Biomonitoring of TBT contamination and imposex incidence along 4700 km of Argentinean shoreline (SW Atlantic: from 38S to 54S).

The imposex incidence and TBT pollution were investigated along 4,700km of Argentinean coast, including city harbors and proximal zones without marine traffic. We analyzed 1805 individuals from 12 gastropod species, including families Volutidae, Muricidae, Nassariidea, Calyptraidae, Marginellidae, and Buccinidae, and found the imposex phenomenon for the first time in six species. In high marine traffic zones, TBT pollution was registered and the percentage of imposex was high, while these occurrences were null in areas without boat traffic. The species that best reflect the degree of imposex were those inhabiting sandy/muddy or mixed bottoms. TBT determination and imposex incidence indicate that pollution was focused only in ports with high marine traffic or in areas where ship hulls are painted. This is the first report of an imposex-sediment approach to evaluate organotin contamination along the coast of a South American country.

Método alternativo para obtener y transportar bloques de tejido para microscopía / An alternative method to freeze and transport biological tissue blocks for microscopy

Se describe un método simple y económico para congelar material biológico destinado a la obtención de cortes histológicos en crióstato. Se propone la utilización de CO2 para producir una mezcla refrigerante en reemplazo del nitrógeno líquido como criogénico. Esta mezcla (compuesta por hielo seco y acetona) enfría el isopentano utilizado como medio de congelación hasta -76ºC y lo mantiene por ~1,5h permitiendo la congelación de más de 20 bloques de tejido. La calidad de las secciones obtenidas en crióstato es similar a aquellas obtenidas mediante la utilización de nitrógeno líquido. Este método resulta especialmente práctico durante los muestreos a bordo de embarcaciones y/o en sitios alejados de los centros urbanos.