Abstract
Habitat complexity and biodiversity are commonly linked concepts in ecological research. Within aquatic ecosystems, the physical structure and complexity of woody debris provides critical habitat for organismal survival. Marine wood-boring invertebrates accelerate the degradation of wood debris, creating burrows that potentially provide living space for diverse communities. Understanding the overall effects of wood boring engineers and the mechanisms that contribute to variation in their impacts are essential to predict how they alter community structure and dynamics over time. I performed a manipulative field experiment that examines how the engineering role of marine wood boring invertebrates influences the habitat structure of complex artificial substrate units and how the resulting bioeroding changes affect species richness, diversity, and composition of faunal species utilizing the habitats. Fourteen pairs of standardized wood and fiberglass artificial substrate units designed to replicate the natural branching complexity of wood debris were deployed in a randomized block design along the shallow subtidal zone at Rookery Bay National Estuarine Research Reserve in Naples, Florida and left in place for one year to allow for colonization by borers and other invertebrates, and to measure potential changes in habitat complexity. Structural changes from boring behavior and community composition were analyzed through paired T-tests, N-MDS, ANOSIM, and SIMPER. Overall, results indicated that boring attack by marine invertebrates significantly reduced the available length, surface area and volume in wood substrate units compared to fiberglass treatments. Such substantial loss of wood habitat resulted in a significant reduction in epibiont abundance, richness, and diversity compared to fiberglass treatments. The magnitude of observed substrate degradation in this study and the resulting community level consequences suggest that engineered biodegradation from wood boring invertebrates may indirectly influence the ability of fauna to seek protection from predation or tidal stress. While these findings begin to link the community-level consequences that result from wood boring bioerosive behavior, questions remain how scale-dependent factors may influence habitat alteration on community structure.