Construcción del segundo puente sobre la Laguna de la Restinga, Isla de Margarita, Venezuela: Conflictos socio-ambientales y primeros impactos ecosistémicos | Construction of the second bridge over La Restinga Lagoon, Margarita Island, Venezuela: socio-environmental conflicts and first ecosystem impacts

En noviembre de 2013 se inició la construcción del segundo puente sobre la laguna de La Restinga, una obra que busca potenciar el transporte hacia la Península de Macanao. A partir de entonces, se generó un conflicto entre las autoridades gubernamentales proponentes de la obra y estudiantes e investigadores de la Universidad de Oriente, quienes exigían la presentación del Estudio de Impacto Ambiental y Sociocultural (EIAS) contemplado en la legislación ambiental venezolana. El 13 de agosto del 2014 las autoridades gubernamentales presentaron públicamente el EIAS, e indicaron que el único impacto negativo sería la tala de 1.241 m2 de mangle. No obstante, en este trabajo se demuestra que los impactos ambientales fueron mayores al indicado por las autoridades. Para ello, se utilizaron imágenes satelitales para calcular el área de manglar deforestada y otros cambios en los componentes del paisaje. También se colocaron trampas de sedimentos en el canal principal para evaluar el aporte de material exógeno a la laguna. Se pudo identificar que se talaron 2.399 m2 de manglar, se invadieron 892 m2 del canal principal con material gravoso-arcilloso y 639 m2 de las albuferas adyacentes. La sedimentación fue homogénea durante el período de estudio, pero ocurre principalmente en la zona de la obra, cuadruplicando la sedimentación en otras zonas de la boca de la laguna. Se recomienda evaluar por tiempo prolongado el transporte de sedimentos, así como el estado de salud y sobrevivencia de los manglares y organismos marinos susceptibles a la sedimentación, especialmente organismos filtradores.Palabras claves: Sedimentación, manglares, lagunas costeras, deforestación, contaminación, RAMSAR, áreas protegidas. ABSTRACT In november 2013 the construction of the second bridge over La Restinga lagoon was initiated, a work that seeks to boost transportation to the Macanao Peninsula. Thereafter, a conflict was generated between governmental authorities that proposed this construction, and students and teachers from Universidad de Oriente who demanded the submission of the Environmental and Sociocultural Impact Assessment (ESIA) required by the Venezuelan environmental legislation. On august 13th, 2014, the Governmental authorities publicly presented the ESIA, and indicated that the only negative impact would be the deforestation of 1241 m2 of mangroves. However, this study shows that the environmental impacts were greater than those indicated by authorities. To support this, satellite images were used to calculate the deforested area and to find out other changes in the components of the landscape. Sediment traps were also placed in the main channel to assess the contribution of exogenous material into the lagoon. It was estimated that the deforestation of mangroves comprised an area of 2399 m2, 892 m2 of the main channel were invaded by gravel-clay material and 639 m2 in the adjacent lagoons. Sedimentation was homogeneous during the study period, but occurred mainly in the construction area and on occasions was greater in other zones at the mouth of the lagoon. It is recommended a long-term sediment transport evaluation be performed, as well as the monitoring of the health and survival of mangroves and marine organisms susceptible to sedimentation, especially of filter feeders.Key words: Sedimentation, mangroves, coastal lagoons, deforestation, pollution, RAMSAR, protected areas

Cold temperature tolerance of the alien Indo-Pacific damselfish Neopomacentrus cyanomos from the Southern Gulf of Mexico

The abundance of the alien, Indo-Pacific damselfish Neopomacentrus cyanomos on an oil-loading platform in the southwest Gulf of Mexico indicates that widely distributed platforms could facilitate the expansion of its geo- graphic range across the western and northern fringes of the Gulf. From there it likely will spread to other areas of the Greater Caribbean. The lionfish example demonstrates that it eventually happens, and can do so rapidly. Reduced temperature effects on the physiology of this species were examined to better predict its survivability in the northern Gulf during winter, when sea surface temperatures fall as low as 15 °C along the coast. Overall, our results show that when the degree of experimental temperature decline was large and rapid, no compensation occurred and the stress response observed mostly reflected cellular processes that minimized damage. Integrated biomarker response values were significantly different between fish rapidly exposed to colder vs. warmer temperatures (declines of −4 °C each day, from 26 to 14 °C), reflected in higher values of blood metabolites and routine metabolic rates observed in fish exposed to 14 and 18 °C respectively, and lower activity of all enzymes, lower protein carbonylation, and higher oxidative damage to lipids in fish exposed to 14 °C. While the phy- siological proxies responded to minimize damage during the rapid-decrease experiment, the same proxies re- flected the consequences of compensation when fish were thermally challenged after a 45 days acclimation at 18 °C. In this case, lower values of blood metabolites and high antioxidant levels and indicators of damages underpinned its pejus lower range. Based on the results of the present work, it seems clear that low winter SSTs in the northern Gulf will slow down the colonization of the inshore area of N. cyanomos. We suggest that the use of physiological cellular stress markers on specimens acquired at the beginning of an invasion should be im- plemented in new standardized experimental protocols, including both rapid increases/decreases of temperature and post-acclimation temperature challenges, to assess the invasiveness potential of aquatic species such as this

Diversidad mitocondrial en el nor-occidente de venezuela. implicaciones para probables rutas migratorias prehispánicas

RESUMEN La utilidad del ADN mitocondrial (ADNmt) para determinar afinidad genética entre grupos indígenas contemporáneos e inferir sobre migraciones, ha sido demostrada; pero la imposibilidad de estudiar grupos prehispánicos extintos, limita las inferencias sobre migraciones en esa época. El mestizaje en poblaciones neoamericanas ha sido caracterizado por uniones entre hombres europeos y mujeres indígenas, permitiendo detectar en la población contemporánea haplogrupos mitocondriales amerindios que informan sobre poblaciones extintas. Para conocer los linajes femeninos en el occidente de Venezuela, se estudiaron los haplogrupos del ADNmt a partir de RFLP, en una muestra de 193 individuos con antepasados procedentes del occidente de Venezuela, 81 del Estado Lara (Barquisimeto) y 112 de tres pueblos del Estado Falcón (Macu-quita=25, Macanillas=29 y Churuguara=58). Se comparó la distribución de haplogrupos entre las poblaciones y se estimó el mestizaje por línea femenina en ellas. Se comparó la distribución de cuatro haplogrupos indígenas con otras regiones de América. Se observa que en las cuatro poblaciones predominan haplogrupos amerindios, seguidos de los africanos. Al comparar la fracción indígena con el resto de América encontramos que Macanillas, Lara y Churuguara se asemejan a grupos de Amazonas y Suramérica, mientras que Macuquita a Aruba. Esto sugiere una diversidad genética importante en esa zona como probable ruta de paso hacia el sur y el Caribe; además refleja vínculos genéticos importantes entre grupos prehispánicos de Aruba y los de la Península de Paraguaná. Evidencias arqueológicas soportan estos postulados. Se recomienda aumentar la muestra y realizar análisis de secuencias para un nivel mayor de precisión. Palabras clave: ADN mitocondrial, haplogrupos, población venezolana, grupos indígenas. ABSTRACT Mitocondrial DNA (mtDNA) has been widely used to study genetic relationships between contemporary Amerindian groups and to infer ancestral migration movements; however inferences about migration routes of prehispanic extinct groups are difficult. Admixture of Neoamerican groups has been characterized by unions between European males and Amerindian females. This allows the identification in present populations of Amerindian mitocondrial haplogroups which give information on ancestral groups. In order to investigate female lineages present in western Venezuela, RFLP haplogroups from mtDNA were obtained from 193 individuals with grandparents from this region, 81 from the State of Lara (Barquisimeto) and 112 from 3 towns of the State of Falcon (Macuquita=25; Macanilla=29 and Churuguara=58). Comparison of haplogroup distributions between groups was performed, and admixture estimates based on female lineages were obtained. The distribution of four Amerindian haplogroups was compared with those of other populations from the American Continent. In our four samples Amerindian haplogroups predominate, followed by those of African origin. In the comparison of the mtDNA Amerindian fraction with other populations we find that Macanillas, Lara and Churuguara are similar to South American and Amazonian groups whilst Macuquita is similar to groups from Aruba. Our findings suggest an important genetic diversity in this region, explained by migration routes to and from the south and the Caribean. They also suggest genetic relationship between prehispanic groups from Aruba and those from the Paraguaná peninsula, which have been inferred by archeological evidences. An increase in sample size and analysis of sequences for more precision is recommended. Key words: Mitocondrial DNA, haplogroups, Venezuelan population, Amerindians

Patterns of Spatial Variation of Assemblages Associated with Intertidal Rocky Shores: A Global Perspective

Assemblages associated with intertidal rocky shores were examined for large scale distribution patterns with specific emphasis on identifying latitudinal trends of species richness and taxonomic distinctiveness. Seventy-two sites distributed around the globe were evaluated following the standardized sampling protocol of the Census of Marine Life NaGISA project (www.nagisa.coml.org). There were no clear patterns of standardized estimators of species richness along latitudinal gradients or among Large Marine Ecosystems (LMEs); however, a strong latitudinal gradient in taxonomic composition (i.e., proportion of different taxonomic groups in a given sample) was observed. Environmental variables related to natural influences were strongly related to the distribution patterns of the assemblages on the LME scale, particularly photoperiod, sea surface temperature (SST) and rainfall. In contrast, no environmental variables directly associated with human influences (with the exception of the inorganic pollution index) were related to assemblage patterns among LMEs. Correlations of the natural assemblages with either latitudinal gradients or environmental variables were equally strong suggesting that neither neutral models nor models based solely on environmental variables sufficiently explain spatial variation of these assemblages at a global scale. Despite the data shortcomings in this study (e.g., unbalanced sample distribution), we show the importance of generating biological global databases for the use in large-scale diversity comparisons of rocky intertidal assemblages to stimulate continued sampling and analyses

Comparison of three quick methods to estimate crab size in the land crabs Cardisoma guanhumi Latreille, 1825 and Ucides cordatus (Crustacea: Brachyura: Gecarcinidae and Ucididae)

Quick, reliable and non destructive methods are necessary to estimate size structure on commercial land crabs, in order to acquire relevant information concerning the health of their populations. Cardisoma guanhumi and Ucides cordatus are two land crabs that are exploited at a high scale and also in an artisan way in the Caribbean area and in the coasts of Brazil, which populations are endangered due to uncontrolled exploitation. The purpose of this work is to provide various methods to estimate indirectly crab body size. Sampling was carried out in Carenero (C. guanhumi) and Cumaná (U. cordatus) (Venezuela). For each species, three methods were used to measure burrow diameter (Vernier, internal spring caliper and photograph), and these were correlated with real body size of the crabs. Model II linear regression analyzes, i.e. Ordinary Least Squares and Mayor Axis, were used to build and test the performance of forecasting models. Cardisoma guanhumi showed a high bivariate data dispersion using Vernier and photo measuring methods, increasing these towards larger animals. Less dispersion was achieved with the spring caliper method; this resulted in the most accurate measurements of indirectly estimated body size in C. guanhumi (r²= 0.61), whereas Vernier measurements were the least precise. On the other hand, all three methods gave reliable estimates for U. cordatus, being the Vernier method the most accurate (r²= 0.71). However, in both species, all forecasting equations overestimated the size of smaller crabs (those below the mean) but underestimated the size of larger crabs. Nevertheless, all three methods were statistically significant for each of the species, and looking at the above mentioned underand overestimations, they can serve as reliable and fast non-destructive tools to be used by resource managers and field biologists to acquire size structure information concerning these two species. Vernier and internal spring caliper methods are recommended for relative small sampling areas, while photo method is suggested to be used in very extensive sampling regionsPara la estimación de la estructura de tamaños en cangrejos terrestres comerciales y la obtención de información relevante para su manejo, es necesario utilizar métodos rápidos, confiables y no destructivos. Cardisoma guanhumi y Ucides cordatus son dos cangrejos terrestres que son explotados comercialmente en el Caribe y en Brasil. El propósito de este trabajo es suministrar métodos indirectos para la estimación del tamaño del caparazón de los cangrejos y por consiguiente, de la estructura de tallas. Los muestreos se llevaron a cabo en Carenero (C. guanhumi) y en Cumaná (U. cordatus) (Venezuela). Se utilizaron tres métodos para estimar el diámetro de sus madrigueras: Vernier, compás y fotografía. Estos se correlacionaron con el tamaño real del cangrejo. Se aplicó el análisis de regresión Ordinary Least Squares Model II y la capacidad de predicción se probó utilizando el modelo II Mayor Axis para las regresiones. Cardisoma guanhumi mostró una fuerte dispersión de sus datos en los métodos de Vernier y fotografía. Menos dispersión se obtuvo con el método del compás y fue el más preciso (r²= 0.61). Para U. cordatus las medidas con Vernier fueron la más adecuadas (r²= 0.71). Sin embargo los tres métodos fueron confiables. Los diferentes métodos mostraron ventajas y desventajas y dependerá del que aplique los métodos, decidir cuál será el más adecuado para sus propósito

Relación entre la abundancia de tres especies de playeros del género \u3cem\u3eCalidris\u3c/em\u3e Merren 1804 (Aves: Scolopacidae) y sus recursos alimenticios en la Laguna de Punta de Mangle, Isla de Margarita, Venezuela / Relationship Between the Abundance of Three \u3cem\u3eCalidris\u3c/em\u3e Sandpipers (Aves: Scolopacidae) and Their Food Resources in Punta de Mangle Lagoon, Margarita Island, Venezuela

Los humedales costeros son áreas importantes para las aves playeras migratorias, especialmente durante el período no reproductivo, ya que permiten suplir las demandas energéticas asociadas a la migración. La laguna de Punta de Mangle, en la isla de Margarita, es utilizada por Calidris pusilla, C. mauri y C. minutilla durante la migración post-reproductiva (septiembre-diciembre); sin embargo, se conoce poco acerca de su dieta, oferta de presas y condiciones abióticas que enfren-tan en este período. Este trabajo se enfocó en describir algunas condiciones abióticas y la dieta de las aves; además de esti-mar la riqueza y abundancia de presas y examinar su relación con los calidrinos pequeños. La recolección de datos se realizó quincenalmente (septiembre-diciembre 2016), en un transecto de 650 m en la planicie intermareal más utilizada por las aves. Las condiciones abióticas fueron descritas en términos de salinidad, amplitud intermareal, profundidad de la lámina de agua y granulometría y la abundancia de playeros se estimó mediante censos visuales. Para la descripción de la dieta, se analizaron muestras de heces, mientras que la riqueza y abundancia de presas se determinó analizando muestras de sedimento colecta-das para cada tamaño de presa (macrofauna y meiofauna) y la incidencia de biopelículas. Los resultados sugieren que Punta de Mangle es un sitio de parada importante en el Caribe, recibiendo un máximo de 548 individuos durante el pico de migración post-reproductiva, en noviembre. En el periodo de estudio, se observaron mejoras en la calidad del hábitat con el progreso de la migración y una abundancia y riqueza de recursos elevada, aunque variable espaciotemporalmente. Los recursos más frecuentemente consumidos por los Calidris fueron biopelículas, ostrácodos, copépodos, anfípodos, poliquetos y dípteros, y la dieta se ajustó a su disponibilidad, a pesar de la ausencia de relaciones estadísticamente significativas entre aves y recursos. Sin embargo, las sincronías fenológicas entre la abundancia de aves y algunas presas sugieren la existencia de relaciones que podrían no haberse detectado debido al efecto denso-dependiente de la depredación ejercida por las aves durante el pico migratorio. Esta investigación representa una aproximación integral a la ecología de parada de estas especies en el Caribe. Coastal wetlands are important areas for migratory shorebirds, especially during the non-breeding season, serving as fueling areas where birds get to meet the energy demands associated with migration. Punta de Mangle lagoon, in Margarita island, is used by Calidris pusilla, C. mauri and C. minutilla during fall migration (September-December); however, little is known about their diet, prey availability, or the abiotic condi-tions they face in this period. This work focused on describing some abiotic conditions and the diet of the birds; in addition to estimate prey richness, abundance and their relationship with small calidrine sandpipers abundance. Data collection was carried out biweekly (September-December 2016), in a 650 m transect on the intertidal mudflat most heavily used by birds. Abiotic conditions were described in terms of salinity, exposed intertidal amplitude, water depth and granulometry. Shorebird abundance was assessed by direct counts of flocks. Dropping samples were analyzed for diet description while prey richness and abundance was determined from core samples collected for each prey size (macrofauna and meiofauna) along with bio-film incidence data. Our results suggest Punta de Mangle is an important stopover site in the Caribbean, receiving a maximum of 548 individuals during the fall migration peak, in November. Over the analyzed period, an enhancement in habitat condition with the progress of migration was evident, and resource abundance and richness were high but variable at spatial and temporal scales. The resources more frequently consumed by birds were biofilms, ostracods, copepods, amphipods, polychaetes and dipteran. Overall, shorebird diet greatly matched resource availability despite the absence of statistically significant relationships between shorebird and feeding resources. However, the phenological synchronies between the abundance of birds and some prey suggest the existence of relationships that could not have been detected probably due to a denso-dependent effect of predation exerted by birds on prey stocks during migration peak. This research represents a comprehensive approach to the staging ecology of these species in the Caribbean

DIVERSIDAD MITOCONDRIAL EN EL NOR-OCCIDENTE DE VENEZUELA. IMPLICACIONES PARA PROBABLES RUTAS MIGRATORIAS PREHISPÁNICAS

RESUMEN La utilidad del ADN mitocondrial (ADNmt) para determinar afinidad genética entre grupos indígenas contemporáneos e inferir sobre migraciones, ha sido demostrada; pero la imposibilidad de estudiar grupos prehispánicos extintos, limita las inferencias sobre migraciones en esa época. El mestizaje en poblaciones neoamericanas ha sido caracterizado por uniones entre hombres europeos y mujeres indígenas, permitiendo detectar en la población contemporánea haplogrupos mitocondriales amerindios que informan sobre poblaciones extintas. Para conocer los linajes femeninos en el occidente de Venezuela, se estudiaron los haplogrupos del ADNmt a partir de RFLP, en una muestra de 193 individuos con antepasados procedentes del occidente de Venezuela, 81 del Estado Lara (Barquisimeto) y 112 de tres pueblos del Estado Falcón (Macu-quita=25, Macanillas=29 y Churuguara=58). Se comparó la distribución de haplogrupos entre las poblaciones y se estimó el mestizaje por línea femenina en ellas. Se comparó la distribución de cuatro haplogrupos indígenas con otras regiones de América. Se observa que en las cuatro poblaciones predominan haplogrupos amerindios, seguidos de los africanos. Al comparar la fracción indígena con el resto de América encontramos que Macanillas, Lara y Churuguara se asemejan a grupos de Amazonas y Suramérica, mientras que Macuquita a Aruba. Esto sugiere una diversidad genética importante en esa zona como probable ruta de paso hacia el sur y el Caribe; además refleja vínculos genéticos importantes entre grupos prehispánicos de Aruba y los de la Península de Paraguaná. Evidencias arqueológicas soportan estos postulados. Se recomienda aumentar la muestra y realizar análisis de secuencias para un nivel mayor de precisión. Palabras clave: ADN mitocondrial, haplogrupos, población venezolana, grupos indígenas. ABSTRACT Mitocondrial DNA (mtDNA) has been widely used to study genetic relationships between contemporary Amerindian groups and to infer ancestral migration movements; however inferences about migration routes of prehispanic extinct groups are difficult. Admixture of Neoamerican groups has been characterized by unions between European males and Amerindian females. This allows the identification in present populations of Amerindian mitocondrial haplogroups which give information on ancestral groups. In order to investigate female lineages present in western Venezuela, RFLP haplogroups from mtDNA were obtained from 193 individuals with grandparents from this region, 81 from the State of Lara (Barquisimeto) and 112 from 3 towns of the State of Falcon (Macuquita=25; Macanilla=29 and Churuguara=58). Comparison of haplogroup distributions between groups was performed, and admixture estimates based on female lineages were obtained. The distribution of four Amerindian haplogroups was compared with those of other populations from the American Continent. In our four samples Amerindian haplogroups predominate, followed by those of African origin. In the comparison of the mtDNA Amerindian fraction with other populations we find that Macanillas, Lara and Churuguara are similar to South American and Amazonian groups whilst Macuquita is similar to groups from Aruba. Our findings suggest an important genetic diversity in this region, explained by migration routes to and from the south and the Caribean. They also suggest genetic relationship between prehispanic groups from Aruba and those from the Paraguaná peninsula, which have been inferred by archeological evidences. An increase in sample size and analysis of sequences for more precision is recommended. Key words: Mitocondrial DNA, haplogroups, Venezuelan population, Amerindians

SSP: an R package to estimate sampling effort in studies of ecological communities

SSP (simulation‐based sampling protocol) is an R package that uses simulations of ecological data and dissimilarity‐based multivariate standard error (MultSE) as an estimator of precision to evaluate the adequacy of different sampling efforts for studies that will test hypothesis using permutational multivariate analysis of variance. The procedure consists in simulating several extensive data matrixes that mimic some of the relevant ecological features of the community of interest using a pilot data set. For each simulated data, several sampling efforts are repeatedly executed and MultSE calculated. The mean value, 0.025 and 0.975 quantiles of MultSE for each sampling effort across all simulated data are then estimated and standardized regarding the lowest sampling effort. The optimal sampling effort is identified as that in which the increase in sampling effort does not improve the highest MultSE beyond a threshold value (e.g. 2.5%). The performance of SSP was validated using real data. In all three cases, the simulated data mimicked the real data and allowed to evaluate the relationship MultSE – n beyond the sampling size of the pilot studies. SSP can be used to estimate sample size in a wide variety of situations, ranging from simple (e.g. single site) to more complex (e.g. several sites for different habitats) experimental designs. The latter constitutes an important advantage in the context of multi‐scale studies in ecology. An online version of SSP is available for users without an R background