Alternate Title

Macroinvertebrate Colonization of the Intertidal Habitat of a Dredge Spoil Island in North Florida


Macroinvertebrate colonization of the intertidal habitat of a dredge spoil island was studied for one year by collecting triplicate 0.0625-m2 x 10-cm core samples of substratum from four stations established relative to the slope of the habitat. Fauna first colonized the subtidal site, and after lapses of time appeared respectively at low, mid and high-tide stations. The total abundance and diversity of the assemblage increased significantly in the latter half of the year mainly due to the appearance of late colonizers at low and mid-tide stations. The temporal abundance patterns at the four stations were variable. Several species that initially appeared at low tide station later aggregated at other stations. While no discrete species groups formed at each station, the relative abundances of several species were related to tidal exposure gradient. This phenomenon was reflected in the species dominance hierarchy at the four stations and spatial distributions in the intertidal zone. Equilibrium between extinction and immigration rates of species did not occur within the year. The intertidal assemblages as a whole did not show stability of species composition or species abundance.