Vol. 14 Núm. 2 (2007)
Cover Photo: Presence of biofilm on a tidal plain in Bahía Blanca Estuary. Some pieces of the organic layer had been torn off by erosion. The presence of bubbles is due to the cohesive microbial films that inhibit escape of the gas, which came from deeper buried organic deposits, into the air or water. When accumulating beneath the surface mat, gas pressure leads to doming the mat. Photo: Diana Cuadrado.