INVESTIGADORES
PERILLO Gerardo Miguel E.
artículos
Título:
Novel mechanism of stream formation in coastal wetlands by crab¿fish¿groundwater interaction.
Autor/es:
PERILLO, GERARDO M. E.; MINKOFF, DARIO R; PICCOLO, M CINTIA
Revista:
GEO-MARINE LETTERS
Editorial:
Springer
Referencias:
Lugar: Heidelberg; Año: 2005 vol. 25 p. 124 - 220
ISSN:
0276-0460
Resumen:
A novel mechanism of stream development incoastal wetlands was observed in the form of interactionbetween the burrowing crab (Chasmagnathusgranulata) and groundwater seepage. This process mayeventually be further promoted by the predatory actionof the white croaker fish (Micropogon opercularis).These so-called crab streams occur on the banks ofmajor tidal channels in a salt marsh of the Bahı´aBlanca Estuary (Argentina). As the tide recedes, wateris retained in the crab burrows on the marsh surface.The presence of lateral burrows produced by crabrecruits promotes subterranean piping flow driven bythe hydraulic head in the vertical burrow. Groundwatergenerally seeps along the tidal channel banksbut is particularly prominent and concentrated wherecrab burrows perforate the banks. Where predatoryattacks by the croaker fish enlarge the burrow mouths,the drainage rills become wider and deeper becausemore seeping water is collected in the shallow craterfrom where it is funnelled into the developing streams.The crab stream is then produced by water drainingfrom the crab burrow mouth, acting initially by cutbackerosion and followed by forward erosion of therelatively unconsolidated muddy sediments.