Wood taphonomy in a tropical marine carbonate environment: Experimental results from Lee Stocking Island, Bahamas
Abstract Both teredinid bivales and limnorid isopods attacked wood that was deployed experimentally for two years in a carbonate environment. On average, wood samples collected after one year on the sea floor lost 17% of their original surface area to Limnoria and 50% of their original volume to teredinids. After two years on the sea floor, wood samples lost an average of 39% of their original surface and 74% of their original volume. All samples of kiln-dried lumber ( Pinus , Sequoia , Araucaria , Magnolia , and Quercus ) experienced significantly more attack by teredinids and Limnoria than samples of Quercus stellata (post oak) branch wood that experienced terrestrial decomposition in a warm-temperate environment for five years before deployment on the sea floor. Taphonomic loss rates for wood in marine environments based on kiln-dried lumber may overestimate loss rates for natural wood entering marine environments after initial decomposition in terrestrial environments. Burial appears to play an important role in wood taphonomy. Burial to a depth of > 3 cm inhibited destruction by Limnoria , but not teredinids, possibly due to the greater tolerance of molluscs for low O 2 levels and the ability of teredinids to raise their siphons above the wood surface. Both limnorids and teredinids may contribute to the formation of Teredolites (disaggregated, sediment-filled teredinid borings). Limnorid isopods remove the surface of wood exposing the calcite-lined borings of teredinids. Once their calcite-lined borings are exposed, teredinid are susceptible to predation, and in the aftermath of predation, teredinid borings may become sediment filled. Exposure also causes the calcite-lined borings to break and disaggregate, leading to the formation of Teredolites . The fossil record of teredinids reaches back to the Jurassic. Limnoria traces in the surface of wood are distinctive and diagnostic at the species level; however Limnoria have a sparse fossil record.