Sea Cucumber as Bioindicator of Trace Metal Pollution in Coastal Sediments.

Sea cucumbers are fished worldwide for export to Asia, but few studies have evaluated metal pollution and risk assessment. This study assessed concentration of trace metals and the potential ecological risk in sea cucumber (Holothuria floridana) and sediments at the Cispatá Bay, in the Caribbean Coast of Colombia. The trace metal concentrations in biota and sediments showed a similar decreasing trend as follows: Cu > Zn > Hg > Pb > Cd. The highest bioconcentration factor was found for Hg, and according to the sediment quality guidelines, Cu levels indicate adverse biological effects in the ecosystem. In this regard, Cu levels were higher than effects range low and the threshold effect levels (TEL) and lowest effect level in all the stations, whereas Hg levels were higher than TEL in most of them. Results for health risk assessment based on the maximum allowable daily consumption rate (CRlim) suggest that there is no risk to adults; however, children should limit or avoid its consumption. Results from multivariate statistical analysis suggest that agricultural activities (i.e., application of fertilizers and agrochemicals) were identified as the main anthropogenic sources of metal pollution. This research suggest that sea cucumber could be used as a bioindicator species in studies of monitoring metal contamination, with special attention to the highly significant correlation between Zn in tissue and sediments. This study also reveals that anthropic activities may have negative effects in the quality of the sediments of the bay and contributing to the knowledge of metal accumulation in sea cucumber.Graphical abstract.

Densidad poblacional y estructura de talla del pepino de mar Holothuria (Halodeima) grisea (Aspidochirotida: Holothuriidae) en aguas someras del sur del golfo de Morrosquillo, Caribe Colombiano / Density population and size structure of the sea cucumber Holothuria (Halodeima) grisea (Aspidochirotida: Holothuriidae) in shallow waters south of the gulf of Morrosquillo, Colombian Caribbean

Resumen Holothuria grisea, a pesar de no ser considerado un recurso comercial, ha sido objeto de extracciones ilegales en Colombia, hecho que se vuelve más grave debido al vació de información biológica de estos organismos. Por esta razón, se estimó la densidad poblacional y estructura de talla de H. grisea en tres sectores del sur del golfo de Morrosquillo de abril a noviembre 2015. Para ello, se ubicaron mensualmente tres transectos circulares en cada sector de muestreo abarcando un área de 300 m2, donde se contabilizaron y midieron in situ los individuos encontrados. La densidad media de H. grisea en el área estudiada fue 0.4 ind m-2, presentándose los mayores valores en el sector La Ahumadera (1.09 ± 0.11 ind m-2) y los menores valores en el Banco de Arena (0.02 ± 0.004 ind m-2). El análisis de varianza señalo una diferencia significativa en los valores de densidad y talla de H. grisea en los sectores estudiados. La especie presentó una distribución de tallas unimodal, registrándose una talla promedio de 13.5 ± 0.91 cm con una talla mínima de 2.5 y una máxima de 30 cm, en general las tallas intermedias presentaron una mayor representatividad a lo largo de este estudio (77.2 %). Los aspectos biológicos presentados en este documento son de gran importancia para la conservación de esta especie y corresponde a un avance en el conocimiento de la clase Holothuroidea en el Caribe Colombiano.

Abstract Holothuria grisea, despite not being considered a commercial resource has been the subject of illegal extractions in Colombia, a fact that becomes more serious due to the empty of biological information of these organisms. For this reason the density population and size structure of H. grisea were evaluated in three sectors south of the gulf of Morrosquillo from April to November 2015. To this end, three circular transects were located each month in each sampling site covering an area of 300 m2, where individuals were counted and measured in situ. The average density of H. grisea in the study area was 0.4 ind m-2, with the highest values in the La Ahumadera (1.09 ± 0.11 ind m-2) and the lowest values in Banco de Arena (0.02 ± 0.004 ind m-2). The analysis of variance showed a significance in the values of density and size of H. grisea in the studied sectors. The species presented a unimodal distribution of sizes with an average size of 13.5 ± 0.9 cm with a minimum size of 2.5 and a maximum of 30 cm, intermediate sizes generally showed a higher representativeness throughout this study (77.2 %). The biological aspects presented in this paper are of great importance for the conservation of this species and corresponds to an advance in the knowledge of the Holothuroidea class in the Colombian Caribbean. Rev. Biol. Trop. 66(2): 776-787. Epub 2018 June 01.

Polycyclic aromatic hydrocarbons and heavy metals in the Cispata Bay, Colombia: A marine tropical ecosystem.

The concentrations of polycyclic aromatic hydrocarbons and heavy metals were evaluated in shallow sediments, water, fish and seabird samples from the Cispata Bay, Colombia. The heavy metals concentrations in the sediment was in the following order: Cu>Pb>Hg>Cd. The heavy metal concentration was different (p<0.05) in juvenile and adult birds. High concentrations of mercury were registered in the seabird (10.19±4.99mgkg-1) and fish (0.67µgg-1) samples. The total concentration of polycyclic aromatic hydrocarbons ranged from 7.0-41ngg-1 in sediment, 0.03-0.34ngmL-1 in water samples, 53.24ngg-1 in fish, and 66ngg-1 in seabirds. The high concentrations of heavy metals in seabirds may be explained by their feeding habits. The presence of polycyclic aromatic hydrocarbons in the Cispata Bay may be due to hydrocarbon spills during oil transport at the nearby oil port.

Equinodermos enffondos someros del sector la ahmadera, bahía de cispatá, córdooba, caribe Colombiano / Echinoderms in Shallow-Bottom from Ahumadera Sector, Cispatá Bay, Cordoba, Colombian Caribbean

Este estudio representa un reporte de la fauna de equinodermos que se encuentran en fondos someros del sector La Ahumadera, bahía de Cispatá, Caribe colombiano. El área está formada por un sustrato de tipo fango-arenoso colonizado por esponjas en punta Terraplén, y arenoso con pasto marino (Thalassia testudinum), macroalgas y esponjas en punta Robalo. Se identificaron diez especies de equinodermos que pertenecen a cuatro clases (Asteroidea, Ophiuroidea, Echinoidea y Holothuroidea), distribuidas en ocho familias y nueve géneros. El número de taxones identificados corresponde al 4,1% de las especies registradas para el Caribe colombiano, y muestra la representatividad de especies de equinodermos en este sector. Las especies más abundantes en punta Robalo fueron Encope michelini (24,3%) y Ophiothrix angulata, mientras que en punta Terraplén fueron los ofiuros O. angulata (36,7%) y Ophiactis savignyi (16,5%). Se determinó mayor riqueza (S= 9), diversidad (H'= 2,64) y uniformidad (U= 0,92) de especies en punta Robalo al ser comparado con los valores obtenidos en Terraplén (S= 6, H'= 2,39 y U= 0,83). Ambas estaciones mostraron un índice de similitud (Is) de 0,66. Entre las especies identificadas, las siguientes son nuevos registros para el departamento de Córdoba: Holothuria floridana, Encope michelini y Mellita quinquiesperforata.

This study represents a report of the echinoderm fauna found in shallow waters of the sector La Ahumadera, Cispatá Bay, Colombian Caribbean. The area is formed by a plain substrate type soft sand-mud colonized by sponges in punta Terraplén and sandy with seagrass (Thalassia testudinum), macroalgae and sponges in punta Robalo. Were identified ten species of echinoderms belonging to four classes (Asteroidea, Ophiuroidea, Echinoidea and Holothuroidea), distributed in eight families and nine genera. The number of taxa identified corresponds to 4.1% of the species recorded for the Colombian Caribbean, and shows the representation of species of echinoderms in this sector. The most abundant species in punta Robalo were Encope michelini (24.3%) and Ophiothrix angulata, while in punta Terraplén were O. angulata (36.7%) and Ophiactis savignyi (16.5%). Higher richness (S= 9), diversity (H'= 2.64) and evenness (U= 0.92) were found in punta Robalo compared to values from Terraplén (S= 6, H'= 2.39 and U= 0.83). Both stations showed a similarity index (Is) of 0.66.Among the species identified, the following are new records for the department of Córdoba: Holothuria floridana, Encope michelini and Mellita quinquiesperforata.

Dinámica del manglar en el complejo lagunar de Cispatá (Caribe colombiano) en los últimos 900 años

Mangrove dynamics in the Cispata lagoon system (Colombian Caribbean) during last 900 years. The lagoon complex of Cispatá (old Sinú river delta) located at the Northwestern coast of the Colombian Caribbean, encloses one of the biggest mangrove areas in this region. This area has changed during the last 330 years because of several environmental and climatic causes, mainly changes in the position of the delta (Sinú River), which is the main freshwater source in this area, and sea level rise. We hypothesized that the climatic and geomorphologic dynamics has caused changes in the extension and composition of mangrove vegetation, especially during last 150 years. The dynamics of mangroves during the last 900 years was reconstructed based on the changes in the stratigraphy, pollen record, calcite concentrations (CaCO3) and C/N ratio, along two sediment cores from La Flotante and Navio lagoons, located in Cispatá complex. The age model was built based on lineal interpolation of 210Pb ages and changes in granulometry. Establishment and expansion of mangrove forests during the last 900 years were related to fluviomarine dynamics in the area and the lagoon formation. During the period encompassed between 1064 and 1762 A.D., the Mestizos spit was formed when marine conditions predominated in the surroundings of La Flotante Lagoon. At the site of Navío, a river dominated lagoon, terrigenous conditions dominated since 1830. Although the colonization of herbaceous pioneer vegetation started between 1142 and 1331 A.D., mangrove colonization only took place since 1717 A.D. Mangrove colonization was a result of the delta progradation. In 1849 A.D. the Sinú river delta migrated to the Cispatá bay. The eustatic sea level rise, the increase in river discharges and sedimentation rates produced the establishment of mangrove forests dominated by Rhizophora since 1849. Since 1900 a marine intrusion was recorded in both lagoons. In 1938, the migration of the delta toward its actual location in Tinajones gave place to the formation of the present lagoon system and to the expansion of mangrove forests, which reflects the balance between the high alluvial sediment input and the current sea level rise as has been recorded in similar ecosystems. Rev. Biol. Trop. 58 (4): 1347-1366. Epub 2010 December 01.

En el complejo lagunar de Cispatá se localiza una de las mayores extensiones de manglares del Caribe colombiano. Por medio del análisis de los cambios en la estratigrafía, el registro palinológico, la concentración de calcita y la relación carbono-nitrógeno, en dos secciones de sedimentos, se reconstruyó la dinámica de estos manglares durante los últimos 900 años. Las edades se establecieron con base en dataciones con 210Pb y análisis granulométrico. El establecimiento y expansión de los manglares, se relacionó con los procesos fluviomarinos que involucraron la formación de las lagunas. Entre 1064 A.D. y 1762 A.D. se formó la espiga Mestizos y predominaron condiciones marinas. La colonización de la vegetación herbácea ocurrió entre 1142 y 1331 A.D. y la de los manglares a partir de 1717 A.D., por la progradación del delta. Desde 1849 A.D., la migración del delta hacia la bahía de Cispatá, el incremento en el nivel del mar y las tasas de acreción de sedimentos aluviales, permitieron la expansión del manglar en el área. A partir de 1900 se registró una intrusión marina en ambas lagunas. A partir de 1938 A.D, la migración del delta a su posición actual dio origen al sistema lagunar y mayor expansión de los manglares.