INVESTIGADORES
PERILLO Gerardo Miguel E.
congresos y reuniones científicas
Título:
Effect of plant-bioturbation interaction on tidal creek growthin two contrasting saltmarsh habitats.
Autor/es:
ESCAPA, C.M.,; PERILLO, G.M.E.; IRIBARNE, O.O.,
Lugar:
Bahía Blanca
Reunión:
Congreso; ECSA 44: SCIENCE AND MANAGEMENT OF ESTUARIES AND COASTS: A TALE OF TWO HEMISPHERES; 2008
Institución organizadora:
Estuarine Coastal Science Association-Instituto Argentino de Oceanografía
Resumen:
There is strong evidence about the role of saltmarshes as protectors of the coastline, and a high proportion of the saltmarsh lossmay be due to bioturbation activity that destabilizes sediments. Using field measurements and experiments, we investigated theeffect of the Southwest Atlantic burrowing crab Neohelice granulata on the inland growth of tidal creeks in contrasting saltmarshhabitats (Bahía Blanca Estuary). This crab species inhabits both Sarcocornia perennis-dominated marshes and Spartina alternifloramarshes. Crab activity in relation with tidal creek growth, crab effect on sediments, plant biomass and architecture, and sedimentdeposition rates were evaluated in both types marshes. Bioturbation activity by this crab changed sediment physical parameters, aspenetrability, water content, and shear strength; which are related to sediment erodability in both marshes. There was a positiverelationship between crab activity and creek growth rates for Sarcocornia saltmarshes, and no significant relationship was foundbetween those variables in Spartina marshes. Field experiments show that bioturbation by N. granulata and their burrows enhancegrowth rates of tidal creeks, promoting marsh erosion on Sarcocornia marshes but crab presence did not affect growth rates ofcreeks in Spartinamarshes. When crabs were present, these creeks grew faster than creeks where crabs were excluded. Plant biomass was higherin Spartina marshes than Sarcocornia marshes during the year; consequently, sediment deposition rates were higher in Spartinamarshes than in Sarcocornia dominated marshes. The implication is that bioturbation effects on creek growth may producecontrasting outcomes depending on the habitat structure.
