Fiddler crab (Uca spp.) burrows have little effect on surrounding sediment oxygen concentrations

Contrary to convictions in the literature, this study determined that, within poorly drained muddy sediments, oxygen penetration depth only had a significant increase out to a distance of 2 mm from the burrow wall, and the increase in oxygen depth penetration was only 0.5 mm compared to areas not affected by the presence of the burrow. In typical muddy sediments of salt marshes along the mid-Atlantic coast, USA, the presence of Uca pugnax burrows increased the oxic zone little, but may have had an effect on the extent of the suboxic zone. Therefore, generalizations should not be made concerning the ability of burrows to aerate surrounding bulk sediments. In addition, the capacity of sediments to drain is an important factor in determining the potential for increased sediment aeration due to the presence of Uca spp. burrows.