The use of conductivity probes to locate animal burrows in mangrove swamps

Subterranean burrows in mangrove swamps may be located in situ by use of an electronic probe. An array of ring electrodes mounted on a rod provides an effective means of measuring the apparent electrical conductivity in sediment. The variations in the conductivity indicate different sediment characteristics. In this work, the probe is used to locate voids in the sediment; i.e. burrows formed by animals. Upon location of the burrows, samples of the burrow water were extracted for testing. The concentrations of dissolved nitrogenous compounds and of salt were determined to investigate the tidal flushing of the burrows. The concentrations of nitrogen-based solutes compared favorably with previous studies and indicate little variation with depth. The salinity data support the hypothesis that significant mixing of burrow water occurs throughout the entire depth of the burrow.