Ecological importance of passive deposition of organic matter into burrows of the SW Atlantic crab Chasmagnathus granulatus
MetadataShow full item record
The burrowing crab Chasmagnathus granulatus is the most abundant bioturbator in estuarine intertidal sediments from southern Brazil to central Argentina. This crab is a deposit feeder that excavates and maintains large semi-permanent open burrows with funnel shaped entrances. In this study we showed that the funnel shaped burrows with low aspect ratio are the most common and, with field experiments, we demonstrated that these burrows are also the most efficient in the capture of organic matter. As shown by C isotopic signatures, the origin of trapped detrital material is Spartina densiflora. Burrows are distributed in the upper part of estuaries and saltmarshes, mostly in areas of low energy, and cover extensive areas between the marsh vegetation and the open estuary. Through sampling of crab densities and use of satellite images, we estimated the number of burrows of different shapes in the Bahia Blanca estuary (38°50’S), one of the largest estuarine intertidals in the SW Atlantic. After combining this information with the trapping efficiency of burrows of different shapes, we estimated that within 100 d, a crab bed could capture the entire annual production from a marsh area of similar size. Therefore, we suggest that these extensive burrow beds may be considered large macrodetritus retention areas, reducing the amount of organic matter exported from marshes but locally increasing the sediment organic matter content.
Author Posting. © Inter-Research, 2006. This article is posted here by permission of Inter-Research for personal use, not for redistribution. The definitive version was published in Marine Ecology Progress Series 312 (2006): 201-21, doi:10.3354/meps312201.
Showing items related by title, author, creator and subject.
Gervais, Jennifer A.; Hunter, Christine M.; Anthony, Robert G. (2005-07-21)We used population models to explore the effects of the organochlorine contaminant p,p'DDE and fluctuations in vole availability on the population dynamics of Burrowing Owls (Athene cunicularia). Previous work indicated ...
Impact of burrowing crabs on C and N sources, control, and transformations in sediments andfood webs of SW Atlantic estuaries Botto, Florencia; Valiela, Ivan; Iribarne, Oscar; Martinetto, Paulina; Alberti, Juan (Inter-Research, 2005-06-02)The intertidal burrowing crab Chasmagnathus granulatus is the dominant species in soft bare sediments and vegetated intertidal areas along the SW Atlantic estuaries (southern Brazil, 28°S, to northern Patagonia, 42°S). C. ...