Predicting recovery of soft sediment communities following physical disturbance

This study investigated the effects of physical disturbance on intertidal benthic habitats and communities. The aim of the work was to examine the use of physical habitat characteristics as a surrogate for biological recovery as an aid to the management of shallow water marine habitats. The first field experiment investigated the effects of two intensities of a disturbance treatment on a sandflat habitat and community. Community recovery from the lower intensity treatment was complete after 63 days whereas recovery following from the higher intensity disturbance took at least twice as long. There were no effects of the disturbance detected for any of the measured sediment parameters. Depth of disturbed pits gradually decreased over time and was correlated to benthic community structure. A comparison of macrofaunal and meiofaunal recovery as part of the same experiment revealed that significant differences existed in disturbed meiofaunal communities 32 days following the disturbance event. A second field experiment investigated the recovery rates of benthic communities from a range of soft sediment habitats following the application of a uniform disturbance treatment. Communities from clean sand sediments were less negatively impacted and recovered more rapidly following disturbance than muddy sediment communities. No effects of the disturbance treatment were detected for any of the measured sediment parameters. However, the rate of infilling of the disturbed plots could be used to predict the recovery rate of the associated community. An in situ device for the measurement of sediment properties used in this study is described and it's potential for use in ecological studies is discussed. Measuring the rate of habitat restoration could be an rapid and amenable method for predicting the recovery of intertidal benthic communities from a range of anthropogenic activities that impact upon intertidal areas