INVESTIGADORES
PERILLO Gerardo Miguel E.
artículos
Título:
Novel mechanism of stream formation in coastal wetlands by crabfishgroundwater interaction.
Autor/es:
PERILLO, G.M.E.,; MINKOFF, D.R.; PICCOLO, M.C.
Revista:
GEO-MARINE LETTERS
Editorial:
Springer Verlag
Referencias:
Lugar: Berlin; Año: 2005 vol. 25 p. 214 - 220
ISSN:
0276-0460
Resumen:
A novel mechanism of stream development in coastal wetlands was observed in the form of interaction between the burrowing crab (Chasmagnathus granulata) and groundwater seepage. This process may eventually be further promoted by the predatory action of the white croaker fish (Micropogon opercularis). These so-called crab streams occur on the banks of major tidal channels in a salt marsh of the Bahı´ a Blanca Estuary (Argentina). As the tide recedes, wateris retained in the crab burrows on the marsh surface. The presence of lateral burrows produced by crab recruits promotes subterranean piping flow driven by the hydraulic head in the vertical burrow. Groundwater generally seeps along the tidal channel banks but is particularly prominent and concentrated where crab burrows perforate the banks. Where predatory attacks by the croaker fish enlarge the burrow mouths, the drainage rills become wider and deeper because more seeping water is collected in the shallow crater from where it is funnelled into the developing streams. The crab stream is then produced by water draining from the crab burrow mouth, acting initially by cutback erosion and followed by forward erosion of the relatively unconsolidated muddy sediments.