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Effect of burrowing by the crab helice crassa on chemistry of intertidal muddy sedimentsa
Author(s) -
Williamson R. Bruce,
Wilcock Robert J.,
Wise Bridget E.,
Pickmere Stuart E.
Publication year - 1999
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620180928
Subject(s) - bioturbation , anoxic waters , sediment , burrow , environmental chemistry , intertidal zone , sulfide , hydrous ferric oxides , chemistry , total organic carbon , ferric , geology , geochemistry , oceanography , inorganic chemistry , organic chemistry , sorption , geomorphology , paleontology , adsorption
The chemical environment was measured in vertical and horizontal profiles of cores taken from intertidal sediments that are extensively burrowed by the mud crab Helice crassa . The crab burrows folded the thin (2–5 mm) oxic layer into the sediment, and the burrows appeared to have a strong influence on the concentrations of acid volatile sulfide (AVS), acid‐extractable Fe II (probably FeCO 3 and FeS), Fe III (probably predominantly hydrous ferric oxide FeOOH), and Mn II, III, IV and a modest effect on FeS 2 but no effect on total organic carbon, total organic nitrogen, or acid‐extractable zinc concentrations. The oxic layer was thinner in the burrows than on the sediment surface and showed some minor differences in solid‐state chemistry, with higher FeOOH and lower FeS 2 concentrations in the burrow walls. Acid volatile sulfide, FeCO 3 , and FeS 2 were found in the oxic layers, presumably because of deposits from crab excavations of deeper anoxic sediments. The chemistry of the bioturbated profile was highly variable, not only because of existing burrows but also because of infilled abandoned burrows. The colors of the sediment profile were strongly related to the concentrations of Fe II , AVS, Fe III , Mn, and FeS 2 . The implications of the observed sediment chemistry to the fate and bioavailability of contaminants is discussed.