A Needle in a Haystack: Landscape Survey and Archaeological Detection Experiments in Apalachee Bay

This paper presents the results of a pilot landscape‐scale seismic survey undertaken in Apalachee Bay, Florida, across a submerged landscape that contains dozens of Pre‐Contact sites. In addition to the goals of improving the geophysical and remote sensing ground model for this submerged landscape, the survey also sought to undertake the first independent scientific test of the contentious ‘HALD’ methodology, an acoustic resonance method that it is claimed to identify knapped lithic artefacts at and/or below the seabed through the identification of distinct ‘haystack’ responses. The results of this work indicate that the HALD method, as currently described, produces results that could not be scientifically replicated in this survey. We conclude that any HALD ‘haystack’ signal should therefore not be considered as an example of detection of human‐modified lithic material but rather as a geophysical anomaly that requires additional constraints before it can be used to reliably identify human‐modified lithic materials. Thus, although the authors note that laboratory studies have successfully produced an acoustic signal in human‐modified lithics, the field‐based methods remain yet to be reliably determined. In addition to these results, the landscape mapping survey also recorded valuable information on buried and previously unrecorded landscape features that have archaeological significance and that may guide future site prospection. We therefore conclude that despite the results of the HALD test, the well‐preserved submerged landscape of Apalachee Bay region provides a highly useful testing ground for methods that can be deployed elsewhere globally.