The Promise and Peril of Coastal Infrastructure: Use Life of a Tidal Fish Trap on the Northern Gulf Coast of Florida, circa AD 400–650

Abstract The potential of coastal regimes for supporting permanent human settlement is tempered by the vulnerability of fixed infrastructure to changes in sea levels. First-millennium AD civic-ceremonial centers on the northern Gulf coast of Florida involved the construction of permanent infrastructure in support of regional gatherings that challenged sustainable settlement in the context of regressive sea. Although rising sea was the more common challenge over millennia of coastal dwelling, marine regression from periods of cooling climate slowly diminished near-shore habitat for fish and shellfish and eventually stranded settlements from tidal water. The challenge was especially acute for a community that built a tidal fish trap for summer solstice feasts, whose utility depended on the reliability of tides to flood the trap. High-resolution lidar data from the Richards Island fish trap enable accurate modeling of the effectiveness of the trap under current and lowered sea levels. The use-life history of the Richards Island fish trap illustrates the limits to intensification of coastal economies inherent to nonportable infrastructure whose utility is tide dependent—in particular, when demands on production are out of sync with optimal tidal conditions.