Spatial and temporal variation in aquatic macroinvertebrates in the Okefenokee Swamp, Georgia, USA

Abstract

Aquatic macroinvertebrates of the Okefenokee Swamp have been largely overlooked despite their ecological importance and value as water quality indicators. In a two-year study we analyzed taxon richness and abundances of individual macroinvertebrate taxa in the Okefenokee Swamp to assess temporal variation among seasons and spatial variation among five plant community habitats (marsh prairies, cypress forest, scrub-shrub thickets, deepwater lakes, and boat trails) and across six areas of the Okefenokee. Chironomid and ceratopogonid midges and water mites numerically dominated the macroinvertebrate community, and chironomids, dytiscid beetles, and libellulid dragonflies had the greatest generic richness. Multivariate analysis of macroinvertebrate community structure did not show clear patterns among seasons, habitats, or areas. Furthermore, few individual taxa had either spatial or temporal variation in abundance. Wetland macroinvertebrate communities were relatively homogenous across the Okefenokee Swamp possibly because conditions important to these organisms did not vary dramatically among habitats or seasons. Alternatively, most resident taxa might be ecological generalists able to exploit a broad range of conditions.