Study of the bioerosion of Phoenician elephant tusks from the shipwreck of Bajo de la Campana: lots of hypotheses, few certainties

The shipwreck of Bajo de la Campana (VII–VI century B.C.) was a Phoenician merchant ship accidentally discovered in the 1950s off the coasts of the Murcia region (Spain). Sixty-four elephant tusks were part of the cargo. Some of them were recovered by archaeologists between 2007 and 2011 and are now stored in the restoration laboratory of the National Museum of Underwater Archaeology (ARQVA) of Cartagena. This study investigated the bioerosion traces present on 12 selected tusks in order to hypothesize which marine or terrestrial macroborers could have attacked this substrate. No work has previously looked at the biological degradation of this material. Taking into account the mineral composition of ivory, the hypothesized bioeroders were selected from those reported in the literature as bioeroders of rocks or other hard substrates (bones, corals, shells, etc.). The hypothesized biodeteriogens belongs to several groups of marine invertebrates (echinoids, barnacles, molluscs, sponges, polychaetes, and bryozoans) and terrestrial insects. Unfortunately, the absence of parts of the bioeroders’ body or of skeletal elements inside the studied traces did not allow definitive identification, so the attributions remain hypotheses. However, this study could be considered a starting point for an interesting debate and for future investigations on the bioerosion of this precious material.