Hondita marine lagoon, where critical nursery habitat for several commercial valuable and endangered fisheries species, including sharks and sea turtles, is observed. Less information is available on more cryptic fauna, invertebrates, and coastal plankton species. Several anthropogenic factors are threatening species diversity in coastal Guajira, including overgrazing, mining, and target-species overfishing. Additional threats, such as extreme weather events (e.g., storms and droughts) as well as changes in coastal water quality, are also impacting species. The protection of the Guajira’s biodiversity would depend on local communities’ governance and empowerment as well as law enforcement for mining and agriculture operations. Management plans can include reducing land-based sources of pollution and building coastal resilience for climate change.
... La surgencia de la Guajira es regulada estacionalmente, mostrando una alta salinidad superficial (Dessier & Donguy, 1994). El transporte de Ekman fuera de la costa es de alrededor 5x10 3 kgm −1 s −1 (Rueda & Muller-Karger, 2013). Se estima una surgencia de 6x10 −4 cms −1 en el fondo de la capa de Ekman con intensidades máximas de 180 km de la costa de la Guajira (Gordon, 1967), pero un flujo vertical de 4,4x10 −3 cms −1 fue calculado por (Fajardo, 1979;Rueda & Muller-Karger, 2013). ...
... El transporte de Ekman fuera de la costa es de alrededor 5x10 3 kgm −1 s −1 (Rueda & Muller-Karger, 2013). Se estima una surgencia de 6x10 −4 cms −1 en el fondo de la capa de Ekman con intensidades máximas de 180 km de la costa de la Guajira (Gordon, 1967), pero un flujo vertical de 4,4x10 −3 cms −1 fue calculado por (Fajardo, 1979;Rueda & Muller-Karger, 2013). Esta surgencia estimula el crecimiento de fitoplancton, pero el agua es relativamente empobrecida en nutrientes respecto a otros afloramientos (Corredor, 1979;Rueda & Muller-Karger, 2013). ...
... Se estima una surgencia de 6x10 −4 cms −1 en el fondo de la capa de Ekman con intensidades máximas de 180 km de la costa de la Guajira (Gordon, 1967), pero un flujo vertical de 4,4x10 −3 cms −1 fue calculado por (Fajardo, 1979;Rueda & Muller-Karger, 2013). Esta surgencia estimula el crecimiento de fitoplancton, pero el agua es relativamente empobrecida en nutrientes respecto a otros afloramientos (Corredor, 1979;Rueda & Muller-Karger, 2013). ...
Research Proposal
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Analyze the behavior of atmospheric variables (atmospheric pressure, surface ambient temperature, wind) and oceanic variables (sea level, salinity and sea surface temperature) in the Caribbean Sea by 2100, using results of AOGCM's CMIP5 models, before different emission scenarios (CPRs).
... The upwelling of the Guajira is seasonally regulated, showing high surface salinity (Dessier & Donguy, 1994). Ekman's off-shore transport is about 5x10 3 kgm −1 s −1 (Rueda & Muller-Karger, 2013). An upwelling of 6x10 −4 cms −1 is estimated at the bottom of the Ekman layer with maximum intensities of 180 km from the coast of La Guajira (Gordon, 1967), but a vertical flow of 4.4x10 −3 cms −1 was calculated by (Fajardo, 1979;Rueda & Muller-Karger, 2013). ...
... Ekman's off-shore transport is about 5x10 3 kgm −1 s −1 (Rueda & Muller-Karger, 2013). An upwelling of 6x10 −4 cms −1 is estimated at the bottom of the Ekman layer with maximum intensities of 180 km from the coast of La Guajira (Gordon, 1967), but a vertical flow of 4.4x10 −3 cms −1 was calculated by (Fajardo, 1979;Rueda & Muller-Karger, 2013). This upwelling stimulates the growth of phytoplankton, although the water is relatively poor in nutrients compared to other outcrops (Corredor, 1979;Rueda & Muller-Karger, 2013). ...
... An upwelling of 6x10 −4 cms −1 is estimated at the bottom of the Ekman layer with maximum intensities of 180 km from the coast of La Guajira (Gordon, 1967), but a vertical flow of 4.4x10 −3 cms −1 was calculated by (Fajardo, 1979;Rueda & Muller-Karger, 2013). This upwelling stimulates the growth of phytoplankton, although the water is relatively poor in nutrients compared to other outcrops (Corredor, 1979;Rueda & Muller-Karger, 2013). ...
Thesis
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This study identifies possible changes in the Caribbean Sea during the 21st century using three climate models provided by the Coupled Model Intercomparison Project Phase 5 (CMIP5) under the Historical scenario and using two representative emission scenarios (RCP4.5, RCP8.5). The assessment includes ambient air surface temperature, atmospheric pressure and wind, as well as surface ocean temperature, surface salinity and mean sea level changes in 2050 and 2100 referenced to 2005. Results indicate that regardless of the RCP used, there will be considerable increases in air (1.5 to 4.0 °C) and sea surface temperature (1.4 to 2.9 °C), what has the potential to broaden the hurricane season and increase their frequency of occurrence in the region. Besides, ocean temperature rise will probably enhance the coral bleaching in the Caribbean Sea. Mean sea level trends show a notable increase in the period 2005-2100 (24.02 to 70.94 cm/century) compared to the periods 1960-2005 (4.53 to 14.64 cm/century) and 1850-2005 (2.44 to 9.42 cm/century). Although expected sea level trends in the Caribbean are below the median of global projections, due to the regional microtidal environment, such trends have the potential to enhance flooding and erosion, putting in risk low level islands such as some in the San Andres and Providencia Archipelago.
... La surgencia de la Guajira es regulada estacionalmente, mostrando una alta salinidad superficial (Dessier & Donguy, 1994). El transporte de Ekman fuera de la costa es de alrededor 5x10 3 kgm −1 s −1 (Rueda & Muller-Karger, 2013). Se estima una surgencia de 6x10 −4 cms −1 en el fondo de la capa de Ekman con intensidades máximas de 180 km de la costa de la Guajira (Gordon, 1967), pero un flujo vertical de 4,4x10 −3 cms −1 fue calculado por (Fajardo, 1979;Rueda & Muller-Karger, 2013). ...
... El transporte de Ekman fuera de la costa es de alrededor 5x10 3 kgm −1 s −1 (Rueda & Muller-Karger, 2013). Se estima una surgencia de 6x10 −4 cms −1 en el fondo de la capa de Ekman con intensidades máximas de 180 km de la costa de la Guajira (Gordon, 1967), pero un flujo vertical de 4,4x10 −3 cms −1 fue calculado por (Fajardo, 1979;Rueda & Muller-Karger, 2013). Esta surgencia estimula el crecimiento de fitoplancton, aunque el agua es relativamente empobrecida en nutrientes respecto a otros afloramientos (Corredor, 1979;Rueda & Muller-Karger, 2013). ...
... Se estima una surgencia de 6x10 −4 cms −1 en el fondo de la capa de Ekman con intensidades máximas de 180 km de la costa de la Guajira (Gordon, 1967), pero un flujo vertical de 4,4x10 −3 cms −1 fue calculado por (Fajardo, 1979;Rueda & Muller-Karger, 2013). Esta surgencia estimula el crecimiento de fitoplancton, aunque el agua es relativamente empobrecida en nutrientes respecto a otros afloramientos (Corredor, 1979;Rueda & Muller-Karger, 2013). ...
Thesis
Full-text available
Este estudio identifica posibles cambios en el Mar Caribe durante el siglo XXI utilizando tres modelos climáticos proporcionados por la Quinta Fase del Proyecto de Intercomparación de Modelos Acoplados (CMIP5) bajo el escenario HISTORICAL y utilizando dos escenarios de emisiones representativos (RCP4.5, RCP8.5). La evaluación incluye la temperatura de la superficial del aire, la presión atmosférica y el viento, así como la temperatura superficial del océano, salinidad superficial y los cambios del nivel medio del mar en 2050 y 2100 con respecto a 2005. Los resultados indican que independientemente del RCP utilizado, habrá aumentos considerables en temperatura del aire (1.5 a 4.0 °C) y de la superficie del mar (1.4 a 2.9 °C), lo que tiene el potencial de ampliar la temporada de huracanes y aumentar su frecuencia de ocurrencia en la región. Además, el aumento de la temperatura del océano probablemente incrementara el blanqueamiento de los corales en el Mar Caribe. Las tendencias medias del nivel del mar muestran un aumento notable en el período 2005-2100 (24.02 a 70.94 cm/siglo) en comparación con los períodos 1960-2005 (4.53 a 14.64 cm/siglo) y 1850-2005 (2.44 a 9.42 cm/siglo). Si bien las tendencias esperadas del nivel del mar en el Caribe están por debajo de la mediana de las proyecciones globales, debido al ambiente micromareal de la región, tales tendencias tienen el potencial de aumentar las inundaciones y la erosión, poniendo en riesgo islas de bajo nivel como algunas del Archipiélago de San Andrés y Providencia.
... Hourly METAR data from 1997-2015 of the Rafael Núñez International Airport (approximately 10 km north of the bay) show that from January to April the winds are strongest and predominantly northerly. This period of strong trade winds coincides with the strengthening of the southern Caribbean upwelling system which contributes to cooler water temperatures (Andrade & Barton, 2005;Rueda-Roa & Muller-Karger, 2013). From August to November, breezy conditions are observed when weaker winds come from a large range of directions, with a prominent westerly component in September and October. ...
... The influence of the windy season on the bay's water quality is evident in higher salinity values as the winds increase the seawater's vertical mixing. Temperature was cooler at the surface and bottom of all stations during this season due to increased circulation and the influence of the southern Caribbean upwelling system (Andrade & Barton, 2005;Rueda-Roa & Muller-Karger, 2013). Wind-driven circulation would also explain the seasonal improvement in oxygen levels, along with the associated lower water temperature, and may contribute to the resuspension of bottom sediments resulting in higher turbidity found in bottom waters during this period. ...
... The Dique Canal's highest discharges typically occur from October to December, while its lowest levels occur from February to April. Winds are strongest and predominantly northerly from January to April due to the trade winds which coincide with the strengthening of the southern Caribbean upwelling system and the cooling of water temperatures (Andrade & Barton, 2005;Lonin et al., 2010;Rueda-Roa & Muller-Karger, 2013). Breezy conditions are observed from August to November, when weaker winds come from highly variable directions. ...
Thesis
Full-text available
This thesis presents research on coastal water processes and the development of tools for marine and coastal management. The research is applied to Cartagena Bay, Colombia, one of the Caribbean’s hot-spots of coastal pollution, known to be impacted by land-based sources of pollution, including continental runoff, industrial effluents and domestic wastewater. Management of coastal water bodies such as Cartagena Bay requires tools to assess pollution impacts, land-based discharges and potential mitigation plans, while effective policy is needed to establish coastal water quality standards. Through four individual yet related manuscripts, the research presented in this thesis combines water and sediment quality monitoring with hydrodynamic and water quality modelling in order to conduct a diagnostic of pollution impacts, evaluate the effect of mitigation plans on coastal circulation, and develop novel methods for assessing land-based pollution sources and setting coastal water quality targets. An exhaustive monthly monitoring program of 14 water quality parameters and an analysis of seven metals in sediments demonstrated the spatio-temporal extent and seasonal variability of water and sediment pollution in Cartagena Bay. Potential pollution impacts were evident as nearly all of the measured parameters were found at inadequate levels in comparison to recommended threshold values for marine conservation and recreational adequacy. These included total suspended solids, turbidity, biological oxygen demand, nitrate, phosphate, total phosphorus, phenol, faecal coliforms and enterococci, which were all highest in waters during the rainy season. The transitional season yielded higher temperatures and lower dissolved oxygen concentrations. Increased chlorophyll-a concentrations in the water column during dry season, when water transparency improves, suggest that primary productivity in this eutrophic system is limited by light rather than nutrients. Concentrations of mercury, cadmium, chromium, copper and nickel found in the bay’s sediments were indicative of potential impacts on marine life. These findings are important to coastal management, as they justify mitigation actions and support policy development. The task of identification and prioritization of pollution sources is essential but complicated when there are a variety of pollution sources and data is limited. This study presents a methodology for the integrated assessment of anthropogenic pollution sources in the coastal zone by estimating pollutant loads and comparing their relative contributions to receiving coastal waters. This approach combines various methods of load estimation based on monitoring, GIS analyses and previous research, while emphasizing the importance of calculating confidence intervals for each load value. Results showed that continental runoff from the Dique Canal is the principal source of sediments and phosphorus, nearby domestic wastewater is the principal source of coliforms, while significant loads of nitrogen and organic matter are contributed by continental runoff, domestic wastewater as well as nearby industrial wastewater. Mitigation of pollution sources to date has focussed on freshwater flow from the Dique Canal. This flow has been projected to increase in future years, but there are plans to reduce it by constructing upstream hydraulic doors. Given the influence of freshwater discharge on coastal water renewal processes, a calibrated 3D hydrodynamic model (MOHID) and a coupled Lagrangian transport model were applied to assess how these upstream changes will affect the bay’s hydrodynamic processes. Mean residence times of 3-6 days and flushing times of 10-20 days were estimated for water from the Dique Canal in the bay, while mean residence times of 23-33 days and flushing times of 70-99 days were calculated for the bay’s complete water volume. The variability of these water renewal times depends primarily on the canal’s discharge level and secondarily on prevailing winds. An assessment of future scenarios showed that increases in freshwater runoff would result in faster water renewal in the bay, while plans to decrease freshwater discharge by constructing hydraulic doors would result in slower water renewal. It is therefore imperative that any plans for reducing fluvial fluxes into the bay be accompanied by the control of local pollution sources, which are abundant and could worsen the bay’s water quality should water renewal times become longer. Effective management of pollution sources requires policy on coastal water quality that considers ecologically-relevant thresholds and has a scientific foundation linking land-based discharges with marine water quality. This study demonstrates a practical method for setting local-scale coastal water quality targets for end-of-river suspended sediment loads in order to mitigate offshore coral reef turbidity impacts. The approach considers reef thresholds for suspended solid concentration and uses monitoring data to calibrate and apply a coupled 3D hydrodynamic-water quality model (MOHID) to link the marine thresholds to fluvial loads. Results showed that ecosystem suspended solids thresholds could be maintained within the extent of Cartagena Bay by reducing current suspended sediment loads in the Dique Canal by approximately 80-90% to target loads of 500-700 t/d. The substantial reductions that are needed reflect ongoing issues in the Magdalena watershed which has experienced severe erosional conditions and intense deforestation over the past four decades. Though these studies are demonstrated in Cartagena Bay, the presented methods would be practical for application in other developing countries that similarly lack long-term datasets. The Wider Caribbean Region is strongly dependent on its natural coastal resources though pollution issues common throughout the region place these resources at risk. This thesis’ approach to assessing pollution impacts, land-based sources, potential mitigation plans and developing targets for coastal water quality standards thus makes a valuable contribution to the development of coastal management tools that are applicable to similar polluted waters in the region.
... The sectors in Figure 3a were defined by Rodriguez et al. (2010) from a spatial and temporal analysis of multiyear surface atmospheric (Ta and relative humidity, RH) and oceanic (sea surface temperature, SST and sea surface salinity, SSS) data for the CCS. The sectors in Figure 3b are the result of cluster analysis of multiyear SST, SSS, and sea surface density anomaly (SSDA) data carried out by Villegas & Malikov (2009) for the CPB. Figure 3a shows on the left the Caribbean Warm Pool (CWP), the Caribbean Cold Pool (CCP), and the La Guajira Upwelling system (LGU), sectors which are mentioned and studied in Ruiz-Ochoa et al. (2012), Rueda-Roa & Muller-Karger (2013), Andrade (2015), and others. The homogeneous zones for CPB, which are shown in Figure 3b on the right, are known as Cold Coastal Surface Water (CCSW), Warm Coastal Surface Water (WCSW), Surface Mixing Water (SMW), Colombian Surface Water (CSW), Tropical Surface Water (TSW), and Equatorial Surface Water (ESW). ...
... Atmospheric forcing introduced into ROMS allows to simulation in CCS the general characteristics identified by Ruiz-Ochoa et al. (2012) and Pareja et al. (2013) as CWP and CCP (Fig. 3a) but soften the influence of local meteorological and continental factors that have been described by Restrepo & Kjerfve (2004), Poveda et al. (2006) and Whyte et al. (2008), among others. These factors are the CLLJ and the northeast trade winds, which generate the LGU, where cold waters were located (Rueda-Roa & Muller-Karger 2013). Low SST amplitude values obtained in the ROMS series (Table 1), especially for PG and PB, show that the model failed to reconstruct significant SST variations in these stations. ...
... Differences in SST trends between PG, PB, and TP are appreciated (Fig. 8, Table 3). Although these stations are close to each other in CCS, the eastern zone is influenced by stronger winds causing a high turbulence level (Rueda-Roa & Muller-Karger 2013), which implies differences in SST and differentiation in responses to climate change. Therefore, for each simulated sector, it is necessary to consider local factors that govern the atmospheric and oceanic circulation. ...
Article
Full-text available
Sea surface temperature (SST) simulation for the 1970-2007 period and its projection up to 2035 was carried out with the Regional Ocean Modeling System (ROMS) for the Colombian Caribbean Sea (CCS) and the Colombian Pacific Basin (CPB). Spatial bias using the International Comprehensive Ocean-Atmosphere Data Sets (ICOADS) and Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA) for 1982-2007 shows an adequate representation of surface characteristics in both marine study regions, especially on the CPB. The 1970-2007 period's deviation measures reveal a good fit between ICOADS data and simulated SST. The spatial distribution of linear multi-annual regression (ICOADS 1970-2007) evidences a similar positive trend in both regions (0.01ºC yr-1). Differences in the spatial distribution of trends between the two regions (ROMS 2008-2035) prescribe that general warming of CCS will be less (0.01ºC yr-1) than that of CPB (0.02ºC yr-1). The average SST trend in waters close to continental and insular coastal stations of CCS and CPB obtained from ICOADS (1970-2015) are 0.016 and 0.013°C yr-1, respectively. The average trend in the same stations obtained from the projection using ROMS (2008-2035) is 0.025°C yr-1 for CCS and 0.015°C yr-1 for CPB. The SST projection for 2008-2035 in the CCS shows the highest SST increase slope in waters near Punta Gallinas and in the CPB it is evidenced in waters near Malpelo Island.
... W), located north of Santa Marta, Colombian Caribbean (See Figure 4). It is characterized by the exposure of the northeast trade winds and high biological productivity due to the nutrient load products of this phenomenon [1,2]. This area is influenced by two main climatic periods, the major dry season (December-April) and a minor dry season (July-August), which is also known as " Veranillo de San Juan" [3]. ...
... The atmospheric data were obtained with a spatial resolution of 25 km, from the daily average of surface zonal winds (U) and surface meridional winds (V), with the ASCAT sensor L2b 12.5 (The Advanced Scatterometer) on board the EUMETSAT satellite [1,5]. These data were reprocessed at a spatial resolution of 1 km. ...
Article
Full-text available
This paper presents a dataset on the abiotic (oceanographic, atmospheric and global climatic indices) and fishery variables of the marine-coastal area of the Magdalena Province in the area between Taganga and Bahía Concha, located north of Santa Marta in the Colombian Caribbean. The abiotic variables were downloaded from the satellites of the National Aeronautics and Space Administration (NASA) and the meteorological stations of the Institute of Hydrology, Meteorology and Environmental Studies (IDEAM). The fishery variables were obtained through field trips in the study area. A dynamic artificial neural network was implemented to reconstruct the missing data in the fishery variables from the known abiotic variables (Precipitation, North Atlantic Oscillation and Multivariate ENSO Indices). In this way, a dataset was obtained that is important to determine the historical changes of fishery resources for the study area and to make catch forecasts incorporating the variability of the environmental conditions (atmospheric and oceanographic).
... The Santa Marta Coastal Area (SMCA), located in the Colombian Caribbean Sea, is highly influenced by seasonal upwelling (Andrade and Barton, 2005;Rueda-Roa and Muller-Karger, 2013) and it is affected by several anthropogenic pressures (e.g. a sewage outfall, harbor activities, rivers discharge). Seasonal coastal upwelling causes a high temporal variability in water temperature, nutrient and Chl-a concentrations and water circulation patterns (Arévalo-Martínez and Franco -Herrera, 2008; Ramírez-Barón et al., 2010). ...
... The regional climate and oceanographic dynamics of SMCA are strongly determined by the strength of the Caribbean Lowlevel Jet of the Northeast (NE) Trade Winds and North (N) -South (S) oscillations of the Intertropical Convergence Zone (ITCZ) (Andrade and Barton, 2005). NE winds parallel to the coastline trigger northward Ekman transport and the subsequent upwelling of subsurface waters from the Southern Caribbean upwelling system (SCUS) (Andrade and Barton, 2005;Arévalo-Martínez and Franco -Herrera, 2008;Paramo et al., 2011;Rueda-Roa and Muller-Karger, 2013). The coastal upwelling is strongly influenced by the intensity of the NE trade winds. ...
Article
A coupled 3D hydrodynamic-ecological model was applied to the Santa Marta Coastal Area (SMCA, Colombian Caribbean) to provide insights into the role of external stressors (e.g. wastewater outfall and upwelling) on the water quality and benthic – pelagic coupling. The model was calibrated and validated based on benthic metabolic measurements, satellite–derived chlorophyll-a (Chl-a) and sea surface temperature (SST) maps, field and literature water quality data. The model was able to reproduce the complex dynamics and fast transitions of temperature, nutrients, and phytoplankton, including the stratification and mixing periods during the non-upwelling (NUPW) and upwelling (UPW) seasons. Wide and fast changes in the temperatures and the highly flushed environment prevented excess phytoplankton growth and nutrient accumulation in the benthic and pelagic compartments. The model proved to be a reliable research tool to analyze the interactive effects of upwelling and untreated wastewater on the functioning of a tropical bay.
... Ma, while modern upwelling systems in the Caribbean are restricted to its southwest margin along the coasts of Colombia, Trinidad, and Venezuela (O'Dea et al., 2007;Lessios, 2008). Modern upwelling in the southern Caribbean is spread in 21 localized upwelling areas driven by seasonally strengthened westward trade winds that flow semi-parallel to the coastline, generating northward Ekman transport of warm surface waters and permitting upwelling of nutrient-rich underwaters (Muller-Karger et al., 1994;Andrade and Barton, 2005;Rueda-Roa and Muller-Karger, 2013;Correa-Ramirez et al., 2020). Upwelling intensity is controlled by the trade winds in the Caribbean low-level jet, the coast line orientation, the presence of nearby deltas and the zonal differences on the water column stratification (Correa-Ramirez et al., 2020), and can reach in some sites chlorophyll-a values of 1.65 mg m-3 (Rueda-Roa and Muller-Karger, 2013) similar in magnitude to the upwelling in the Panama bay on the Pacific side of Panama (1.5 mg m-3 D' Croz and O'Dea, 2007). ...
Article
The upper Miocene Chagres Formation, cropping out along the Caribbean coast of Panama, has been previously interpreted as the record of the last deep-water connection between the Caribbean and Pacific oceans based on bodyfossil paleodepth estimates. We test this interpretation by presenting an integrated ichnological and sedimentological analysis on eight coastal localities of the Chagres Formation (Toro Limestone and Chagres Sandstone members). The Toro Limestone Member accumulated under fully marine conditions in a mixed carbonate and siliciclastic marine shelf above storm wave base. Fluctuating high-moderate energy conditions modulated by a combination of tides and high energy currents likely led to the sparse bioturbation of Toro Limestone sediments, corresponding to an archetypal Cruziana ichnofacies assemblage. Bioturbation, dominated by Thalassinoides and Ophiomorpha isp., increases in the overlying Chagres Sandstone Member and corresponds to a proximal expression of the Cruziana ichnofacies. The Chagres Sandstone Member was deposited within the lower shoreface-upper offshore transition zone in a shelf with low sedimentation rates under combined storm, wave, and tidal influence, and includes fossils and sediments of continental origin suggesting proximity to a river mouth. Our results suggest that the Chagres Formation accumulated in shallow waters, contrasting with a previously proposed deep-water accumulation, and are consistent with deposition on a tectonically stable platform of the northern Canal Basin at the apex of the Panama orocline.
... Longitud de onda (nm) (3,90 µg·L ). Estos resultados generalmente ocurren como consecuencia del incremento en el afloramiento costero, que en las costas nororientales se observan normalmente en los meses de febrero, marzo y abril (Muller-Karger et al., 1989;Aparicio, 1994;Rueda-Roa & Muller-Karger, 2013;Jury, 2018). ...
Article
span lang="ES">Se evaluaron los niveles de metales pesados en ejemplares machos y hembras del bivalvo Atrina seminuda (Lamarck, 1819). Los organismos fueron colectados en la localidad de Guayacán, estado Sucre, Venezuela. Las concentraciones Cu, Cd, Cr, Ni, Pb, Fe y Zn se determinaron en los tejidos: gónada (G), músculo (M), hepatopáncreas (H) y resto (R) mediante espectroscopia de emisión de plasma de acoplamiento inductivo (ICP-OES). El índice gonadosomático (IGS) presentó diferencias significativas, mostrando su valor más alto en febrero (19,67 ± 0,43) y el menor en junio (13,26 ± 0,43). Las concentraciones de metales presentaron diferencias significativas entre los tejidos analizados; observándose en general una mayor acumulación de metales en el H y el R. Se mostraron variaciones mensuales significativas de los metales en los tejidos con las mayores concentraciones de Cu, Cd, Cr, Ni y Zn entre los meses de abril y mayo. El análisis de ACP determina que IGS está asociado a la incorporación de los metales Estas variaciones mensuales en los metales analizados, puede ser explicado por la biodisponibilidad de estos elementos determinada en parte por los elevados niveles de clorofila a, que es característico el afloramiento en el área nororiental del país y por la variación del ciclo reproductivo de la especie estudiada.</span
... Moreover, variation in physical parameters, including temperature (Mora, 2015), surface currents (McEachran, 2009) and local upwelling systems (Jury, 2011;Rueda-Roa et al., 2018;Rueda-Roa & Muller-Karger, 2013), have been found to be associated with differences in fish composition. For example, the lower sea temperatures and reef cover in the temperate northern Gulf of Mexico compared with conditions in the southern Gulf and tropical Caribbean Sea align with a difference in species richness and composition (Fautin et al., 2010;Ward, 2017). ...
Article
Aim Tropical America, including the Tropical Eastern Pacific and the Caribbean Sea, presents a high level of marine biodiversity, but its fish fauna has been poorly documented. In early studies marine species distributions were interpreted based on tectonic activity during the late Cenozoic, while more recent studies have highlighted a link with the present‐day environment. Here, we described the assemblage richness and composition of fishes in Tropical America and related these properties to both the past evolution of marine environmental conditions and current environmental gradients. Location Tropical America. Taxon Demersal and benthic fishes. Methods We mapped the distribution of 2,216 demersal and benthic fish species of Tropical America using existing occurrence data. We computed three assemblage indicators: species richness, composition and nestedness, which we explained by environmental gradients. We linked compositional distance to environmental differences using distance‐based redundancy analysis, species richness and nestedness using a generalized linear model. We ran simulations of a mechanistic model in which three processes determine the spatial dynamics of biodiversity: speciation, dispersal and extinction. This model yielded estimates for species assemblage properties following palaeogeographic changes in the region that shaped the current coastal habitat configuration. Results Fish species richness in Tropical America peaks around the Florida Peninsula, Bahamas and Greater Antilles. Fish composition varies along a depth gradient, between the Tropical Eastern Pacific and the Caribbean Sea, and forms distinct domains within the Caribbean region. The nestedness component of β‐diversity is lower in shallower assemblages, especially those along the outer section of the Greater Caribbean. Species richness and nestedness are partly explained by current environmental conditions, but model simulations illustrate how this may be further explained by the tectonic history of the region. Main conclusions Species richness peaks in the Greater Caribbean, coinciding with generally favourable current environmental conditions for demersal and benthic fishes. The high species richness and the low nestedness of fish assemblages in the Cuba region are compatible with the results of palaeo‐environmental changes that have occurred in that area. Effects of the plate tectonic history might still be present in the organization of fish fauna in this region.
... The lack of upwelling is corroborated by temperature measurements which ranged from 26.5 to 30.5°C on the north and 26.7 to 30.7°C on the south. These are above 22°C which would indicate upwelling from the "Subtropical Underwater core" and are within the range expected of the central Caribbean without upwelling (Rueda-Roa & Muller-Karger, 2013). ...
Article
Many Caribbean reefs have shifted from coral dominance to macroalgal dominance, often by brown algae such as Dictyota and Lobophora. However, the north side of Cayman Brac in the Cayman Islands is dominated seasonally by the green macroalga Microdictyon (percent cover of Microdictyon is 4% in the winter and ~40% of the reef in the summer), although it is absent from the south side of the island and the remainder of the country. Indeed, Microdictyon is rare in much of the Caribbean, so this situation on Cayman Brac provides an opportunity to investigate the conditions that facilitate its distribution and dominance. The impact of herbivory, competition, nutrient input and other abiotic conditions were examined as factors that could influence the distribution and dominance of Microdictyon. While herbivory or nutrient input are frequently found to be key drivers of benthic community composition on coral reefs, here consumption of Microdictyon by herbivores was low, and thus, the alga was not subject to strong top‐down control by herbivory. So, in this case, neither herbivore abundance nor feeding preference appeared to influence the distribution of Microdictyon. Nutrient input was also similar to both sides of the island suggesting nutrients played little role in differential distribution. But, in a controlled transplant experiment where Microdictyon was protected from herbivory and competition, it experienced almost complete mortality (93.3%) when transplanted to the south side, compared to only 11.8% mortality on the north. The south side was exposed to the strongest wave action 92% of the days in our study and was on average a slight, but significant 0.2°C warmer. Thus, these data suggest physical forcing (i.e. wave exposure) is the most likely factor dictating Microdictyon distribution. Conversely, a combination of reduced herbivory and increased competitive strength may explain the seasonal dominance of Microdictyon on the north side of Cayman Brac. Microdictyon was a competitive inferior to the other common algae in winter but increased in competitive strength to equal other species in summer. These results add to the literature on Microdictyon and on the forces impacting benthic community structure of coral reefs.
... However, the apparent main season for parturition and mating registered during November-February appears to be related with the seasonal upwelling system that influences the north-eastern coast of Venezuela. This oceanographic event has a major influence during the first months of the year (January-April) when strong winds drive the mixing of water masses and nutrients (Castellanos et al., 2002;Rueda-Roa & Muller-Karger, 2013); and then contributes to the high marine productivity by increasing primary production and abundance of marine fauna in the region (Freon & Mendoza, 2003). In the study area, water temperature varies between 20.5 and 29.7°C during the principal and relaxation upwelling periods, respectively (Castellanos et al., 2002;McConnell et al., 2009). ...
Article
The reproductive biology and embryonic development of Mustelus higmani were examined between January 2015 and December 2016 in the southeastern Caribbean. Captures comprised 813 females (23.2-72.5 cm TL), and 960 males (22.6-62.5 cm TL). The total length at 50% maturity was estimated as 47.8 and 47.5 cm for females and males, respectively. Uterine fecundity ranged from 1 to 8 embryos and ovarian fecundity between 1 and 9 vitellogenic follicles. The time of parturition and mating season of M. higmani may occur throughout the year, peaking between November and February. The presence of pre-ovulatory ovarian follicles along with advanced embryos indicates an annual reproductive cycle for female M. higmani. The main embryonic development stages were recorded in the samples, from uterine eggs (1 to 6 per female) to term embryos (23.0-26.0 cm TL). The transition between placental preimplantation and postimplantation occurs when embryos have attained a TL of 5.0-6.0 cm. The observation of abundant uterine histotrophic secretions in late pregnant and post-partum females demonstrates that histotrophy may intensify close to birth in this species. The local population of M. higmani appears to have relatively high productivity; nonetheless, this species is heavily harvested and lacks management measures in the study area.
... crabs, shrimps, and other benthic invertebrates) (Wildermann et al., 2009;Wildermann and Barrios-Garrido, 2012). Encounters of loggerheads at the Kazuzain landing sites may be indicative of fishers venturing southwards within the Gulf of Venezuela in search of more productive fishing areas (Rueda-Roa and Muller-Karger, 2013;Rojas-Cañizales, 2015;. Further understanding of loggerhead movements in the Gulf of Venezuela is crucial, as this area is potentially used by large immature individuals for a limited developmental period prior to migrating to reproductive habitats (Barrios-Garrido et al., 2020a). ...
Article
The impact of artisanal fisheries on marine turtle populations is still understudied in the southern Caribbean. In the Venezuelan Guajira Peninsula, artisanal fishing of marine turtles by the indigenous Wayuú people has occurred for generations. Nevertheless, understanding the issues regarding turtle take is challenging. Surveys and semi-structured interviews were carried out at eight landing sites located in three different zones in Kazuzain village, Middle Guajira. Carapaces or plastrons were recorded to estimate take level, and measured to determine life stage. Minimum take was 167 marine turtles over 53 weeks, or 3.15 turtles/week on average (estimated 163.8/yr). Most records encountered were from green turtles (n=154; 92.2%), and the majority of these were immature (n=76; 89.4%). Key- informants reported that marine turtles were not the target catch. However, most interviewees affirmed that take of marine turtles in Kazuzain is not only for traditional purposes, but also to meet economic shortfalls. They also stated that trade of marine turtles has increased over the last ten years due to the Venezuelan economic crisis. This is the first assessment of marine turtle take in this village and fills an information gap that can aid resource managers to mitigate the impacts of take, and develop potential conservation solutions for marine turtle aggregations and the people that depend on them.
... W) to Barranquilla, Colombia (75.51° W;Rueda-Roa & Muller-Karger 2013). A significant biogeographic break in this region has been identified for other groups including catfishes of the genus Cathrops (Betancur et al. 2010) Etymology. ...
Article
Acanthemblemaria aceroi new species is described from the upwelling region of the Caribbean coasts of Venezuela and Colombia. It differs from its closest relative, Acanthemblemaria rivasi Stephens, 1970, known from Panama and Costa Rica, in the posterior extent of the infraorbitals, details of head spination, and unique COI sequences. The description of Acanthemblemaria johnsonsi Almany & Baldwin, 1996, heretofore known only from Tobago, is expanded based on specimens from islands offshore of eastern Venezuela.
... Both La Guajira and Santa Marta are foci of the seasonal Southern Caribbean Upwelling System (Arévalo-Martínez and Franco-Herrera, 2008; Rueda-Roa and Muller-Karger, 2013). This coastal upwelling system is the result of the Caribbean Low-Level Jet of the north trade winds, which blows almost parallel to the coast of Colombia during the first third of the year (January to May), a period known as the "dry season" (Invemar and Corpoguajira, 2012). ...
Article
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The Atlantic green sea turtle Chelonia mydas is a migratory and endangered species with a network of nesting rookeries (NRs) and foraging grounds (FGs) in the Atlantic basin that needs elucidation. FGs are important areas for immature turtle’s feeding and growth after pelagic migrations. Aggregations of sea turtles at these grounds usually come from genetically distinct NRs; therefore, they are called mixed stocks. The northeastern coast of Colombia has extensive seagrass and macroalgae marine ecosystems that constitute FGs, and perhaps long-term developmental habitats for a significant number of immature C. mydas. However, it is unknown which C. mydas NRs may be using these ecosystems for feeding and development. This study estimated the genetic diversity and genetic origin of C. mydas mixed stocks at two FGs in northeastern Colombia (Santa Marta and La Guajira), and inferred their connections to NRs groups in the Atlantic basin using mitochondrial Control Region (mtCR) as a marker. A high genetic diversity, evidenced by the high nucleotide and haplotype diversities, was found in both studied mixed stocks and may be explained by different contributing NRs groups found with mixed stock analyses (MSAs). At least three genetically distinct groups from different sides of the Atlantic Basin contributed juveniles to the mixed stocks in Colombia. Observed demographic connectivity can be explained by the confluence of two major, opposite directions ocean currents by the study area, the Caribbean Current (westward) and the Panama-Colombia Countercurrent (eastward). The high diversity of turtles at Colombia’s FGs suggests that the area is an important link in the network of habitats used by C. mydas to be considered in management and transnational conservation planning for the species recovery.
... The Gulf of Venezuela is known as an important area for recruitment and development of marine organisms (Alió, 2000). It is considered as a refuge (alongside the Caribbean coast of Colombia) due to the occurrence of cold and nutrient-rich upwelling waters (Miloslavich et al., 2010;Rueda-Roa & Muller-Karger, 2013). Filled with an enormous biotic richness (Rodríguez & Morales, 2000) it has a total of 28 species of echinoderms, representing 11.54% of the total diversity of the phylum in marine areas from the coast of Venezuela (Lodeiros et al., 2013). ...
Article
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Echinoderms are a major group of marine invertebrates that often play integral roles within the marine ecosystem. Studies about their occurrence, abundance, and distribution in Venezuela are focused in the central-eastern coasts; hence the aim of this study is to describe the echinoderm community in the north-western coast of the Gulf of Venezuela. Samples were collected from three sites in the Venezuelan Guajira Peninsula (Castilletes, Porshoure, and Kazuzain) where patchy coral reefs and seagrass meadows are abundant. According to the substrate, two methods were performed using quantitative (1 m2 quadrates), and qualitative free-diving observations. All organisms were counted and identified to the lowest possible taxonomic level; finally, diversity (Shannon diversity index), richness (number of species), and dominance in the different sampled substrates were recorded. The updated list of echinoderms of the Gulf of Venezuela reported in this research, includes 20 genera, 15 families, 10 orders, four classes, and 28 species. The richest class was Ophiuroidea, with 18 species, followed by Asteroidea, Echinoidea and Holothuroidea, with three species each. Castilletes was the sampling site with the higher number of species (18 species), followed by Porshoure (15 species), and lastly Kazuzain (12 species). Our observations indicate that the number of species and abundance were higher when found in coral reefs (21 species, 80.69% of the total collected individuals) in contrast to the species found in seagrass beds (16 species, 19.31% of the total of individuals collected). This updated list of echinoderms represents 11.54% of the total diversity of the phylum in the marine areas from the coast of Venezuela; it is suggested that this percentage is greatly influenced by the differences of habitats and substrates alongside the north-western coast in the Gulf of Venezuela.
... On the basis of data obtained from oceanographic campaigns (Andrade and Barton, 2005;Paramo et al., 2011), satellite observations (Castellanos et al., 2002;Paramo et al., 2011;Rueda-Roa and Muller-Karger, 2013), and ocean circulation models (Jouanno et al., 2009;Santos et al., 2016;Montoya-Sánchez et al., 2018b;van der Boog et al., 2019), some authors have tried to describe the atmospheric and oceanic mechanisms associated with upwelling in La Guajira. They found that its variability responds to changes in the CLLJ and to the intense submesoscale activity (mainly in the form of filaments) that develops in the area. ...
Article
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The variability of La Guajira upwelling system, in the south-central Caribbean Sea, is strongly influenced by the intensity and location of the atmospheric Caribbean Low-Level Jet (CLLJ), a near-surface branch of the easterlies, as well as by the regional ocean circulation. During favorable conditions (i.e. strong easterlies blowing almost parallel to the coast), upwelling is enhanced and a large amount of primary productivity occurs in La Guajira area. In contrast, during relatively mild wind conditions, the CLLJ is misaligned to the coast and the Caribbean Counter Current (CCC, locally also known as the Darien Current), which forms as a branch from the Panama-Colombia Gyre, flows northeastward over the continental shelf advecting waters from the southwestern Caribbean basin towards La Guajira. The CCC has a clear signature at the surface layer that extends from the Darien Gulf towards La Guajira peninsula during mild wind periods, while disappears during the months of strong winds. The direction and the magnitude of the easterlies, and more specifically of the CLLJ, control the position and pathway of the CCC, which extends more than 900 km in the southern Caribbean Sea during May, June, August, September and October. The high concentration of chlorophyll-a at the sea surface evidenced by satellite-based colour images is semi-seasonally modulated by the CLLJ, which during its relaxation phase allows the irruption of the CCC towards the east up to La Guajira
... The southern Caribbean shelf is oceanographically complex, being subject to upwelling of cool, nutrient-rich water at foci that are separated by areas free from upwelling (Tedesco & Thunell, 2003a, b;Andrade & Barton, 2005;Rueda-Roa & Muller-Karger, 2013;Wilson & Hayek, 2019). The pattern of sediment redistribution and upwelling in the southern Caribbean Sea changes seasonally with the arrival of the Trade Winds in the dry season and heavy rains in the hurricane season (Wilson, 2010), at which time the Inter-Tropical Convergence Zone (ITCZ) moves north into the area (Hoffmann et al., 2014). ...
Article
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A preliminary study of the composition and community structure of the foraminifera of Chichiriviche de La Costa (Vargas, Venezuela) is presented. A total of 105 species were found in samples from 10 to 40 meter-depth, and their abundance quantified in a carbonate prone area almost pristine in environmental conditions. The general composition varies in all the samples: at 10 m, Miliolida dominates the assemblages but, as it gets deeper, Rotaliida takes control of the general composition. The Shannon Wiener diversity index follows species richness along the depth profile, meanwhile the FORAM index has a higher value at 20 m and its lowest at 40 m. Variations in the P/(P+B) ratio and high number of rare species are documented and a correspondence multivariate analysis was performed in order to visualize the general community structure. These results could set some basic information that will be useful for management programs associated with the coral reef in Chichiriviche de La Costa, which is the principal focus for diver’s schools and tourism and could help the local communities to a better understanding of their ecosystem values at this location at Vargas State, Venezuela. Keywords: Miliolida, Rotaliida, foraminiferal assemblages, FORAM index, Caribbean continental shelf.
... Una de las razones que hace tan importante al Golfo de Venezuela para esta especie de tortuga marina son los fenómenos de surgencia que ocurren en la región oriental del mismo (Barrios-Garrido 2018). Entre la Península de Paraguaná y el suroccidente de las costas del Estado Falcón, surgen plumas de aguas frías se pueden extender hasta el centro del Golfo donde se mezclan con las aguas cálidas del Lago de Maracaibo (Rueda- Roa & Muller-Karger 2013). Este fenómeno sigue un patrón estacional donde se registra que sus picos más altos comprenden entre los meses de enero y marzo, luego van decreciendo al pasar los meses, donde el declive más mar-cado se encuentra entre los meses de junio y julio, y generalmente no está presente en los siguientes meses del año (Castellanos et al. 2002, Rueda-Roa et al. 2018. ...
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Se trata de un artículo publicado en un libro digital Intitulado Aprender a vivir para un mundo diferente. Se hace abordaje sobre un modelo didáctico centrado en el autoconocimiento que privilegie la metacognición en orden al desarrollo de habilidades cognitivas para aprender sobre las TIC y con las TIC
... Una de las razones que hace tan importante al Golfo de Venezuela para esta especie de tortuga marina son los fenómenos de surgencia que ocurren en la región oriental del mismo (Barrios-Garrido 2018). Entre la Península de Paraguaná y el suroccidente de las costas del Estado Falcón, surgen plumas de aguas frías se pueden extender hasta el centro del Golfo donde se mezclan con las aguas cálidas del Lago de Maracaibo (Rueda- Roa & Muller-Karger 2013). Este fenómeno sigue un patrón estacional donde se registra que sus picos más altos comprenden entre los meses de enero y marzo, luego van decreciendo al pasar los meses, donde el declive más mar-cado se encuentra entre los meses de junio y julio, y generalmente no está presente en los siguientes meses del año (Castellanos et al. 2002, Rueda-Roa et al. 2018. ...
... Una de las razones que hace tan importante al Golfo de Venezuela para esta especie de tortuga marina son los fenómenos de surgencia que ocurren en la región oriental del mismo (Barrios-Garrido 2018). Entre la Península de Paraguaná y el suroccidente de las costas del Estado Falcón, surgen plumas de aguas frías se pueden extender hasta el centro del Golfo donde se mezclan con las aguas cálidas del Lago de Maracaibo (Rueda- Roa & Muller-Karger 2013). Este fenómeno sigue un patrón estacional donde se registra que sus picos más altos comprenden entre los meses de enero y marzo, luego van decreciendo al pasar los meses, donde el declive más mar-cado se encuentra entre los meses de junio y julio, y generalmente no está presente en los siguientes meses del año (Castellanos et al. 2002, Rueda-Roa et al. 2018. ...
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Aborda el tema sobre los procesos de construcción del conocimiento en la comunidad de aprendizaje que conforman los estudiantes tesistas con sus orientadores o tutores.
... Una de las razones que hace tan importante al Golfo de Venezuela para esta especie de tortuga marina son los fenómenos de surgencia que ocurren en la región oriental del mismo (Barrios-Garrido 2018). Entre la Península de Paraguaná y el suroccidente de las costas del Estado Falcón, surgen plumas de aguas frías se pueden extender hasta el centro del Golfo donde se mezclan con las aguas cálidas del Lago de Maracaibo (Rueda- Roa & Muller-Karger 2013). Este fenómeno sigue un patrón estacional donde se registra que sus picos más altos comprenden entre los meses de enero y marzo, luego van decreciendo al pasar los meses, donde el declive más mar-cado se encuentra entre los meses de junio y julio, y generalmente no está presente en los siguientes meses del año (Castellanos et al. 2002, Rueda-Roa et al. 2018. ...
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La humanidad se encuentra en tiempos convulsivos, que han re�ordenado la concepción del mundo e introducen nuevos indicadores de referencia, que según Kuhn (1971), permiten captar oportunidades y delinear propósitos, es decir los cambios nos confrontan y activan, para encontrar la normalidad deseada Esto compromete la dinámica de generación de conocimiento y los cambios que la impactan actualmente, dejando la progresividad de lo planificado, que se ve afectado por situaciones aceleradas, confusas y devastadoras, dejado aprendizaje, retos y también oportunidades. De tal manera que, la sostenibilidad de la vida y el compromiso del hombre por su subsistencia y la del otro, están comprometiendo las relaciones proximales y distales propias de la generación y docu�mentación del conocimiento, lo cual hace diferenciable e imperativo, el manejo inteligente del flujo de energía que se genera, desde lo propio y lo organizacional, encontrando en la ciencia abierta cuatro aspectos que destacar: el manejo de las plataformas digitales, la generación de confianza, la construcción de espacios de concertación entre pares y cimentación de nuevas oportunidades, a través de un ciclo abierto, con retroacción: incorporan, recibir, retornar, actuar, cooperar y nutrir, para ser sostenible y útil el conocimiento en tiempos de incertidumbre. Es evidente, que las plataformas digitales en las universidades se han consolidado, como herramienta primordial de comunicación, or�ganización, visibilidad y accesibilidad del conocimiento, a través de las cuales, el investigador con su institucionalidad y experticia, logra pro�yectarse, informar y difundir información a través de congresos o cual�quier otra modalidad de compartición del conocimiento. Esto inscribe el presente texto en una concepción socio digital, que permite recopilar y documentar el conocimiento científico, a través de experiencias aca�démicas e investigaciones, que sirven de referente significativo, para aprender a vivir en un mundo diferente, donde tal diferencia delinea criterios para construir el regreso a la normalidad deseada
... GV is positioned at the upper and exterior depression of the Maracaibo System (Latitudes 9° and 12° N, and Longitudes 70°15' and 72°15' W) between Zulia and Falcon States; next to Colombia and at the Southwest of Aruba, Bonaire and Curacao Islands (FIG. 1) [27]. It has a fluctuating water dynamic, and is considered a shallow water system, with depths between 20 to 30 meters (m), temperatures from 28 to 30ºC, and salinity up to 35 practical units of salinity (UPS, by its Spanish acronym) [16,17], and with an important upwelling area [29]. Also, GV includes a variety of habitats, from sandy beaches, mangroves forests, coral reef patches to extensive, highly productive seagrass beds [25,27]. ...
Article
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Fibropapillomatosis (FP) is affecting multiple marine turtle species worldwide. In Venezuela, the understanding about this neoplastic condition is still in early stage. Hence, this paper aims to assess the occurrence and frequency of FP in green turtles (GT) in the Gulf of Venezuela (GV). Herein, it was compiled and analyzed the reports in the database of the NGO ‘Grupo de Trabajo en Tortugas Marinas del Golfo de Venezuela’, which includes all records of stranded marine turtles (MT) in the GV from 2000 to 2011. Between 2000 and 2006, in the GV only 2 cases of FP in MT had been reported (1.71% of total records). Subsequently, between 2008 and 2011, encounters of FP were more frequent; resulting in a total of 7 immature GT (2.93% of the records) documented showing large masses or skin tumors in various parts of the body. The most affected area of the MT’s body was neck and venous sinus (37.50%), followed by the anterior flippers (18.75%), plastron (18.75%), posterior region (cloaca 18.75%) and lastly, the eyes (6.25%). All individuals presented two or more body areas with FP. Although a correlation between the presence of FP and environmental factors observed in the study area was not assessed, the turtles evaluated came from coastal waters with high levels of eutrophication, habitat degradation, and pollution. It is necessary to monitor the occurrence of this disease and the environmental factors that may negatively affect the survival of MT populations in the GV.
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The effects of anthropogenic pressures in coastal areas are extensively studied in temperate but not in tropical zones, where their impact might be amplified by high water temperatures and upwelling phenomena. Sedimentary features and benthic metabolism were studied during the non upwelling (NUPW) and upwelling (UPW) seasons in Taganga Bay (Colombia). The bay is impacted by a submarine outfall of virtually untreated, organic and nutrient-rich wastewater. Samplings were performed in November 2017 (NUPW) and in January–February 2018 (UPW) at 4 stations located in the proximity and 100, 750 and 1800 m far from the outfall, respectively, at depths between 22 and 28 m. Aerobic respiration, denitrification, dissimilative nitrate reduction to ammonium (DNRA) and nutrient fluxes were measured. The influence of the outfall was detectable 750 and 1800 m away from the point pollution source, where δ13C data suggested that ~ 40 and ~ 20% of organic inputs were terrigenous, respectively. In the proximity of the outfall benthic oxygen demand peaked and the presence of Beggiatoa mats suggested reoxidation of sulphides, that were abundant in pore water. Under sulfidic conditions, DNRA was the major driver of nitrate demand, whereas at stations far from the outfall, denitrification dominated nitrate consumption. Organic matter and nitrate inputs to the bay during the UPW season enhanced the effects of the outfall by increasing aerobic respiration and DNRA. Higher N availability during the UPW season reversed fluxes of molecular nitrogen and turned the sediments of 3 out of 4 sites from net sinks to net N2 sources. Results from this study suggest that the analysis of sediments allows tracing the impact of the outfall and that such impact is enhanced during the upwelling season. In tropical areas, marine outfalls and upwelling may act in synergy and contribute to ecosystem deterioration due to high temperatures, increase of microbial respiration, sulphide toxicity and benthic biodiversity loss.
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The Gulf of Venezuela represents an important area for feeding and development of the Leatherback turtle, Dermochelys coriacea, in the southern Caribbean Sea. In order to assess potential risks associated with oil-related activities on Leatherback turtles in the Gulf of Venezuela. The present research aims to evaluate the possible risk factors that oil activities can generate on these animals, analyzing the frequencies and spatial coincidences of these threats with the critical habitats for leatherback turtles in the study area. This investigation was based on a data compilation of biological and anthropogenic available online. These records were analyzed and georeferenced. Assessed datasets are related to: (a) spatial-temporal strandings records of D. coriacea; (b) Identified zones where marine upwelling occurred (based on Sea Surface Temperature (SST); (c) High Marine Traffic areas; (d) Location of navigation channel at the south of Gulf of Venezuela; (e) Hydrocarbons pipeline location (Rio Seco-Tiguadare). All this was assessed to understand how potential threats to Leatherback turtles could be affecting or decreased the environmental quality by potential stressor agents originated by activities such as hydrocarbons transporting and refining. It is recommended to carry out field work and continue monitoring.
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The crustaceans associated with the submerged roots of Rhizophora mangle, in the Laguna de Cocinetas, Alta Guajira Venezolana, were analyzed. Two red mangrove roots were taken in six sampling stations, in June and November 2006 and in February and April 2007. The salinity, temperature, pH, transparency and depth of the water were measured in situ. 6139 crustaceans were counted in 48 roots, distributed in 30 families and 46 species. The families with the highest number of species were GRAPSIDAE (4), LIMNORIDAE (4) and XANTHIDAE (4). The tanaidaceans Leptochelia dubia (314 ind / m2 ) and Leptochelia forresti (264 ind / m2) were the crustaceans with the highest density. Peracarids (tanaidaceans and amphipods) were the most abundant crustaceans associated with the roots of R. mangle in the Cocinetas lagoon, Alta Guajira, Venezuela; however, the average density (ind / m2) of crustaceans is low, compared to other marine lagoon areas of Venezuela and the Caribbean.
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Fibropapillomatosis (FP) is affecting multiple marine turtle (MT) species worldwide. In Venezuela, the understanding about this neoplastic condition is still in early stage. Hence, this paper aims to assess the occurrence and frequency of FP in green turtles (GT) in the Gulf of Venezuela (GV). Herein, it was compiled and analyzed the reports in the database of the NGO ‘Grupo de Trabajo en Tortugas Marinas del Golfo de Venezuela’, which includes all records of stranded MT in the GV from 2000 to 2011. Between 2000 and 2006, in the GV only 2 cases of FP in MT had been reported (1.71 % of total records). Subsequently, between 2008 and 2011, encounters of FP were more frequent; resulting in a total of 7 immature GT (2.93 % of the records) documented showing large masses or skin tumors in various parts of the body. The most affected area of the MT’s body was neck and venous sinus (37.50 %), followed by the anterior flippers (18.75 %), plastron (18.75 %), posterior region (cloaca 18.75 %) and lastly, the eyes (6.25 %). All individuals presented two or more body areas with FP. Although a correlation between the presence of FP and environmental factors observed in the study area was not assessed, the turtles evaluated came from coastal waters with high levels of eutrophication, habitat degradation, and pollution. It is necessary to monitor the occurrence of this disease and the environmental factors that may negatively affect the survival of MT populations in the GV.
Article
Marine turtles are challenging species to protect because they occur over large geographic scales. Tagging individual turtles at nesting beaches and foraging areas, and the resulting mark-recapture data sets have gradually enabled us to understand their migratory behaviour and dispersal. Within the Caribbean region, several turtle tagging projects have led to longer-term evaluations and assessments of connectivity. Thus, the turtle mark-recapture data is important for developing conservation strategies at regional-scale. In this study, we analyse turtle tagging data from the Gulf of Venezuela to determine regional (Caribbean and Atlantic geographic level) and local (within the Gulf of Venezuela) links. To achieve this, we retrieved, compiled, and analysed multiple databases with records of marine turtles that were tagged and then recaptured in the Gulf of Venezuela. Sixty-six tag return records were evaluated, 43 from animals initially tagged outside of the Gulf of Venezuela and then recaptured inside, plus 23 records retrieved from turtles that were tagged and recaptured within the Gulf of Venezuela. We found evidence of connectivity between 12 different locations where initial tagging events occurred, eight from other feeding areas and four from nesting beaches. We described four different movement patterns for 23 turtles tagged and re-captured within the Gulf of Venezuela. Most of the recapture records we obtained occurred after the turtles were known, or presumed, to have been killed by local fishers. Hence, knowing patterns of dispersal and connectivity are crucial to improving local and regional conservation and threat mitigation.
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The ecostratigraphy of offshore North Coast of Trinidad and near Tobago is poorly resolved, although biogenic gas production for which it would be useful is widespread. Recent work has shown that a wake and eddy in the Guiana Current and Orinoco Plume to the lee of NW Tobago influence benthic foraminiferal assemblages. This ecostratigraphical study of planktonic foraminiferal assemblages examines three piston cores taken on the lee of NW Tobago. Core 1 (upper bathyal) was most distal to the nutrient-rich Orinoco Plume and Core 3 (outer neritic) the most proximal. The assemblage turnover index (ATI) and analysis of variance (ANOVA) determined that the relative community stability at each site did not differ, showing similar community stabilities within the wake and plume. However, an abnormally high abundance of the deep-dwelling, nutrient-loving Globorotalia truncatulinoides dextral in Core 2 indicated an oceanographic boundary between Cores 1 and 2 along which the Orinoco Plume abuts the oligotrophic ocean. This is reflected in the distributions of other planktonic foraminiferal morphotypes such as G. bulloides, Gn. obesa and G. ruber pink. SHE analysis detected two biozones in Cores 2 and 3, possibly marking a change in nutrient influx. Principal component analysis reinforced the nutrient influx as a major factor acting at Cores 2 and 3 in the wake and Orinoco Plume, Core 2 being seasonally impacted while Core 3 lies permanently within the Orinoco Plume. We conclude that oceanographic complexity off NW Tobago affects the distributions of planktonic foraminiferal morphotypes at the kilometer scale. Our results will prove to be a powerful tool in deciphering the geological history of the Orinoco Plume.
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RESUMEN: Los patrones de presencia de micromoluscos han sido generalmente usados como indicadores idóneos de condiciones en la fauna de sedimentos y potenciales presas de depredadores bentófagos, siendo los de la familia Caecidae raramente encontrados como presa de peces planctófagos. Se realizaron muestreos mensuales del zooplancton utilizando una red estándar de 300 micras con calados superficiales, para el registro de presas de peces filtradores capturados con arrastres costeros, para ser usados en el estudio del contenido gastrointestinal del tinícalo Atherinella (= Xenomelaniris) brasiliensis (Pisces: Atherinidae) identificando bajo microscopio estereoscópico la frecuencia de presas. Una revisión de la familia Caecidae mostró para Venezuela la presencia de 8 especies, donde comúnmente están presentes Caecum. floridanum, C. nitudum, siendo también C. pulchellum de común presencia. Se realizó una identificación de C. pulchellum, especie común en sedimentos extra plataforma y litoral, en componente del plancton y dentro de los ítems alimentarios de la especie estudiada. Para el ejemplar planctónico se observaron medidas de 1,72 mm de largo y 0,38 mm de ancho formando parte del zooplancton litoral. Para los análisis de contenido estomacal, se registró un ejemplar en buen estado con las medidas de 1,73 mm de largo y 0,47 mm de ancho, observándose presencia de un opérculo circular con líneas concéntricas. Lo somero del área de estudio, nos indica que la presencia de estos organismos en el plancton puede deberse a la alta turbulencia producida por el oleaje, donde formaría parte del pseudoplancton. La dieta de A. brasiliensis incluyó organismos planctónicos no comunes donde C. pulchellum ocurre en un 2,63% de frecuencia alimentaria. No obstante, la presencia no permanente, sugiere ser un ítem incidental como parte de la trama trófica de las costas litorales del país. Palabras claves: Caecidae, Zooplancton, Contenido estomacal. ABSTRACT: Micromollusc patterns have been generally used as ideal indicators of sediment fauna and potential preys of benthic predators, with the family Caecidae being rarely found as prey to planktivorous fishes. Monthly zooplankton sampling was carried out using a standard plankton net of 300 microns with surface trawls for recording fish filtered preys with coastal trawls, to be used in gastrointestinal content studies in Silverside Atherinella (=Xenomelaniris) brasiliensis (Pisces: Atherinidae) in order to identifying under stereoscopic microscopy prey frequency. A review of the Caecidae family showed the presence of 8 species in venezuelan waters, where Caecum floridanum, C. nitudum and C. pulchellum are commonly present. A registered identification of C. pulchellum, a common species at offshore and littoral sediments, was made as a component of plankton and within the food items of the species studied. The planktonic specimen measurements were 1.72 mm long and 0.38 mm wide observed as part of the littoral zooplankton. In the analysis of stomach contents, a specimen was recorded in good condition with the measurements of 1.73 mm length and 0.47 mm width, observing the presence of a circular operculum and concentric lines. The shallow water conditions at the study area indicates that the presence of these organisms in plankton may be due to high turbulence produced by waves, where it would form part of pseudoplankton. The diet of A. brasiliensis included uncommon planktonic organisms where C. pulchellum occurs with a 2.63% food frequency. Non-permanent presence, however, suggests being an incidental item as part of the trophic web of the venezuelan littoral coasts.
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Understanding how emergent ecological assemblages have diverged from natural states is fundamental in predicting future functioning and services of ecosystems. Coral reefs are of particular concern due to their high susceptibility to anthropogenic stressors. Yet, little is known about their pre-disturbance ranges of natural states, and most reports of decline are based on a limited number of sites and high levels of uncertainty. Here, we used a novel approach to estimate the physical functionality of reefs across marine ecoregions based on habitat suitability and morpho-functional traits for coral species. We calibrated ecological niche models for 49 reef-building corals of the Greater Caribbean based on occurrence records and environmental predictors, which we combined with species-specific functional coefficients derived from morpho-functional traits reflecting their contribution to the reef three-dimensional structure to estimate the reef functional potential (RFP). We then assessed the degree of divergence of western Caribbean reefs by comparing our physical functionality estimates against recent field data evaluations. We found spatial variability in RFP across the Caribbean, with the highest mean value in the western Caribbean and the lowest in areas with marginal environmental conditions. Hotspots of RFP exist along the coast of Belize and the southeast of Cuba. Overall, 84% of sites along the western Caribbean showed a substantial reduction in their physical functioning, with the highest reductions occurring within hotspots, implying that reefs displaying the greatest changes have high initial RFP. We conclude that combining niche models with species morpho-functional traits is a valuable and promising approach to estimate the large-scale functional potential of communities and the degree of change in the absence of ecological baselines. These findings have important implications and could be used to guide efforts to preserve coral reefs functionality and define priority conservation areas in the Caribbean.
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Understanding how emergent ecological assemblages have diverged from natural states is fundamental in predicting future functioning and services of ecosystems. Coral reefs are of particular concern due to their high susceptibility to anthropogenic stressors. Yet, little is known about their pre-disturbance ranges of natural states, and most reports of decline are based on a limited number of sites and high levels of uncertainty. Here, we used a novel approach to estimate the physical functionality of reefs across marine ecoregions based on habitat suitability and morpho-functional traits for coral species. We calibrated ecological niche models for 49 reef-building corals of the Greater Caribbean based on occurrence records and environmental predictors, which we combined with species-specific functional coefficients derived from morpho-functional traits reflecting their contribution to the reef three-dimensional structure to estimate the reef functional potential (RFP). We then assessed the degree of divergence of western Caribbean reefs by comparing our physical functionality estimates against recent field data evaluations. We found spatial variability in RFP across the Caribbean, with the highest mean value in the western Caribbean and the lowest in areas with marginal environmental conditions. Hotspots of RFP exist along the coast of Belize and the southeast of Cuba. Overall, 84% of sites along the western Caribbean showed a substantial reduction in their physical functioning, with the highest reductions occurring within hotspots, implying that reefs displaying the greatest changes have high initial RFP. We conclude that combining niche models with species morpho-functional traits is a valuable and promising approach to estimate the large-scale functional potential of communities and the degree of change in the absence of ecological baselines. These findings have important implications and could be used to guide efforts to preserve coral reefs functionality and define priority conservation areas in the Caribbean.
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The Gulf of Venezuela represents an important area for feeding and development of the Leather- back turtle, Dermochelys coriacea, in the southern Caribbean Sea. In order to assess potential risks associated with oil-related activities on Leather- back turtles in the Gulf of Venezuela. The present research aims to evaluate the possible risk factors that oil activities can generate on these animals, analyzing the frequencies and spatial coincidences of these threats with the critical habitats for lea- therback turtles in the study area. This investiga- tion was based on a data compilation of biological and anthropogenic available online. These records were analyzed and georeferenced. Assessed data- sets are related to: (a) spatial-temporal strandings records of D. coriacea; (b) Identified zones where marine upwelling occurred (based on Sea Surface Temperature (SST); (c) High Marine Traffic areas; (d) Location of navigation channel at the south of Gulf of Venezuela; (e) Hydrocarbons pipeline loca- tion (Rio Seco-Tiguadare). All this was assessed to understand how potential threats to Leatherback turtles could be affecting or decreased the environ- mental quality by potential stressor agents origina- ted by activities such as hydrocarbons transporting and refining. It is recommended to carry out field work and continue monitoring.
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The Gulf of Venezuela represents an important area for feeding and development of the Leatherback turtle, Dermochelys coriacea, in the southern Caribbean Sea. In this feeding area there are a vast spatial-temporal records of strandings of juveniles and adults. These strandings increase among the months of February-March, and August-September, which coincide with the pre and post-reproductive migrations interval times in the Caribbean Sea. In order to assess potential risks associated with oil-related activities on Leatherback turtles in the Gulf of Venezuela. This investigation was based on a data compilation of biological and anthropogenic available online. These records were analyzed and georeferenced. Assessed datasets are related to: (a) spatialtemporal strandings records of D. coriacea; (b) Identified zones where marine upwelling occurred (based on Sea Surface Temperature (SST); (c) High Marine Traffic areas; (d) Location of navigation channel at the south of Gulf of Venezuela; (e) Hydrocarbons pipeline location (Rio Seco-Tiguadare). All this was assessed to understand how potential threats to Leatherback turtles could be affecting or decreased the environmental quality by potential stressor agents originated by activities such as hydrocarbons transporting and refining. This affectation would vary in terms of distance among upwelling areas and stressors’ intensity, as well as, seasonal period of the year which could occurred. Although the present investigation seeks for analyzing possible stages of interaction among Leatherback turtles and anthropogenic threats, it is necessary confirming this finding with direct observations. This investigation aims of setting theoretical bases for a framework in order to create a constant monitoring through remote sensors of biological events (migratory patterns and upwelling) and alterations in the marine-coastal habitat of the Gulf of Venezuela.
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In Tayrona National Natural Park (Colombian Caribbean), abiotic factors such as light intensity, water temperature, and nutrient availability are subjected to high temporal variability due to seasonal coastal upwelling. These factors are major drivers controlling coral reef primary production. This offers the opportunity to assess the effects of abiotic factors on key coral reef ecosystem services in terms of productivity. We therefore quantified primary net ( P n ) and gross production ( P g ) of the dominant local primary producers (scleractinian corals, macroalgae, algal turfs, crustose coralline algae, and microphytobenthos) at a water current/wave-exposed (EXP) and -sheltered (SHE) site in an exemplary bay of Tayrona National Natural Park. A series of short-term incubations was conducted to quantify O 2 fluxes of the different primary producers before and at the end of the upwelling event 2011/2012. At the level of the organism, scleractinian corals showed highest P n and P g rates before upwelling (16 and 19 mmol O 2 m ⁻² specimen area h ⁻¹ ), and corals and algal turfs dominated the primary production at the end of upwelling (12 and 19 mmol O 2 m ⁻² specimen area h ⁻¹ , respectively). At the ecosystem level, corals contributed most to total P n (EXP: 81 %; SHE: 65 %) and P g (EXP: 78 %; SHE: 55 %) before the upwelling, while at the end of the upwelling, corals contributed most to P n and P g only at EXP (73 and 75 %) and macroalgae at SHE (52 and 46 %, respectively). Despite the significant spatial and temporal differences in individual productivity of investigated groups and their different contribution to reef productivity, no spatial or temporal differences in daily ecosystem P n and P g were detected (194 – 218 and 311 – 409 mmol O 2 m ⁻² seafloor area d ⁻¹ ). Our findings therefore indicate that local autotrophic benthic reef communities are well adapted to pronounced fluctuations of environmental key parameters. This might lead to a higher resilience against climate change consequences and anthropogenic disturbances.
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The morphological, phenological and ecological characteristics of shallow coral reefs have been widely studied, but only recently have mesophotic corals begun to be studied. Very little is known about these ecosystems and their associated communities, such as the zooplankton community, which constitutes a food source for reefs and for the organisms that inhabit them. In the present study, changes in zooplankton composition were characterised during two hydroclimatic periods in a mesophotic environment of the submarine mountain Bajo Frijol, in Corales de Profundidad National Natural Park, Colombia. Zooplankton was collected using a portable pumping device, which contained three collectors of differing mesh sizes; this allowed the capture of zooplankton ranging in size from 45 to 300 μm. Temperature, conductivity, oxygen and pH were obtained and complemented with MODIS AQUA satellite information. In this ecosystem, the zooplankton organisms with the greatest richness and abundance were small-sized copepods, radiolarians and tintinnids. The oceanography of the area results in greater zooplankton abundance, richness, and diversity in June when the coastal current allows greater chlorophyll-a concentrations in the area and smaller organisms are favoured by greater retention within the corals of the mesophotic system. The biodiversity reported for Bajo Frijol is the first detailed approach to the community of mesophotic coral reefs in the Colombian Caribbean Sea, contributing to new records to the Global Biodiversity Information Facility.
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Flooding episodes occur frequently in the Colombian Caribbean and cause damage to coastal settlements. However, there is little knowledge about these episodes and about how changes in associated variables affect coastal flooding. This paper presents the results obtained from analyzing the temporal variability of flood levels in Moñitos-Córdoba on the Colombian Caribbean coast, as well as the contribution their components make to different time scales. To achieve this, the total sea level was estimated indirectly as the sum of the variables involved (sea level anomalies, astronomical tide, meteorological tide and wave runup). These variables were obtained by applying numerical and empirical modeling using satellite altimetry data, tidal modeled data and wind, waves and atmospheric pressure from reanalysis. Data Trends and contributions were analyzed using statistical methods, including variance analysis, exceedance distributions, linear regressions, Sen-Slope and the Mann Kendall test. The results indicate that the total sea level has a semi-annual cycle with its highest maximum levels in the months of December to March and its lowest maximum levels in the months of April and September. The total sea level variability in Moñitos is dominated by the run-up component at short-term scales (monthly, intra-annual and inter-annual), while at longer-term timescales (>2 years) variability is dominated by the mean sea level component. Runup is the greatest contributor to the flood level, followed by the mean sea level in average conditions and the astronomical tide in extreme conditions. There was a trend of increasing total sea level, related to the trend in altimetric sea level, with a consequent increasing trend of frequency and magnitude of extreme levels of flooding.
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Bivalve sclerochronological records with annually resolved growth bands are applicable proxies in reconstructing features of the hydro-climate system. Here we evaluate the relationship between growth indices of A. islandica, previously collected at approximately 82 m depth in the North Atlantic, and seasonal subsurface temperature at various depths for the 1900–2005 period. Correlations with sea surface temperature at the collection site are not significant during winter and weak for the remaining seasons. The strongest in-phase correlations persist for summer and autumn below 56 m water depth, whereas weaker correlations are lagged by one or two years. We also observe similarities with distant water bodies in the North Atlantic sector, and a corresponding large-scale oceanographic pattern that increases significantly with water depth along the trajectory of the North Atlantic Current. We suggest that by investigating the relationship with the temperature signal at various depths locally and at large-scale increases the reliability and application of bivalve shells as marine archives.
Poster
The Southern Caribbean Upwelling System (SCUS, 75-62ºW and 10.5-16ºN) is a tropical coastal upwelling whose contribution to the surface water masses, ecology and economy of the Caribbean is not completely known. Analyzes based on upwelling indices calculated from the wind (UIw), have shown the SCUS variability associated with regional changes in wind intensity, the coastline orientation and zonal differences in the thermal stratification of the water column. Due to the low latitude and high stratification in the SCUS, UIw do not allow a correct estimation of the volume of upwelled water in the system and its offshore advection to other areas of the Caribbean. This work analyzes the variability and extent of the SCUS, using satellite and modeled information of winds, sea surface temperature and chlorophyll. The SCUS variability is studied using upwelling indices that integrate wind and temperature data (UIwt), while its extension is estimated from the position of upwelling fronts. The results shown that the UIw overestimates the upwelling intensity mainly in the western sector (75-70ºW) of the SCUS. The seasonal and intra-seasonal variability of the SCUS observed through UIwt is not always coupled to atmospheric forcing, which suggests an upwelling modulation by internal waves of the Caribbean Sea. The interannual variability show frequencies associated with ENSO fluctuations that alter the intensity and the extension of the system in the long term. The extent of the SCUS (determined by the position of the temperature front) was greater in the western (280.7 ± 161.2 km) than in the eastern region (259.3 ± 134.8 km) of the system, reaching many offshore ecosystems of the insular Caribbean. However, the extension of the high biological productivity area (determined by the position of the chlorophyll front) was ~60% less than that of the upwelled waters (temperature front) in both regions, therefore, the contribution of upwelling nutrients for ocean ecosystems could be less than for coastal ecosystems. Despite this, the extension and intensity of upwelling in the SCUS may be the main mechanism to maintain biological productivity in the Caribbean.
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Between January 23rd and 27th, 2020, a Fin whale (Balaenoptera physalus) was seen in coastal waters of the Rosario and San Bernardo Corals National Natural Park. This is the first known record of a live animal for the Colombian Caribbean Sea. While it was not possible to establish causality relationships, the present note includes a description of the environmental and oceanographic context associated with sightings. While the Colombian Caribbean, because of its oligotrophy, would not permanently sustain a constant presence of the great baleen whales, its inclusion as part of the potential distribution range for Fin whales is suggested. The current report also highlights the importance and relevance of citizen science, in addition to interinstitutional and collaborative work, key processes for the monitoring of high mobility species such as marine mammals.
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En el Caribe sur se presentan dos áreas principales de surgencia, la Guajira colombiana y el oriente de Venezuela; sin embargo, la producción pesquera es muy desigual, a pesar de que en la Guajira la intensidad del viento es mayor y teóricamente la surgencia es más intensa. Por esta razón,cual debería tener una producción pesquera mayor que la venezolana, lo que no ocurre. Se plantean las posibles causas de esta diferencia notable y se comentan aspectos relacionados con el viento, la hidrografía, la concentración de nutrientes, la biomasa del fitoplancton, la plataforma continental, el aporte de ríos, la presencia de islas y otros factores. El oriente de Venezuela tiene mayor fertilidad y producción pesquera porque la masa de agua subsuperficial subtropical es la que abastece la surgencia durante los primeros meses del año (sequía). En el segundo semestre, cuando la surgencia se relaja, el área se enriquece con materia orgánica del río Orinoco y el aporte de biomasa fitoplanctónica proveniente de lagunas costeras, golfos y bahías semicerradas. También juega un papel fundamental la amplitud de la plataforma continental con la presencia de archipiélagos, islas mayores y menores que causan enriquecimientos locales y la concentración y retención del plancton. Esto último aumenta la productividad biológica y propicia la reproducción de los organismos. En la Guajira, la surgencia podría estar influenciada por la contracorriente del Darién, que por su origen debe contener baja concentración de nutrientes inorgánicos; además, en esta zona no están presentes grandes ríos que aporten materia orgánica y la plataforma continental es poco amplia y no contiene islas que propicien el aumento de la productividad acuática. Para la comprensión de la surgencia en la Guajira, se sugieren estudios para el seguimiento in situ de la hidrografía, nutrientes inorgánicos, clorofila y la abundancia de fito y zooplancton.
Article
The SE Caribbean Sea is not ubiquitously oligotrophic. It is subject to the Caribbean Current, which is an extension of the Guiana Current and flows NW across the sea. It is also impacted by outflow from the Orinoco River, which produces a hypopycnal plume that is transported across the sea by the Caribbean Current, and by local upwelling, which occurs at distinct focuses. This paper uses non-metric multidimensional scaling (NMDS) to examine the impact of this oceanographic complexity on the distributions, based on species presence/absence, of neritic to upper bathyal benthic foraminifera. Sites within the ambit of the Orinoco Plume (Orinoco offshore , Trinidad East Coast Marine Area [ECMA], Trinidad North Coast Marine Area [NCMA), offshore NW Tobago, Bequia) are closely grouped by NMDS, despite the NCMA being subject to minor upwelling and Bequia only seasonally laying within the plume. The Paria and Araya Peninsula areas, though geographically close and both subject to upwelling, do not cluster closely. This indicates that the two upwelling focuses induced some biogeographic separation. The Isla La Tortuga, being bathed with oligotrophic water, plotted far from the eutrophic Orinoco Plume sites. The upwelling Paria Peninsula site, adjacent to the Orinoco Plume, yielded seventeen species of Bolivina (the greatest species richness for this genus of any of our sites), whereas Isla La Tortuga yielded only four. The Trinidad NCMA, likewise a site of upwelling, presented the second highest number of species of Bolivina, yielding twelve. That the Plataforma Deltana site plotted far from all others reflects its bathyal position beyond the Orinoco Plume.
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Antecedentes: Las praderas de Thalassia testudinum constituyen un ecosistema productivo y biodiverso, especialmente en la región del Caribe, donde los estudios se han enfocado principalmente en evaluar organismos de interés comercial. Objetivo: Identificar la fauna macrobentónica asociada a praderas de T. testudinum y describir sus cambios espacio-temporales en relación a los parámetros físico-biológicos y características granulométricas del sedimento. Materiales y métodos: Los muestreos se efectuaron bimestralmente (enero-noviembre de 2017), en el eje costero del complejo lagunar Chacopata-Bocaripo. Se tomaron registros de temperatura, salinidad, clorofila a y seston total, así como las características granulométricas y niveles de materia orgánica del sedimento. Los organismos recolectados fueron identificados, cuantificados y pesados. Resultados: Los parámetros ambientales no mostraron variaciones espacio-temporales. En el sedimento predominaron arenas finas, muy finas y limosas, sin variabilidad espacial y con cambios temporales a partir de mayo hasta noviembre. La materia orgánica fue mayor al 7%, con tendencia al aumento en el tiempo e igual comportamiento en todas las estaciones. Se recolectaron 2 412 organismos, distribuidos en seis Phyla, 56 familias y 105 especies. Los moluscos fueron el grupo dominante, siendo los gasterópodos Engoniophus unicinctus y Bulla striata, los más constantes. La estructura comunitaria de la pradera evaluada mostró diferencias temporales, sin cambios entre las estaciones de muestreo. Discusión: Las diferencias en la estructura comunitaria, estuvieron relacionadas con cambios en los porcentajes de arenas finas, muy finas y limosas, niveles de clorofila a y materia orgánica. Conclusiones: Los procesos hidrodinámicos y el flujo de nutrientes producidos en el complejo lagunar Chacopata-Bocaripo, estarían modulando las variaciones espacio-temporales de la fauna macrobentónica asociada a T. testudinum, influyendo directamente en las características físico-biológicas y granulométricas de la zona estudiada.
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Este capítulo realiza una revisión de indicadores para el análisis del estado del conocimiento de los recursos marinos y costeros de Colombia
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The productive waters of the Guajira peninsula (Colombia) support unique marine ecosystems and fisheries with high levels of biodiversity upon which Wayuu indigenous communities rely for subsistence. However, climate change has affected local people’s livelihoods and dependence on fisheries has increased as a result in this area. Socio-ecological knowledge to understand the fisheries and the ecosystems of Guajira is necessary, however, acquiring such knowledge has been difficult in the past due to the remoteness and harsh environmental conditions of the peninsula that hinder corresponding scientific studies. In this study, we contacted local fishermen during a field expedition of three weeks, to collect their traditional ecological knowledge (TEK) about the local marine species, particularly of sea turtles, as well as the fisheries characteristics in eastern Guajira. Fishing practices in eastern Guajira were artisanal, for subsistence, from small wooden or fiberglass vessels. The types of fishing gear varied, the most common of which were chinchorros and entanglement nets. Catch included diverse taxonomic groups such as finned fish, cartilaginous fish, sea turtles and crustaceans. Four sea turtle species occurred at eastern Guajira, the most common of which is the green sea turtle, Chelonia mydas. The sea turtles were mostly juveniles and subadults of both sexes, present year-round and with a peak in the months of May through September. After confirming the accuracy of collected TEK through field observations, we concluded these findings add knowledge to and can support fisheries and biodiversity management in Guajira, particularly in the face of regional climate-imposed challenges to human communities and marine ecosystems.
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The particles in the sea have an organic or inorganic origin, and sediment towards deep waters and the bottom; factor that maintains life in the dark ocean and process that sequesters C from the hydrosphere and atmosphere. In the Cariaco Basin site with high biological productivity and deep anoxic waters, an array of sediment traps was maintained for 20 years. The results of the particle flux between 225 to 1210 m depth were updated, measuring the basic components, organic C, N, opal (biogenic silica), carbonates (CaCO3) and terrigenous (fraction of lithogenic origin). The flux was related to the climatic and hydrographic conditions. The variations were notable, both seasonal and long-term. Although the total flux did not show significant trends in the time series, the proportions of the organic carbon (Corg,), nitrogen (N) and opal components decreased over time, while calcium carbonate (CaCO3) and terrigenous materials increased, reflecting changes in the composition of phytoplankton as the bulk origin of organic matter. There was a general positive correlation of Corg, N, and opal flux with primary production and chlorophyll at the surface, although in the upwelling season there was no correlation due to a higher recycling rate of organic matter. Zooplankton had influence on transport to anoxic deep water. Near the bottom in Cariaco comes a flux of particulate matter of 9.32 ± 5.47 g m-2 month-1 of which 0.82 ± 0.35 g m-2 month-1 is Corg, which represents 2.37% ± 1% of the C fixed on the surface.
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All major mountain ranges are assumed to have been subject to increased uplifting processes during the late Miocene and Pliocene. Previous work has demonstrated that African uplift is an important element to explain Benguela upper-ocean cooling in the late Miocene–Pliocene. According to proxy records, a surface ocean cooling also occurred in other eastern boundary upwelling regions during the late Neogene. Here we investigate a set of sensitivity experiments altering topography in major mountain regions (Andes, North American Cordillera, and southern and East African mountains) separately with regard to the potential impact on the intensity of near-coastal low-level winds, Ekman transport and Ekman pumping, and upper-ocean cooling. The simulations show that mountain uplift is important for upper-ocean temperature evolution in the area of eastern boundary currents. The impact is primarily on the atmospheric circulation which is then acting on upper-ocean temperatures through changes in strengths of upwelling, horizontal heat advection and surface heat fluxes. Different atmosphere–ocean feedbacks additionally alter the sea surface temperature response to uplift. The relative importance of the different feedback mechanisms depends on the region, but it is most likely also influenced by model and model resolution.
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A new compilation of Lagrangian velocity observations describes the state of the North Atlantic surface circulation during the 1990s. Gridded fields of velocity and eddy kinetic energy (EKE) are constructed from trajectories of more than 1500 15-m drogued satellite-tracked surface drifters in service between January 1990 and December 1999. This time period overlaps a coordinated field study of circulation and variability in the North Atlantic completed between 1996–2000 as part of the World Ocean Circulation Experiment. We describe the construction of a self-consistent drifter climatology, present decadal-mean quasi-Eulerian velocity and EKE fields computed on a 1° grid, and compare these results with contemporary satellite measurements. Detailed discussion of the inferred surface circulation is focused on three regions: (1) The Gulf Stream and North Atlantic Current, (2) the Labrador Sea and subpolar gyre, and (3) the Caribbean Sea. The swiftest drifter motions were found in the equatorial region and along the tropical, subtropical, and subpolar western boundaries. The maximum instantaneous speed determined from a single (quality-controlled and filtered) drifter observation was 273 cm s−1 in the Gulf Stream southeast of Cape Cod. The highest EKE value in the North Atlantic (2790 cm2 s−2) was found in the Gulf Stream just downstream of the New England Seamounts. Over most of the Atlantic basin, drifter-derived EKE values were found to be O(100 cm2 s−2) higher than corresponding values derived from satellite altimetry. In the Labrador Sea a region of sharply elevated EKE appears to be geographically related to the localized ejection of drifters (and by extension, mass and kinetic energy) from the energetic West Greenland Current between 60° and 62°N. When compared to drifter measurements made in the late 1970s our results suggest (but do not statistically confirm) an enhancement and slight northward shift of the zonal Gulf Stream extension. Such a shift is consistent in sign with expectations based on observed interdecadal variations in wind stress and subtropical gyre potential energy associated with the North Atlantic Oscillation.
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