Microplastics and plastisphere at surface waters in the Southwestern Caribbean sea.

Pollution generated by plastic waste has brought an environmental problem characterized by the omnipresence of smaller pieces of this material known as microplastics (MP). This issue was addresses by collecting samples with 250 µm pore size nets in two marine-coastal sectors of Southwestern Caribbean Sea during two contrasting seasons. Higher concentrations were found in rainy season than in dry season, reaching respectively 1.72 MP/m3 and 0.22 MP/m3. Within each sector, there were differences caused firstly by localities of higher concentrations of semi-closed water bodies localities during rainy season (Ciénaga Grande de Santa Marta and La Caimanera marsh), and secondly by lower concentrations of localities with less influenced of flow rates during dry season (Salamanca and Isla Fuerte). Moreover, the lowest concentration in dry season corresponding to La Caimanera marsh reflects how the community environmental management might decrease MP pollution. In both sectors and seasons, the particles of 0.3 mm (0.3-1.4 mm) size class dominated over those of 1.4 mm (1.4-5.0 mm) (reaching each respectively 1.33 MP/m3 and 0.39 MP/m3), with a dominance of fibers, except in the rainy season in Magdalena, where they were films. Using the FTIR technique, polypropylene was identified as the most abundant polymer in both sectors. The composition of the assemblage of microorganisms attached to microplastics presented higher richness and differed from that of free-living planktonic microbes. The most abundant members of the plastisphere were proteobacteria whose major representation was the pathogenic genus Vibrio, while the cyanobacteria dominated in seawater samples.

Predator control of marine communities increases with temperature across 115 degrees of latitude.

Early naturalists suggested that predation intensity increases toward the tropics, affecting fundamental ecological and evolutionary processes by latitude, but empirical support is still limited. Several studies have measured consumption rates across latitude at large scales, with variable results. Moreover, how predation affects prey community composition at such geographic scales remains unknown. Using standardized experiments that spanned 115° of latitude, at 36 nearshore sites along both coasts of the Americas, we found that marine predators have both higher consumption rates and consistently stronger impacts on biomass and species composition of marine invertebrate communities in warmer tropical waters, likely owing to fish predators. Our results provide robust support for a temperature-dependent gradient in interaction strength and have potential implications for how marine ecosystems will respond to ocean warming.

La relación entre peltigera sp. y rhizophora magle en arroyo de plata (Bolívar), caribe Colombiano / The relationhip between peltigera sp. and rhizophora manglein arroyo de pllata (bolivar), Colombian caribbean region

Objetivo: determinar la distribución y el estado de los rodales de manglar en Arroyo de Plata (Departamento de Bolívar). Metodología: se realizaron labores de campo a través del arbolado, mediante el muestreo biológico de la flora y de los parámetros físicos y químicos del agua y de los suelos a lo largo de transectos dentro del bosque. Resultados: la composición del rodal incluye cinco especies, Rhizophora mangle (mangle rojo, colorao o colorado), Avicennia germinans (mangle salado, prieto, negro o iguanero), Laguncularia racemosa (mangle blanco, amarillo o bobo), Conocarpus erecta (mangle zaragoza) y Pelliciera rhizophorae (mangle piñuelo). Asociado a la especie pionera (R. mangle) se encontró el líquen (Peltigera sp.), cuya relación se lleva a cabo solo cuando el mangle está en estado de degradación y los parámetros fisicoquímicos de las aguas y los suelos, son extremos. Conclusión: Los manglares mostraron características mixtas, tipo maduro ribereño y de cuenca, donde la especie invasora P. rhizophorae presenta el mayor IVI, debido a su alta densidad. El registro de los líquenes Peltigera sp. y su presencia en los manglares del Caribe colombiano no solo es el primero para esta Región, su distribución puede estar restringida a la zona costera, es incidental, y demuestra su gran capacidad de adaptación a los cambios ambientales, y puede ser considerada entre los en bio-indicadores de las características ambientales, especialmente de las alteraciones actuales de los suelos y las aguas.

Objective: To determine the distribution and status of mangrove stands in Arroyo de Plata (Department of Bolívar). Methodology: Field work was conducted through woodland, using biological sampling of the flora and the physical and chemical parameters of water and soil along transects within the forest. Results: The composition of the stand includes five species, Rhizophoramangle (red, colorao or colorado mangrove), Avicenniagerminans (salty, dark color, black or iguanero mangle) Laguncularia racemosa (white, yellow or bobo mangrove), Conocarpus erecta (zaragoza mangle) and Pelliciera rhizophorae (tea mangrove). The lichen (Peltigera sp), was found associated with the pioneer species (R. mangrove) whose relationship is carried out only when the mangrove is in a state of degradation and the physical-chemical parameters of water and soil, are extreme. Conclusion: Mangroves showed mature coastal basin type mixed characteristics, where the invasive species P. rhizophorae has the highest IVI due to its high density. Registration of Peltigera sp lichens and its presence of the Colombian Caribbean mangrove is not only the first for this region, its distribution may be restricted to the coastal zone, it is incidental and demonstrates its ability to adapt to environmental changes, and can be considered between the bio-indicators of environmental characteristics, especially of the the current alterations of soil and water.