1 3Geo-Marine LettersAn International Journal of MarineGeology ISSN 0276-0460Volume 32Number 4 Geo-Mar Lett (2012) 32:289-300DOI 10.1007/s00367-011-0268-5Selective geochemistry of iron in mangrovesoils in a semiarid tropical climate: effectsof the burrowing activity of the crabsUcides cordatus and Uca maracoaniJ.M.C.Arajo, X.L.Otero,A.G.B.Marques, G.N.Nbrega,J.R.F.Silva & T.O.Ferreira1 3Your article is protected by copyright andall rights are held exclusively by Springer-Verlag. This e-offprint is for personal use onlyand shall not be self-archived in electronicrepositories. If you wish to self-archive yourwork, please use the accepted authorsversion for posting to your own website oryour institutions repository. You may furtherdeposit the accepted authors version on afunders repository at a funders request,provided it is not made publicly available until12 months after publication.ORIGINALSelective geochemistry of iron in mangrove soils in a semiaridtropical climate: effects of the burrowing activity of the crabsUcides cordatus and Uca maracoaniJ. M. C. Arajo Jr. & X. L. Otero & A. G. B. Marques &G. N. Nbrega & J. R. F. Silva & T. O. FerreiraReceived: 19 May 2011 / Accepted: 21 November 2011 / Published online: 14 December 2011#Springer-Verlag 2011Abstract Bioturbation by crabs may affect processes asso-ciated with organic matter decomposition in mangrove soils.Thisstudyexamineshowtwocrabs(Ucamaracoani andUcidescordatus), whichareof substantial ecological andeconomicimportanceinsemiaridcoastal areas of Brazil,affect biogeochemical processes in mangrove soils. For thispurpose, thephysicochemicalandgeochemicalparametersof the soils at different sites were analyzed. The redoxpotential wasalwayspositiveat bioturbatedsites(+12to+218 mV), indicating more oxidizing conditions conducivetotheoxidationofpyriteandprecipitationofoxyhydrox-ides. In contrast,anoxic conditions prevailedat the controlsite(Eh